J O U R N A L O F C H E M I S T R Y Materials Synthesis and thermotropic liquid crystalline properties of calamitic molecules with laterally attached hydrophilic groups: Y-shaped three-block molecules which can form smectic and columnar mesophases Rene Plehnert, Jo�rg Andreas Schro�ter and Carsten Tschierske* Institute of Organic Chemistry, University Halle, D-06015 Halle, Kurt-Mothes-Str. 2, Germany.E-mail: coqfx@mlucom6.urz.uni-halle.de Received 23rd April 1998, Accepted 23rd September 1998 The synthesis and the thermotropic liquid crystalline properties of calamitic mesogens ( p-terphenyl derivatives, a biphenyl and a p-quintaphenyl derivative) with a laterally attached hydrophilic group (1,2-diol groups, primary and secondary amides, polyether chains, crown ether units, carbohydrate units, a hydrazide, a quaternary ammonium salt, a carboxylic acid and a sodium carboxylate) are reported.The compounds were investigated by means of polarizing microscopy and calorimetry. The influence of the type of the polar group, of the length of the rigid core and the position of the connection of the hydrophilic group with the rod-like rigid core have been investigated. Many of these amphiphilic molecules can form monolayer SA phases.If a suYcient amount of hydrogen bonding is available their mesophase stability can be higher than that of related compounds with other lateral substituents. Rectangular columnar mesophases can be found for compounds with rather large and flexible polar lateral substituents (polyether chains) fixed to the center of the rigid terphenyl unit.These columnar phases should represent ribbon phases resulting from the collapse of the smectic layers (modulated smectic phases). The proposed model is also related to that suggested for supermolecular structures of triblock copolymers. Thus, these molecules can be regarded as low molecular weight block compounds consisting of three diVerent and incompatible molecular parts.hydrophilic functional groups such as diol groups, polyether 1. Introduction chains, carbohydrate units or ionic groups were laterally Liquid crystalline materials are of great interest for material attached to a rigid rod-like oligo-p-phenylene rigid core. These science as well as for life science. Their properties can be tuned molecules are of special interest, because two diVerent organizby appropriate molecular design.Thus, it is well known that ing forces of liquid crystalline phases are perpendicularly the mesomorphic properties of calamitic liquid crystals can directed to each other in these compounds (Fig. 1). Firstly, largely be influenced by lateral substituents, like halogens,1–3 the tendency of the rigid calamitic units is to adopt an alkyl or alkoxy groups.4,5 This can influence the melting orientational long range order which is characteristic for points, the mesophase types, the dielectric properties, etc.In thermotropic liquid crystals and provides nematic and smectic most cases, however, a significant mesophase destabilization mesophases. Secondly, there is the tendency of amphiphilic is connected with this structural variation.Especially large molecules to segregate their incompatible (e.g. hydrophilic and lateral groups suppress smectic phases and therefore nearly all hydrophobic) parts into segregated regions, giving rise to large calamitic mesogens with long lateral alkyl chains show exclus- aggregates which themselves are the basis of lamellar, columnar ively nematic phases.5 However, in rare cases lateral substitu- or cubic thermotropic and lyotropic mesophases.8 In the ents can have a mesophase stabilizing eVect.The earliest compounds described here, the parallel arrangement of the example was provided by the laterally substituted 5-alkoxy- rigid units should be disturbed by the segregation of hydrophilic and hydrophobic parts of the molecules and, conversely, the aggregation of the amphiphilic molecules should be disturbed because of the unfavorable size and shape of their lipophilic parts.Indeed, these unusual molecules represent a new class of amphiphiles with an unique organization in Langmuir films at the air–water interface,9 but their liquid crystalline behavior is also remarkable.They represent novel amphotropic compounds10 which can form thermotropic as well as lyotropic liquid crystalline phases.11,12 The lyotropic naphthoic acids.6 The smectic tendency of the chloro substiphase behavior will be reported in detail in a separate paper.13 tuted naphthoic acid is remarkably high, whereas the naphthoic acid without the lateral chloro substituent is only a nematic liquid crystal.It seems that a significant mesophase stabilizing eVect is provided by the polar chloro substituent which can override its steric disturbance. Likewise suitable molecular design, especially the introduction of electron withdrawing substituents like cyano or nitro in laterally attached aromatic rings, can produce strongly branched calamitic mesogens with unexpectedly high mesophase stabilities.5,7 Fig. 1 Structure of the amphiphilic molecules under investigation. We have synthesized a novel class of liquid crystals in which J. Mater. Chem., 1998, 8, 2611–2626 2611Herein we describe the synthesis and summarize the results (compounds 33) to the 2¾-position and in some cases to the 3-position of the p-terphenyl unit. obtained during investigation of their thermotropic liquid crystalline properties. 2. Syntheses Pd0-catalyzed cross-coupling reactions between aryl halides and arylboronic acids (Suzuki coupling)14 represent the key steps of all syntheses which are outlined in Schemes 1–5. There are three diVerent approaches to the compounds 1–3 and 29–31 all carrying a lateral group connected via an ether linkage to the 2¾-position of the p-terphenyl rigid core.Compounds 1 and 3, which all have the 4,5-dihydroxy-2- oxapentyl group but diVer in the type of the terminal substituents, have been synthesized starting with 4-(2,5-dibromobenzyloxymethyl )-2,2-dimethyl-1,3-dioxolane 36 (Scheme 1). After cross-coupling of 36 with the appropriate 4-substituted phenylboronic acids, the 1,2-O-isopropylidene protecting groups were cleaved by acidolysis.In an analogous manner the quinquaphenyl derivative 5 was obtained by cross coupling of 36 with 4-(4-decyloxyphenyl )phenylboronic acid (Scheme 1). The terphenyl derivatives 29–31, which diVer in the structure of the lateral group in the 2¾-position, and the optically active compound (S)-1e were synthesized using another strategy shown in Scheme 2 for the syntheses of compounds 29b and First the p-terphenyl derivatives 1 and 3 (1: R=alkoxy; 3: R=alkyl, n=m=1) both carrying a lateral 4,5-dihydroxy-2- 29c.Here, the p-terphenyl rigid core was built up first and the lateral groups were introduced in a second step. This allowed oxapentyl group were synthesized and the influence of changes of the terminal substituents R was investigated.Afterwards a broad variation of the lateral hydrophilic groups. 2,5-Bis(4- decyloxyphenyl )toluene was obtained by cross coupling of we changed the structure of the rigid core. Besides m-terphenyl derivative 4, a biphenyl derivative 6, a molecule without a two equivalents of 4-decyloxyphenylboronic acid with 2,5- dibromotoluene.15 The methyl group was brominated using rigid unit 7 and a quinquaphenyl derivative 5 were synthesized.In the next step the position of the lateral hydrophilic group NBS.15 The 2,5-bis(4-decyloxyphenyl )benzyl bromide 3715 obtained was afterwards etherified with diVerent functionalized was shifted along the p-terphenyl unit (compounds 11 and 13). Finally, a wide variation of the structure of the lateral alcohols, followed by deprotection, if necessary. The best yields in the etherification step were obtained using phase hydrophilic group was carried out in the series of 4,4>- didecyloxy-p-terphenyl derivatives by appending amido groups transfer conditions.The optically active compound (S)-1e was obtained by etherification of 37 with enantiomerically pure (compounds 15–24), ionic groups (compounds 27 and 28), polyether chains (compounds 29, 30 and 34) or crethers (R)-(-)-4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane. 2612 J.Mater. Chem., 1998, 8, 2611–2626Scheme 3 Reagents and conditions: i, HOCH2CH2OCH2CHLCH2, Scheme 1 Reagents and conditions: i, NBS, AIBN, hn, CCl4, reflux, 2 NaOH, Bu4NHSO4, H2O, 60 °C, 12 h; ii, cat. OsO4, NMMNO, h; ii, NaOH, H2O, Bu4NHSO4, 60° C, 15 h; iii, cat.Pd(PPh3)4, acetone–H2O, 25 °C, 24 h. Na2CO3, H2O, benzene–EtOH, reflux, 4 h; iv, HCl, H2O–EtOH, reflux 2 h. benzyl bromides 39 and 40, respectively.18 The benzyl bromides 39 and 40 were synthesized as outlined in Scheme 4.18 Also compound 7, the biphenyl derivative 6 and the m-terphenyl derivative 4 were prepared in an analogous procedure to that given in Scheme 2 starting with 2,5-didecyloxybenzyl bromide,18 5-decyloxy-2-(4-decyloxyphenyl )benzyl bromide19 and 3,5-bis(4-decyloxyphenyl )benzyl bromide,20 respectively.All 2,5-bis(4-decyloxyphenyl )benzoyl derivatives 15–24 were synthesized according to Scheme 5. Cross-coupling of methyl 2,5-dibromobenzoate is possible with NaHCO3 as base in a water–glyme solvent system without saponification during the reaction (which would lead to a failure of the reaction).15 The 2,5-bis(4-decyloxyphenyl )benzoic acid 25 which is obtained after saponification is treated with oxalyl chloride21 to yield the acid chloride 26.The use of oxalyl chloride at low temperatures is crucial, because other conditions (e.g. SOCl2) would lead to an intramolecular Friedel–Crafts acylation with formation of 7-decyloxy-2-(4-decyloxyphenyl )fluoren-9-one. The acid chloride 26 was aminolyzed to give the amides 15–24.The crown compounds 33 were obtained by esterification of 25 with 2-hydroxymethyl substituted crown ethers. The detailed procedure and the analytical data for the crown compounds 33 are reported in a separate paper concerning their monolayer behavior.22 Additionally, two ionic amphiphiles were synthesized.The ammonium salt 28 was obtained by quaternization of triethylamine with 37.23 The sodium carboxylate 27 was isolated after saponification of the methyl carboxylate 14. Scheme 2 Reagents and conditions: i, cat. Pd(PPh3)4, Na2 CO3, H2O, benzene–EtOH, reflux, 4 h; ii, NBS, AIBN, hn, CCl4, reflux, 2 h; iii, NaOH, Bu4NHSO4, H2O, reflux, 15 h; iv, HCl, H2O–EtOH, 3.Experimental reflux, 2 h. 3.1. General Confirmation of the structures of intermediates and products Only compound 29a carrying the 7,8-dihydroxy-2,5-dioxaoctyl group was prepared in a slightly diVerent way, as shown was obtained by 1H and 13C NMR spectroscopy (Varian Unity 500 and Varian Gemini 200 spectrometers) and by mass in Scheme 3.The benzyl bromide 37 was at first etherified with 2-allyloxyethanol.16 The resulting allyl ether 38 was dihy- spectrometry (Intectra GmbH, AMD 402, electron impact, 70 eV). All materials were purified by chromatography and/or droxylated using catalytic amounts of OsO4 in the presence of the oxidant N-methylmorpholine N-oxide.17 recrystallization until constant transition temperatures were obtained. The purity was checked by thin layer chromatogra- The amphiphiles 11, 13 (Scheme 4), 34 and 35 (see Fig. 15) carrying their lateral substituents in the 2-position (compound phy (TLC, aluminum sheets, silica gel 60 F254 from Merck) and elemental analysis. Some compounds take up moisture 11) or in the 3-position (compounds 13, 34 and 35) at the pterphenyl rigid core were obtained in an analogous manner to during sample preparation which causes a deviation of the microanalysis from the calculated values.In these cases the the corresponding 2¾-substituted materials, starting with the J. Mater. Chem., 1998, 8, 2611–2626 2613Scheme 4 Reagents and conditions: i, C10H21Br, K2CO3, CH3CN, reflux, 17 h; ii, BuLi, THF, -78 °C, then B(OMe)3, -70 °C, then HCl, H2O; iii, cat.Pd(PPh3)4, Na2CO3, H2O–EtOH, reflux, 4 h; iv, NBS, AIBN, hn, CCl4, reflux, 2 h; v, NaOH, Bu4NHSO4, H2O, reflux, 12 h; vi, HCl, H2O–EtOH, reflux, 2 h. purity (>99%) was additionally checked by HPLC (Merck-Hitachi, RP-18, CH2Cl2–methanol 151). Microanalyses were performed using an LECO CHNS-932 elemental analyzer. 2,5-Dibromotoluene (Acros), N-bromosuccinimide (Merck), oxalyl chloride (Lancaster), osmium tetroxide (Berlin Chemie), N-methylmorpholine N-oxide solution (Aldrich), 4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane (Aldrich), (R)-(-)-4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane (Aldrich), 3-aminopropane-1,2-diol (Merck), 1-amino-1- deoxy-D-glucitol (Fluka), 1-deoxy-1-methylamino-D-glucitol (Acros) and 1,4,7,10,13-pentaoxa-16-azacyclooctadecane (Aldrich) were used as obtained. 2-Allyloxyethanol, phenylboronic acids,24 4-(7-hydroxy-2,5-dioxaheptyl )-2,2-dimethyl-1,3- dioxolane,25 4-(10-hydroxy-2,5,8-trioxadecyl )-2,2-dimethyl- 1,3-dioxolane,25 4-(9-hydroxynonyl )-2,2-dimethyl-1,3-dioxolane, 26 bromomethyl-substituted 4,4>-didecyloxy-p-terphenyls 3715, 3918 and 4018 and methyl 2,5-bis(4-decyloxyphenyl )benzoate 1415 were obtained according to the procedures described in the corresponding references.Transition temperatures were measured using a Mettler FP 82 HT hot stage and control unit in conjunction with a Nikon Optiphot-2 polarizing microscope and were confirmed using diVerential scanning calorimetry (Perkin-Elmer DSC-7, the transition enthalpies are collected in Table 1).Because some of the compounds are very hygroscopic, the samples were dried prior to investigation either in vacuo over phosphorus pentoxide for 48 h or by heating for 1 min to a temperature of approximately 150 °C. Afterwards the samples were immediately sealed and investigated. 3.2. Synthesis of the terphenyl derivatives 1 and 3 3.2.1. 4-(2,5-Dibromobenzyloxymethyl)-2,2-dimethyl-1,3- dioxolane 36.A solution of 2,5-dibromotoluene (20 mmol, 5 g) and N-bromosuccinimide (24 mmol, 4.27 g) in dry tetrachloromethane (50 ml ) was placed in a quartz flask and heated to the boiling point. AIBN (50 mg) was added and the refluxing mixture was irradiated with UV light (366 nm). After 2 h the mixture was cooled to room temperature and the succinimide Scheme 5 Reagents and conditions: i, cat.Pd(PPh3)4, NaHCO3, formed was filtered oV. The solvent was removed in vacuo and Glyme, H2O, reflux, 5 h; ii, NaOH, H2O, reflux, 4 h; iii, HCl, H2O, reflux, 2 h; iv, (COCl )2, 25°C, 1 h; v, HNR1R2, DMF, 80 °C, 4 h. the residue was purified by crystallization from ethanol. Yield: 2614 J. Mater. Chem., 1998, 8, 2611–2626Table 1 Phase transition enthalpiesa separated and the aqueous phase was extracted twice with diethyl ether (50 ml ).The combined organic phases were Compound DH/kJ mol-1 washed with brine and dried with Na2SO4. The solvent was removed in vacuo and the products obtained were purified by 1b K–Iso 43.2 SA–Iso 1.2 column chromatography (silica gel, chloroform). 1c K–SA 37.2 SA–Iso 3.8 1d K–SA 50.5 SA–Iso 4.4 1e K–SA 55.5 SA–Iso 6.1 4-[2,5-Bis(4-decyloxyphenyl)benzyloxymethyl]-2,2- 1f K–SA 66.2 SA–Iso 6.8 dimethyl-1,3-dioxolane.dH(200 MHz, CDCl3, J/Hz) 0.87 (t, J 1g K–SA 60.7 SA–Iso 7.6 6.7, 6H, CH3), 1.18–1.27 (m, 28H, CH2), 1.34 (s, 3H, CH3), 1h K–SA 70.7 SA–Iso 8.0 1.38 (s, 3H, CH3), 1.73–1.86 (m, 4H, OCH2CH2), 3.42 (dd, J 2 K–Iso 60.1 N–Iso 3.4 9.8, 5.8, 1H, PhCH2OCHAHB), 3.53 (dd, J 9.7, 5.5, 1H, 3b K–SA 30.8 SA–Iso 3.7 5 K–SA 29.2 SA–Iso 9.0 PhCH2OCHAHB), 3.71 (dd, J 8.3, 6.3, 1H, OCHAHB), 6 K–Iso 24.7 SA–Iso 2.7 3.96–4.20 (m, 5H, OCHAHB, PhOCH2), 4.23–4.29 (m, 1H, 9 K–SA 49.1 SA–N 0.8 N–Iso 1.4 CHO), 4.50 (s, 2H, PhCH2O), 6.93 (d, J 8.7, 2H, H-Ar), 6.96 10 K–SA 51.5 SA–Iso 6.7 (d, J 8.7, 2H, H-Ar), 7.26–7.28 (m, 2H, H-Ar), 7.29 (d, J 8.7, 11 K–SA 42.9 SA–Iso 7.8 1H, H-Ar), 7.48–7.53 (m, 1H, H-Ar), 7.55 (d, J 8.7, 2H, 12 K–SC 12.1 SC–SA–Iso 9.2 H-Ar), 7.70 (d, J 1.8, 1H, H-Ar). 13 K–SA 35.7 SA–Iso 8.6 17 K–SA 71.4 SA–Iso 6.3 18 K–SA 74.6 SA–Iso 5.0 3.2.4. Deprotection of the 1,2-diol groups. The 2,2-dimethyl- 19 K–SA 47.3 SA–Iso 3.3 1,3-dioxolane derivatives obtained by the cross-coupling reac- 20 K–SA 25.5 SA–Iso 1.6 tions were used, without further purification, for deprotection. 22 K–Iso 28.3 SA–Iso 2.3 The appropriate 2,2-dimethyl-1,3-dioxolane derivative 29b K–Iso 45.2 Colr–SA 1.2 SA–Iso 0.5 (1 mmol) was dissolved in ethanol (50 ml ) and 10% hydro- 29c K–Iso 43.2 Colr–Iso 1.9 30b K–Iso 49.3 SA–Iso 0.7 chloric acid (10 ml ) was added. Then, the mixture was heated 32 K–Iso 51.8 under reflux for 2 h. After cooling the solvent was evaporated 33a K–Iso 61.6 SA–N 0.4 N–Iso 1.0 and 50 ml water and 50 ml diethyl ether were added to the 33b K–Iso 0.8 SA–N–Iso 0.9 residue.The aqueous phase was extracted three times with 33c K–Iso 42.1 SA–N 0.1 N–Iso 0.4 diethyl ether (30 ml ). Afterwards, the combined organic phases 34a K–SA 40.0 SA–Iso 5.7 were washed with saturated NaHCO3 solution and water, and 34b K–SA 23.6 SA–Iso 2.7 34c K–SA 36.7 SA–Iso 1.0 dried with Na2SO4.The solvent was removed in vacuo and the crude product was purified by column chromatography aAbbreviations: K=crystalline solid, N=nematic phase, SA=smectic A phase, SC=smectic C phase, Colr=rectangular columnar and recrystallization. mesophase, Iso=isotropic liquid. 5-[2,5-Bis(4-ethoxyphenyl)phenyl]-4-oxapentane-1,2-diol 1a.Synthesized from 36 and 4-ethoxyphenylboronic acid. Crystallized from light petroleum (60–80 °C). Yield: 46%; 60%; mp 89 °C; dH(200 MHz, acetone, J/Hz) 4.69 (s, 2H, PhCH2Br), 7.45 (dd, J 8.5, 2.4, 1H, H-Ar), 7.60 (d, J 8.5, 1H, transitions/°C: K 124 (N 58) Iso; elemental analysis (%): found (calc. for C26H30O5): C, 73.82 (73.91); H, 7.29 (7.16); H-Ar), 7.82 (d, J 2.4, 1H, H-Ar). The 2,5-dibromobenzyl bromide obtained in this way was used without further purifi- dH(200 MHz, CDCl3, J/Hz) 1.43 (2t, J 6.9, 6H, CH3), 1.76 (s, broad, 2H, OH), 3.4–3.7 (m, 4H, OCH2), 3.75–3.9 [m, 1H, cation for the next step.In a two-necked flask equipped with a reflux condenser and CH(OH)], 4.06 (t, J 6.8, 2H, PhOCH2), 4.09 (t, J 7.0, 2H, PhOCH2), 4.49 (s, 2H, PhCH2O), 6.93 (d, J 8.5, 2H, H-Ar), a magnetic stirring bar, Bu4NHSO4 (30 mg) was added to a mixture consisting of 4-hydroxymethyl-2,2-dimethyl-1,3- 6.98 (d, J 8.6, 2H, H-Ar), 7.3–7.35 (m, 3H, H-Ar), 7.5–7.6 (m, 3H, H-Ar), 7.63 (d, J 1.8, 1H, H-Ar); m/z (%) 422 dioxolane (0.1 mol, 13.2 g), 2,5-dibromobenzyl bromide (0.01 mol, 3.3 g) and 50% aq.NaOH (15 ml ) under argon ([M]+, 100). atmosphere. The mixture was stirred rapidly at 60 °C for 15 h. After cooling 50 ml water and 50 ml diethyl ether were added. 5-[2,5-Bis(4-hexyloxyphenyl)phenyl]-4-oxapentane-1,2-diol 1b. Synthesized from 36 and 4-hexyloxyphenylboronic acid. The organic phase was separated and the aqueous phase was extracted three times with diethyl ether (100 ml ). The com- Crystallized from n-hexane. Yield: 44%; transitions/°C: K 80 (SA 71) Iso; elemental analysis (%): found (calc.for C34H46O5): bined organic phases were dried with Na2SO4 and afterwards, the solvent was removed in vacuo. The residue was purified by C, 75.73 (76.37); H, 8.83 (8.67); dH(200 MHz, CDCl3, J/Hz) 0.91 (t, J 6.3, 6H, CH3), 1.21–1.58 (m, 12H, CH2), 1.69–1.88 column chromatography (silica gel, chloroform). Yield: 42%; yellow oil; dH(500 MHz, CDCl3, J/Hz) 1.37 (s, 3H, CH3), (m, 4H, OCH2CH2), 1.95 (dd, 1H, CH2OH), 2.42 [d, 1H, CH(OH)], 3.45–3.68 (m, 4H, OCH2), 3.74–3.86 [m, 1H, 1.43 (s, 3H, CH3), 3.57 (dd, J 10.0, 5.1, 1H, PhCH2OCHAHB), 3.64 (dd, J 10.0, 5.6, 1H, PhCH2OCHAHB), 3.78 (dd, J 8.3, CH(OH)], 3.99 (t, J 6.2, 4H, PhOCH2), 4.49 (s, 2H, PhCH2O), 6.91 (d, J 8.5, 2H, H-Ar), 6.96 (d, J 8.6, 2H, H-Ar), 7.29 (d, 6.3, 1H, OCHAHB), 4.08 (dd, J 8.3, 6.4, 1H, OCHAHB), 4.31–4.35 (m, 1H, CHO), 4.57 (m, 2H, PhCH2O), 7.25 (dd,J J8.5, 2H, H-Ar), 7.31 (d, J 8.3, 1H, H-Ar), 7.49–7.59 (m, 3H, H-Ar), 7.62 (d, J 1.8, 1H, H-Ar); m/z (%) 534 ([M]+, 100). 8.3, 2.4, 1H, H-Ar), 7.36 (d, J 8.3, 1H, H-Ar), 7.62 (d, J 2.4, 1H, H-Ar). 5-[2,5-Bis(4-octyloxyphenyl)phenyl]-4-oxapentane-1,2-diol 1c. Synthesized from 36 (1 mmol, 380 mg) and 4-octyloxyphen- 3.2.3. General procedure for the Pd-catalyzed cross-coupling reactions.In a two-necked flask equipped with a reflux con- ylboronic acid (2.4 mmol, 600 mg). Crystallized from light petroleum (60–80 °C) and afterwards from methanol. Yield: denser and a magnetic stirring bar, Pd(PPh3)4 (0.03 mmol, 35 mg, 3 mol%) was added under an argon atmosphere to a 35%; transitions/°C: K 79 SA 102 Iso; elemental analysis (%): found (calc.for C38H54O5): C, 77.19 (77.25); H, 9.03 (9.21); mixture consisting of the appropriate dibromobenzene derivative (1 mmol), the boronic acid (2.4 mmol), benzene (30 ml ), dH(200 MHz, CDCl3, J/Hz) 0.88 (t, J 6.6, 6H, CH3), 1.29–1.37 (m, 16H, CH2), 1.43–1.48 (m, 4H, OCH2CH2CH2), 1.76–1.83 ethanol (30 ml ) and 2 M Na2CO3 solution (30 ml ).The mixture was stirred at reflux temperature for 4 h. After cooling the (m, 4H, OCH2CH2), 3.48–3.68 (m, 4H, OCH2), 3.80–3.89 [m, 1H, CH(OH)], 3.99 (t, J 6.5, 4H, PhOCH2), 4.50 (s, 2H, solvent was evaporated and the residue dissolved in diethyl ether (30 ml ) and water (30 ml ). The organic phase was PhCH2O), 6.93–6.98 (m, 4H, H-Ar), 7.28 (d, J 8.4, 2H, HJ.Mater. Chem., 1998, 8, 2611–2626 2615Ar), 7.31 (d, J 8.0, 1H, H-Ar), 7.51–7.53 (m, 1H, H-Ar), 7.54 J 8.2, 1H, H-Ar), 7.47–7.56 (m, 3H, H-Ar), 7.63 (d, J 1.8, 1H, H-Ar); m/z (%) 758 ([M]+, 100). (d, J 8.6, 2H, H-Ar), 7.64 (d, J 1.6, 1H, H-Ar). 5-[2,5-Bis(4-nonyloxyphenyl)phenyl]-4-oxapentane-1,2-diol 5-[2,5-Bis(4-propylphenyl)phenyl]-4-oxapentane-1,2-diol 1d.Synthesized from 36 (1 mmol, 380 mg) and 4-nonyloxy- 3a. Synthesized from 36 and 4-propylphenylboronic acid. phenylboronic acid (2.4 mmol, 632 mg). Crystallized from Crystallized from n-hexane. Yield: 37%; mp 60 °C; elemental light petroleum (60–80 °C). Yield: 32%; transitions/°C: K 82 analysis (%): found (calc. for C28H34O3): C, 79.72 (80.35); H, SA 106 Iso; elemental analysis (%): found (calc.for C40H58O5): 7.96 (8.19); dH(200 MHz, CDCl3, J/Hz) 0.97 (t, J 7.2, 3H, C, 77.56 (77.63); H, 9.53 (9.45); dH(200 MHz, CDCl3, J/Hz) CH3), 0.98 (t, J 7.2, 3H, CH3), 1.59–1.78 (m, 4H, CH2), 2.62 0.86 (t, J 6.4, 6H, CH3), 1.27–1.34 (m, 20H, CH2), 1.42–1.47 (t, J 7.5, 4H, PhCH2), 3.4–3.7 (m, 4H, CH2O), 3.7–3.9 [m, (m, 4H, OCH2CH2CH2), 1.75–1.82 (m, 4H, OCH2CH2), 1H, CH(OH)], 4.52 (s, 2H, PhCH2O), 7.20–7.31 (m, 7H, H- 3.44–3.67 (m, 4H, OCH2), 3.80–3.85 [m, 1H, CH(OH)], 3.98 Ar), 7.52–7.59 (m, 3H, H-Ar), 7.62 (d, J 2.0, 1H, H-Ar); m/z (t, J 6.6, 4H, PhOCH2), 4.50 (s, 2H, PhCH2O), 6.92–6.97 (m, (%) 418 ([M]+, 100). 4H, H-Ar), 7.26–7.31 (m, 3H, H-Ar), 7.49–7.54 (m, 3H, H-Ar), 7.63 (d, J 2.0, 1H, H-Ar). 5-[2,5-Bis(4-undecylphenyl)phenyl]-4-oxapentane-1,2-diol 3b.Synthesized from 36 and 4-undecylphenylboronic acid. 5-[2,5-Bis(4-decyloxyphenyl)phenyl]-4-oxapentane-1,2-diol Crystallized from n-hexane. Yield: 46%; transitions/°C: K 63 1e. Synthesized from 36 and 4-decyloxyphenylboronic acid. SA 78 Iso; elemental analysis (%): found (calc. for C44H66O3): Crystallized from n-hexane. Yield: 54%; transitions/°C: K 83 C, 81.98 (82.19); H, 10.52 (10.35); dH(250 MHz, CDCl3, SA 114 Iso; elemental analysis (%): found (calc.for C42H62O5): J/Hz) 0.71 (t, J 6.5, 6H, CH3), 1.0–1.3 (m, 32H, CH2), 1.5–1.6 C, 77.74 (77.98); H, 9.85 (9.66); dH(200 MHz, CDCl3, J/Hz) (m, 4H, CH2), 1.73 (dd, J 4.0, 1H, CH2OH), 2.34 [d, J 5.0, 0.87 (t, J 6.5, 6H, CH3), 1.18–1.58 (m, 28H, CH2), 1.71–1.89 1H, CH(OH)], 2.47 (t, J 6.4, 4H, PhCH2), 3.3–3.6 (m, 4H, (m, 4H, OCH2CH2), 3.43–3.72 (m, 4H, OCH2), 3.77–3.91 [m, OCH2), 3.6–3.7 [m, 1H, CH(OH)], 4.37 (s, 2H, PhCH2O), 1H, CH(OH)], 3.99 (t, J 6.5, 4H, PhOCH2), 4.50 (s, 2H, 7.1–7.45 (m, 10H, H-Ar), 7.51 (d, J 1.4, 1H, H-Ar).PhCH2O), 6.92 (d, J 8.6, 2H, H-Ar), 6.96 (d, J 8.7, 2H, HAr), 7.29 (d, J 8.5, 2H, H-Ar), 7.33 (d, J 8.2, 1H, H-Ar), 3.3. 5-{2,5-Bis[4-[4-decyloxyphenyl )phenyl]phenyl}-4- 7.4–4.5 (m, 1H, H-Ar), 7.55 (d, J 8.8, 2H, H-Ar), 7.64 (d, J oxapentane-1,2-diol 5 1.8, 1H, H-Ar); dC(125 MHz, CDCl3) 14.09 (CH3), 22.67, 26.08, 26.10, 29.32, 29.41, 29.56, 29.60, 31.91 (CH2), 64.08 Synthesized from 36 (1 mmol, 380 mg) and 4-(4-decyloxyphen- (CH2OH), 68.15 (PhOCH2), 68.17 (PhOCH2), 70.53 yl )phenylboronic acid (2.4 mmol, 850 mg) according to pro- [OCH2CH(OH)], 71.80 [OCH2CH(OH)], 72.03 (PhCH2O), cedures 3.2.3 and 3.2.4.Crystallized from n-hexane–ethyl 114.26, 114.90, 126.19, 127.60, 128.05, 130.16, 130.68, 132.67, acetate. Yield: 43%; transitions/°C: K 152 SA 258 Iso; elemental 132.92, 135.22, 139.81, 140.14, 158.57, 158.89 (C-Ar); m/z (%) analysis (%): found (calc. for C54H70O5): C, 80.92 (81.16); H, 646 ([M]+, 100). 8.98 (8.83); dH(200 MHz, CDCl3, J/Hz) 0.88 (t, J 6.4, 6H, CH3), 1.2–1.6 (m, 28H, CH2), 1.7–1.9 (m, 4H, OCH2CH2), 1.94 (dd, J 4.0, 1H, CH2OH), 2.43 [d, J 5.0, 1H, CH(OH)], 5-[2,5-Bis(4-undecyloxyphenyl)phenyl]-4-oxapentane-1,2- 3.5–3.77 (m, 4H, OCH2), 3.8–3.95 [m, 1H, CH(OH)], 4.00 (t, diol 1f. Synthesized from 36 (1 mmol, 380 mg) and 4-undecyl- J 6.5, 4H, PhOCH2), 4.57 (s, 2H, PhCH2O), 6.98 (d, J 8.8, oxyphenylboronic acid (2.4 mmol, 701 mg).Crystallized from 4H, H-Ar), 7.4–7.7 (m, 14H, H-Ar), 7.76 (d, J 1.7, 1H, H-Ar); light petroleum (60–80 °C). Yield: 39%; transitions/°C: K 89 m/z (%) 798 ([M]+, 100). SA 114 Iso; elemental analysis (%): found (calc. for C44H66O5): C, 78.46 (78.24); H, 9.63 (9.86); dH(200 MHz, CDCl3, J/Hz) 0.86 (t, J 6.5, 6H, CH3), 1.26–1.46 (m, 32H, CH2), 1.76–1.83 3.4.Synthesis of the diols (S)-1e, 4, 6, 7, 11, 13, 29b,c, 31, (m, 4H, OCH2CH2), 3.43–3.71 (m, 4H, OCH2), 3.79–3.86 [m, 34b,c, 35a,b 1H, CH(OH)], 3.99 (t, J 6.5, 4H, PhOCH2), 4.50 (s, 2H, 3.4.1. General procedure for the synthesis of benzyl ethers. PhCH2O), 6.94 (d, J 8.6, 2H, H-Ar), 6.96 (d, J 8.8, 2H, HIn a two-necked flask equipped with a reflux condenser and a Ar), 7.26–7.33 (m, 3H, H-Ar), 7.49–7.56 (m, 3H, H-Ar), 7.63 magnetic stirring bar, Bu4NHSO4 (5 mg) and 50% aq.NaOH (d, J 2.0, 1H, H-Ar). (3 ml ) were added to a solution of the alcohol (15 mmol) and the benzyl bromide (1.5 mmol) in 10 ml toluene under argon 5-[2,5-Bis(4-dodecyloxyphenyl)phenyl]-4-oxapentane-1,2- atmosphere. The mixture was stirred violently at 60 °C for diol 1g.Synthesized from 36 and 4-dodecyloxyphenylboronic 15 h. After cooling 30 ml water and 30 ml diethyl ether were acid. Crystallized first from light petroleum (60–80 °C) and added. The organic phase was separated and the aqueous afterwards from methanol. Yield: 47%; transitions/°C: K 86 phase was extracted with diethyl ether. The combined organic SA 116 Iso; dH(200 MHz, CDCl3, J/Hz) 0.87 (t, J 6.6, 6H, phases were dried with Na2SO4 and afterwards the solvent CH3), 1.27–1.55 (m, 36H, CH2), 1.77–1.84 (m, 4H, was removed in vacuo.The residue was purified by column OCH2CH2), 1.99 (br s, 2H, OH), 3.42–3.75 (m, 4H, OCH2), chromatography. 3.76–3.94 [m, 1H, CH(OH)], 3.99 (t, J 6.6, 4H, PhOCH2), 4.50 (s, 2H, PhCH2O), 6.9–7.0 (m, 4H, H-Ar), 7.27–7.39 (m, 3.4.2. Deprotection of the 1,2-diol group.The 2,2-dimethyl- 3H, H-Ar), 7.5–7.7 (m, 4H, H-Ar); m/z (%) 702 ([M]+, 100). 1,3-dioxolane derivatives obtained were used, without further purification, for deprotection as described in 3.2.4. 5-[2,5-Bis(4-tetradecyloxyphenyl)phenyl]-4-oxapentane- 1,2-diol 1h. Synthesized from 36 and 4-tetradecyloxyphenylboronic acid. Crystallized from ethanol.Yield: 48%; (S)-5-[2,5-Bis(4-decyloxyphenyl )phenyl]-4-oxapentane-1,2- diol (S)-1e. Synthesized from (R)-(-)-4-hydroxymethyl-2,2- transitions/°C: K 95 SA 118 Iso; elemental analysis (%): found (calc. for C50H78O5): C, 78.82 (79.09); H, 10.35 (10.36); dimethyl-1,3-dioxolane and 37. Eluent: chloroform–methanol (1051). Crystallized from n-hexane. Yield: 28%; transitions/°C: dH(200 MHz, CDCl3, J/Hz) 0.87 (t, J 6.4, 6H, CH3), 1.1–1.6 (m, 42H, CH2), 1.7–1.9 (m, 4H, OCH2CH2), 3.37–3.73 (m, K 83 SA 114 Iso; elemental analysis (%): found (calc.for C42H62O5): C, 77.86 (77.96); H, 9.70 (9.67); [a]58925+1.9, 4H, OCH2), 3.78–3.91 [m, 1H, CH(OH)], 3.99 (t, J 6.3, 4H, PhOCH2), 4.50 (s, 2H, PhCH2O), 6.93 (d, J 8.4, 2H, H-Ar), [a]43625+4.9 (c 1.0, CHCl3); all other analytical data correspond to those given for rac-1e. 6.96 (d, J 8.6, 2H, H-Ar), 7.29 (d, J 8.3, 2H, H-Ar), 7.31 (d, 2616 J. Mater. Chem., 1998, 8, 2611–26265-[3,5-Bis(4-decyloxyphenyl)phenyl]-4-oxapentane-1,2-diol 113.90, 114.84, 115.12, 126.37, 128.01, 129.60, 131.21, 132.94, 133.87, 136.13, 138.87, 139.43, 158.61, 158.83 (C-Ar); m/z (%) 4. Synthesized from 4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane and 3,5-bis(4-decyloxyphenyl )benzyl bromide.20 Eluent: 646 ([M]+, 100).chloroform–methanol (1051). Crystallized from n-hexane– ethyl acetate. Yield: 43%; mp 67 °C; elemental analysis (%): 5-{2-Decyloxy-5-[4-(4-decyloxyphenyl)phenyl]phenyl}-4- oxapentane-1,2-diol 13. Synthesized from 4-hydroxymethyl- found (calc. for C42H62O5): C, 77.88 (77.98); H, 9.78 (9.66); dH(500 MHz, CDCl3, J/Hz) 0.87 (t, J 6.5, 6H, CH3), 1.2–1.5 2,2-dimethyl-1,3-dioxolane and 40.Eluent: chloroform–methanol (1051). Crystallized from n-hexane. Yield: 21%; (m, 28H, CH2), 1.7–1.8 (m, 4H, OCH2CH2), 2.06 (br s, 1H, CH2OH), 2.59 [br s, 1H, CH(OH)], 3.58–3.68 (m, 3H, transitions/°C: K 75 SA 144 Iso; elemental analysis (%): found (calc. for C42H62O5): C, 77.69 (77.98); H, 9.82 (9.66); CH2OH, OCHAHB), 3.72 (dd, J 11.3, 3.8, 1H, OCHAHB), 3.92 [m, 1H, CH(OH)], 3.99 (t, J 6.5, 4H, PhOCH2), 4.64 (s, dH(500 MHz, CDCl3, J/Hz) 0.88 (t, J 6.5, 6H, CH3), 1.2–1.4 (m, 24H, CH2), 1.4–1.5 (m, 4H, OCH2CH2CH2), 1.75–1.85 2H, PhCH2O), 6.96 (d, J 8.6, 4H, H-Ar), 7.41 (d, J 1.6, 2H, H-Ar), 7.53 (d, J 8.7, 4H, H-Ar), 7.64 (d, J 1.6, 1H, H-Ar); (m, 4H, OCH2CH2), 2.14 (br s, 1H, CH2OH), 2.72 [br s, 1H, CH(OH)], 3.6–3.8 (m, 4H, OCH2), 3.88–3.95 [m, 1H, m/z (%) 646 ([M]+, 100).CH(OH)], 3.99 (t, J 6.6, 2H, PhOCH2), 4.02 (t, J 6.6, 2H, PhOCH2), 4.62 (d, J 12.0, 1H, PhCHAHBO), 4.66 (d, J 12.0, 5-[5-Decyloxy-2-(4-decyloxyphenyl)phenyl]-4-oxapentane- 1,2-diol 6. Synthesized from 4-hydroxymethyl-2,2-dimethyl- 2H, PhCHAHBO), 6.93 (d, J 8.5, 1H, H-Ar) 6.96 (d, J 8.7, 2H, H-Ar), 7.2–7.6 (m, 3H, H-Ar), 7.59 (s, 5H, H-Ar); 1,3-dioxolane and 5-decyloxy-2-(4-decyloxyphenyl )benzylbromide. 18 Eluent: chloroform–methanol (1050.5).Crystallized dC(125 MHz, CDCl3) 14.07 (CH3), 22.66, 26.07, 26.11, 29.27, 29.31, 29.38, 29.41, 29.58, 29.60, 31.90, (CH2), 64.27 from methanol. Yield: 20%; transitions/°C: K 43 (SA 28) Iso; elemental analysis (%): found (calc.for C36H58O5): C, 75.58 (CH2OH), 68.18 (PhOCH2), 68.42 (PhOCH2), 68.95 [OCH2CH(OH)], 70.50 [OCH2CH(OH)], 72.26 (PhCH2O), (75.75); H, 10.37 (10.24); dH(500 MHz, CDCl3, J/Hz) 0.86 (t, J 6.5, 6H, CH3), 1.2–1.4 (m, 24H, CH2), 1.4–1.5 (m, 4H, 111.77, 114.89, 126.52, 126.99, 127.45, 127.93, 127.97, 133.04, 133.08, 138.95, 139.30, 156.49, 158.80 (C-Ar); m/z (%) 646 OCH2CH2CH2), 1.7–1.8 [m, 4H, OCH2CH2), 1.96 (dd, J 6.0, 6.0, 1H, CH2OH), 2.43 [d, J 5.1 1H, CH(OH)], 3.43 (dd, J ([M]+, 100). 9.6, 6.2, 1H, OCHAHB), 3.48 (dd, J 9.5, 3.9 1H, OCHAHB), 3.54–3.6 (m, 1H, CHAHBOH), 3.62–3.69 (m, 1H, CHAHBOH), 11-[2,5-Bis(4-decyloxyphenyl)phenyl]-4,7,10- trioxaundecane-1,2-diol 29b. Synthesized from 4-(7-hydroxy- 3.78–3.85 [m, 1H, CH(OH)], 3.96 (t, J 6.5, 2H, PhOCH2), 3.97 (t, J 6.5, 2H, PhOCH2), 4.41 (s, 2H, PhCH2O), 6.86 (dd, 2,5-dioxaheptyl )-2,2-dimethyl-1,3-dioxolane and 37.Eluent: chloroform–methanol (1050.3). Yield: 17%; transitions/°C: K J 8.6, 2.7, 1H, H-Ar), 6.91 (d, J 8.8, 2H, H-Ar), 6.99 (d, J 2.4, 1H, H-Ar), 7.16 (d, J 8.6, 1H, H-Ar), 7.19 (d, J 8.8, 2H, 54 (Colr 40 SA 48) Iso; elemental analysis (%): found (calc. for C46H70O7): C, 75.04 (75.16); H, 9.86 (9.60); dH(200 MHz, H-Ar); dC(125 MHz, CDCl3) 14.08 (CH3), 22.67, 26.10, 29.32, 29.35, 29.42, 29.56, 29.59, 31.90 (CH2), 64.10 (CH2OH), 68.14 CDCl3, J/Hz) 0.87 (t, J 6.7, 6H, CH3), 1.17–1.55 (m, 28H, CH2), 1.7–1.9 (m, 4H, OCH2CH2), 2.3 (br s, 2H, OH), (PhOCH2), 68.16 (PhOCH2), 70.51 [OCH2CH(OH)], 71.68 [OCH2CH(OH)], 71.99 (PhCH2O), 113.87, 114.18, 114.45, 3.45–3.66 (m, 12H, OCH2), 3.74–3.82 [m 1H, CH(OH)], 3.98 (t, J 6.5, 4H, PhOCH2), 4.48 (s, 2H, PhCH2O), 6.92 (d, J 8.7, 115.03, 130.24, 131.23, 132.77, 134.0, 136.18, 158.30, 158.39 (C-Ar); m/z (%) 570 ([M]+, 100). 2H, H-Ar), 6.96 (d, J 8.7, 2H, H-Ar), 7.29 (d, J 8.0, 2H, HAr), 7.31 (d, 1H, J 8.7, H-Ar), 7.50 (dd, J 8.0, 2.0, 1H, HAr), 7.57 (d, J 8.8, 2H, H-Ar), 7.72 (d, J 1.8, 1H, H-Ar); 5-(2,5-Didecyloxphenyl)-4-oxapentane-1,2-diol 7.Synthesized from 4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane dC(125 MHz, CDCl3) 14.07 (CH3), 22.65, 26.07, 26.09, 29.30, 29.32, 29.34, 29.41, 29.55, 29.57, 30.84, 31.88, (CH2), 63.91 and 2,5-didecyloxybenzyl bromide.18 Eluent: chloroform– methanol (1050.5). Crystallized from n-pentane. Yield: 34%; (CH2OH), 68.11 (PhOCH2), 68.15 (PhOCH2), 69.62, 70.49, 70.53, 70.57, 70.81, [OCH2CH(OH), OCH2], 71.28 mp 42 °C; elemental analysis (%): found (calc.for C30H54O5): C, 72.65 (72.83); H, 11.34 (11.00); dH(200 MHz, CDCl3, [OC H2CH(OH)], 73.00 (PhCH2O), 114.16, 114.82, 125.85, 127.53, 128.05, 130.34, 130.46, 132.72, 133.12, 135.60, 139.63, J/Hz) 0.85 (t, J 6.4, 6H, CH3), 1.1–1.5 (m, 28H, CH2), 1.7–1.8 (m, 4H, OCH2CH2), 2.18 (br s, 1H, CH2OH), 2.76 [br s, 1H, 139.99, 158.46, 158.79 (C-Ar); m/z (%) 734 ([M]+, 100).CH(OH)], 3.5–3.7 [m, 5H, OCH2, CH(OH)], 3.87 (t, J 6.5, 2H, PhOCH2), 3.89 (t, J 6.6, 2H, PhOCH2), 4.50 (d, J 11.9, 14-[2,5-Bis(4-decyloxyphenyl)phenyl]-4,7,10,13- tetraoxatetradecane-1,2-diol 29c. Synthesized from 4-(10- 1H, PhCHAHBO), 4.57 (d, J 12.1, 1H, PhCHAHBO), 6.75 (s, 1H, H-Ar), 6.76 (s, 1H, H-Ar), 6.87 (s, 1H, H-Ar); m/z (%) hydroxy-2,5,8-trioxadecyl )-2,2-dimethyl-1,3-dioxolane and 37.Eluent: chloroform–methanol (1050.3). Yield: 16%; 494 ([M]+, 100). transitions/°C: K 45 (Colr 40) Iso; elemental analysis (%): found (calc. for C48H74O8): C, 73.56 (74.00); H, 9.53 (9.57); 5-{5-Decyloxy-2-[4-(4-decyloxyphenyl)phenyl]phenyl}-4- oxapentane-1,2-diol 11. Synthesized from 4-hydroxymethyl- dH(200 MHz, CDCl3, J/Hz) 0.87 (t, J 6.7, 6H, CH3), 1.27–1.45 (m, 28H, CH2), 1.76–1.83 (m, 4H, OCH2CH2), 3.50–3.62 (m, 2,2-dimethyl-1,3-dioxolane and 39.Eluent: chloroform–methanol (1050.5). Crystallized from n-hexane. Yield: 23%; 16H, OCH2), 3.71–3.87 [m, 1H, CH(OH)], 3.98 (t, J 6.5, 4H, PhOCH2), 4.49 (s, 2H, PhCH2O), 6.93 (d, J 8.5, 2H, H-Ar), transitions/°C: K 86 SA 114 Iso; elemental analysis (%): found (calc.for C42H62O5): C, 77.83 (77.98); H, 9.79 (9.66); dH 6.96 (d, J 8.6, 2H, H-Ar), 7.26–7.33 (m, 3H, H-Ar), 7.49 (dd, J 8.7, 1.7, 1H, H-Ar), 7.55 (d, J 8.7, 2H, H-Ar), 7.71 (d, J (200 MHz, CDCl3, J/Hz) 0.88 (t, J 6.5, 6H, CH3), 1.2–1.6 (m, 28H, CH2), 1.75–1.84 (m, 4H, OCH2CH2), 1.92 (dd, J 1.7, 1H, H-Ar); m/z (%) 778 ([M]+, 100). 6.0, 6.0, 1H, CH2OH), 2.41 [d, J 5.1, 1H, CH(OH)], 3.44–3.52 (m, 2H, OCH2), 3.55–3.60 (m, 1H, CHAHBOH), 3.62–3.68 13-[2,5-Bis(4-decyloxyphenyl)phenyl]-12-oxatridecane-1,2- diol 31. Synthesized from 4-(9-hydroxynonyl )-2,2-dimethyl- (m, 1H, CHAHBOH), 3.79–3.85 [m, 1H, CH(OH)], 3.98 (t, J 6.5, 2H, PhOCH2), 3.99 (t, J 6.5, 2H, PhOCH2), 4.47 (s, 2H, 1,3-dioxolane and 37. Eluent: chloroform–methanol (1051).Crystallized from n-hexane. Yield: 21%; transitions/°C: K 54 PhCH2O), 6.89 (dd, J 8.6, 2.6, 1H, H-Ar), 6.96 (d, J 8.8, 2H, H-Ar), 7.08 (d, J 2.4, 1H, H-Ar), 7.22 (d, J 8.8, 1H, H- (N 30) Iso; elemental analysis (%): found (calc. for C50H78O5): C, 78.86 (79.11); H, 10.74 (10.36); dH(200 MHz, CDCl3, Ar), 7.34 (d, J 8.1, 2H, H-Ar), 7.52–7.59 (2d, 4H, H-Ar); dC(50 MHz, CDCl3) 14.09 (CH3), 22.65, 26.05, 29.30, 29.39, J/Hz) 0.88 (t, J 6.5, 6H, CH3), 1.24–1.4 (m, 34H, CH2), 1.4–1.62 (m, 8H, CH2), 1.77–1.85 (m, 6H, OCH2CH2), 3.43 29.55, 31.87 (CH2), 64.02 (CH2OH), 68.10 (PhOCH2), 70.47 [OCH2CH(OH)], 71.64 [OCH2CH(OH)], 71.99 (PhCH2O), (t, J 6.5, 2H, PhCH2OCH2), 3.38–3.46 [m, 1H, CHAHBOH], J.Mater. Chem., 1998, 8, 2611–2626 26173.61–3.73, [m, 2H, CHAHBOH, CH(OH)], 4.02 (t, J 6.5, 2H, 7.31 (d, J 8.6, 1H, H-Ar), 7.52 (dd, J 8.1, 1.7, 1H, H-Ar), 7.55 PhOCH2), 4.04 (t, J 6.5, 2H, PhOCH2), 4.42 (s, 2H, PhCH2O), (d, J 8.7, 2H, H-Ar), 7.72 (d, J 1.7, 1H, H-Ar); m/z (%) 704 6.94 (d, J 8.5, 2H, H-Ar), 6.97 (d, J 8.6, 2H, H-Ar), 7.29–7.35 ([M]+, 67), 556 (59).(m, 3H, H-Ar), 7.50 (dd, J 8.7, 1.7, 1H, H-Ar), 7.56 (d, J 8.7, 2H, H-Ar), 7.71 (d, J 1.8, 1H, H-Ar); m/z (%) 758 ([M]+, 100). 14-[2,5-Bis(4-decyloxyphenyl )phenyl]-4,7,10,13- tetraoxatetradecanol 30b. Synthesized from tetraethylene glycol 11-{2-Decyloxy-5-[4-(4-decyloxyphenyl)phenyl]phenyl}- and 37. Eluent: chloroform–methanol (1050.5). Crystallized 4,7,10-trioxaundecane-1,2-diol 34b. Synthesized from 4-(7- from n-hexane. Yield: 25%; transitions/°C: K 44 (SA 31) Iso; hydroxy-2,5-dioxaheptyl )-2,2-dimethyl-1,3-dioxolane and 40.elemental analysis (%): found (calc. for C47H72O7): C, 75.08 Eluent: chloroform–methanol (1050.5). Yield: 32%; (75.36); H, 9.76 (9.69); dH(200 MHz, CDCl3, J/Hz) 0.91 (t, J transitions/°C: K 36 SA 97 Iso; dH(400 MHz, CDCl3, J/Hz) 6.4, 6H, CH3), 1.2–1.6 (m, 28H, CH2), 1.75–1.92 (m, 4H, 0.87 (t, J 6.4, 6H, CH3), 1.27–1.36 (m, 24H, CH2), 1.42–1.49 OCH2CH2), 3.54–3.78 (m, 16H, OCH2), 4.01 (t, J 6.5, 4H, (m, 4H, OCH2CH2CH2), 1.75–1.83 (m, 4H, OCH2CH2), 2.28 PhOCH2), 4.52 (s, 2H, PhCH2O), 6.93 (d, J 8.5, 2H, H-Ar), (br s, 2H, OH), 3.50–3.71 (m, 12H, OCH2), 3.78–3.83 [m, 6.96 (d, J 8.6, 2H, H-Ar), 7.28 (d, J 8.5, 2H, H-Ar), 7.31 (d, 1H, CH(OH)], 3.99 (t, J 6.6, 2H, PhOCH2), 4.00 (t, J 6.4, J 8.6, 1H, H-Ar), 7.5–7.6 (m, 3H, H-Ar), 7.74 (d, J 1.7, 1H, 2H, PhOCH2), 4.66 (s, 2H, PhCH2O), 6.90 (d, J 8.4, 1H, HH- Ar); m/z (%) 748 ([M]+, 68), 704 (27).Ar), 6.96 (d, J 8.8, 2H, H-Ar), 7.48 (dd, J 8.4, 2.3, 1H, HAr), 7.54 (d, J 8.6, 2H, H-Ar), 7.57–7.62 (m, 4H, H-Ar), 7.68 (d, J 2.3, 1H, H-Ar); m/z (%) 734 ([M]+, 74), 660 (79). 3.6. Synthesis of the p-terphenyl derivatives 29a and 34a 14-{2-Decyloxy-5-[4-(4-decyloxyphenyl)phenyl]phenyl}- At first the appropriate bromomethyl substituted 4,4>-didecyl- 4,7,10,13-tetraoxatetradecane-1,2-diol 34c.Synthesized from oxy-p-terphenyl derivatives 37 and 40 were etherified according 4-(10-hydroxy-2,5,8-trioxadecyl )-2,2-dimethyl-1,3-dioxolane to procedure 3.4.1 with 2-allyloxyethanol to give the allyl and 40.Eluent: chloroform–methanol (1050.3). Yield: 27%; ether. The allyl ethers were used without further purification transitions/°C: K 45 SA 72 Iso; dH(200 MHz, CDCl3, J/Hz) for the dihydroxylation reaction. 0.87 (t, J 6.4, 6H, CH3), 1.27–1.55 (m, 28H, CH2), 1.70–1.85 (m, 4H, OCH2CH2), 3.5–3.7 [m, 17H, OCH2, CH(OH)], 3.99 3.6.1. Procedure for the dihydroxylation. The appropriate (t, J 6.4, 4H, PhOCH2), 4.66 (s, 2H, PhCH2O), 6.90 (d, J 8.6, allyl ether (1 mmol, 657 mg) was added to a solution of N- 1H, H-Ar), 6.96 (d, J 8.6, 2H, H-Ar), 7.4–7.7 (m, 8H, H-Ar); methylmorpholine N-oxide (1.4 mmol, 0.15 ml of 60% aq.m/z (%) 778 ([M]+, 100). solution) in acetone (20 ml ). Osmium tetroxide (0.05 ml of 0.01 M solution in tert-butyl alcohol ) was added and the 8-{2-Decyloxy-5-[4-(4-decyloxyphenyl)phenyl]phenyl}-7- resulting mixture was stirred for 24 h at room temperature.oxaoctane-1,2-diol 35a. Synthesized from 4-(4-hydroxybutyl )- After this time starting materials could no longer be detected 2,2-dimethyl-1,3-dioxolane and 40. Eluent: chloroform–methand the mixture was worked up as follows: sodium hydrogen anol (1050.2). Yield: 37%; transitions/°C: K 75 SA 114 Iso; sulfite (4 ml saturated solution) was added and the resulting dH(200 MHz, CDCl3, J/Hz) 0.88 (t, J 6.6, 6H, CH3), 1.2–1.9 slurry was vigorously stirred at room temperature for 30 min.(m, 38H, CH2), 3.39 (dd, J 10.8, 7.6, 1H, CHAHBOH), 3.5–3.7 Afterwards, the solid were filtered oV, the residue was extracted [m, 4H, CHAHBOH, CH(OH), CH2O], 3.99 (t, J 6.6, 2H, three times with ethyl acetate (30 ml ) and the combined PhOCH2), 4.00 (t, J 6.5, 2H, PhOCH2), 4.59 (s, 2H, PhCH2O), organic phases were washed with 10% H2SO4, water and 6.90 (d, J 8.6, 1H, H-Ar), 6.96 (d, J 8.8, 2H, H-Ar), 7.47 (dd, brine.After drying with Na2SO4 the solvent was evaporated J 8.4, 2.4, 1H, H-Ar), 7.5–7.65 (m, 6H, H-Ar), 7.64 (d, 2.3, and the crude products were purified by column 1H, H-Ar); m/z (%) 688 ([M]+, 100).chromatography. 13-{2-Decyloxy-5-[4-(4-decyloxyphenyl)phenyl]phenyl}- 12-oxatridecane-1,2-diol 35b. Synthesized from 4-(9-hydroxy- 8-[2,5-Bis(4-decyloxyphenyl)phenyl]-4,7-dioxaoctane-1,2- nonyl )-2,2-dimethyl-1,3-dioxolane and 40. Crystallized from diol 29a. Synthesized from 2-allyloxyethanol and 37, followed light petroleum (60–80 °C).Yield: 17%; mp 110–112 °C; by dihydroxylation. Eluent: chloroform–methanol (1050.3). elemental analysis (%): found (calc. for C50H78O5): C, 78.87 Yield: 10%; transitions/°C: K 66 SA 73 Iso; dH(200 MHz, (79.11); H, 10.53 (10.36); dH(200 MHz, CDCl3, J/Hz) 0.89 CDCl3, J/Hz) 0.87 (t, J 6.7, 6H, CH3), 1.24–1.74 (m, 28H, (t, J 6.8, 6H, CH3), 1.29–1.40 (m, 44H, CH2), 1.74–1.85 (m, CH2), 1.76–1.83 (m, 4H, OCH2CH2), 3.5–3.7 (m, 8H, OCH2), 4H, OCH2CH2), 3.36–3.67 [m, 5H, CH(OH), OCH2], 4.01 3.7–3.9 [m, 1H, CH(OH)], 3.98 (t, J 6.5, 4H, PhOCH2), 4.49 (t, J 6.6, 2H, PhOCH2), 4.02 (t, J 6.5, 2H, PhOCH2), 4.61 (s, (s, 2H, PhCH2O), 6.93 (d, J 8.6, 2H, H-Ar), 6.96 (d, J 8.7, 2H, PhCH2O), 6.92 (d, J 8.6, 1H, H-Ar), 6.98 (d, J 8.8, 2H, 2H, H-Ar), 7.27–7.51 (m, 3H, H-Ar), 7.51 (d, J 8.8, 1H, H- H-Ar), 7.47–7.65 (m, 4H, H-Ar), 7.68 (d, 2.3, 1H, H-Ar); m/z Ar), 7.55 (d, J 8.7, 2H, H-Ar), 7.70 (d, J 1.7, 1H, H-Ar); m/z (%) 758 ([M]+, 18), 556 (100).(%) 690 ([M]+, 100). 3.5. Synthesis of the oligoethylene glycol ethers 30 8-{2-Decyloxy-5-[4-(4-decyloxyphenyl)phenyl]phenyl}-4,7- These compounds were obtained by etherification of dioxaoctane-1,2-diol 34a.Synthesized from 2-allyloxyethanol appropriate benzyl bromides with triethylene glycol and tetraand 40, followed by dihydroxylation. Eluent: chloroform– ethylene glycol respectively, according to procedure 3.4.1. methanol (1050.5). Yield: 30%; transitions/°C: K 58 SA 121 Iso; elemental analysis (%): found (calc. for C44H66O6): C, 11-[2,5-Bis(4-decyloxyphenyl)phenyl]-4,7,10- 76.20 (76.48); H, 9.89 (9.63); dH(200 MHz, CDCl3, J/Hz) trioxaundecanol 30a.Synthesized from triethylene glycol and 0.87 (t, J 6.6, 6H, CH3), 1.2–1.6 (m, 28H, CH2), 1.7–1.9 (m, 37. Eluent: chloroform–methanol (1050.1). Yield: 18%; 4H, OCH2CH2), 3.5–3.75 (m, 8H, OCH2), 3.8–3.9 [m, 1H, transitions/°C: K 61 (SA 52) Iso; dH(200 MHz, CDCl3, J/Hz) CH(OH)], 3.98 (t, J 6.6, 2H, PhOCH2), 4.00 (t, J 6.4, 2H, 0.87 (t, J 6.5, 6H, CH3), 1.26–1.55 (m, 28H, CH2), 1.72–1.86 PhOCH2), 4.66 (s, 2H, PhCH2O), 6.90 (d, J 8.4, 1H, H-Ar), (m, 4H, OCH2CH2), 3.53–3.69 (m, 12H, OCH2), 3.98 (t, J 6.96 (d, J 8.8, 2H, H-Ar), 7.4–7.6 (m, 7H, H-Ar), 7.65 (d, J 6.5, 4H, PhOCH2), 4.48 (s, 2H, PhCH2O), 6.93 (d, J 8.5, 2H, H-Ar), 6.95 (d, J 8.6, 2H, H-Ar), 7.30 (d, J 8.0, 2H, H-Ar), 2.2, 1H, H-Ar); m/z (%) 690 ([M]+, 100). 2618 J. Mater. Chem., 1998, 8, 2611–26263.7. 2,5-Bis(4-decyloxyphenyl )benzyl(triethyl )ammonium the yellowish oil obtained was crystallized from n-hexane. Yield: 92%; transitions/°C: K 58 (N 40) Iso; elemental analysis bromide 28 (%): found (calc. for C39H53O3Cl ): C, 77.45 (77.39); H, 8.57 In a three-necked flask equipped with a magnetic stirring bar (8.83); Cl, 5.64 (5.86); dH(200 MHz, CDCl3, J/Hz) 0.88 (t, J and a dropping funnel 37 (1.25 mmol, 800 mg) was dissolved 6.5, 6H, CH3), 1.26–1.41 (m, 28H, CH2), 1.67–1.78 (m, 4H, in dry acetonitrile (70 ml ) at 50 °C under argon atmosphere.OCH2CH2), 3.81 (t, J 6.4, 2H, PhOCH2), 4.00 (t, J 6.5, 2H, Dry triethylamine (30 ml ) was added dropwise while stirring. PhOCH2), 6.87 (d, J 8.5, 2H, H-Ar), 6.92 (d, J 8.5, 2H, HThe reaction mixture was stirred under reflux for 15 h.After Ar), 7.29 (d, J 8.5, 2H, H-Ar), 7.30–7.32 (m, 1H, H-Ar), 7.49 cooling to room temperature the solvent was evaporated and (dd, J 8.7, 1.7, 1H, H-Ar), 7.53 (d, J 8.6, 2H, H-Ar), 7.75 (d, the residue dissolved in chloroform (100 ml ). The organic J 1.2, 1H, H-Ar). phase was washed several times with water and dried with CaCl2.The solvent was removed in vacuo and the crude 3.11. Synthesis of the 2,5-bis(4-decyloxyphenyl )benzamides product obtained was purified by column chromatography 15–24 (Silica gel, chloroform–methanol 1052) followed by recrystallization from ethyl acetate. Yield: 35%; mp 140 °C; elemental In a three-necked flask equipped with a magnetic stirring bar analysis (%): found (calc.for C45H70O2NBr): C, 72.96 (73.34); the appropriate amine (1,5 mmol) was dissolved in dry DMF H, 9.26 (9.57); Br, 10.53 (10.84); N, 1.96 (1.90); dH(200 MHz, (30 ml ) under argon atmosphere. A solution of 26 (0.5 mmol, CDCl3, J/Hz) 0.86 (t, J 6.6, 6H, CH3), 1.14 (t, J 6.4, 9H, 300 mg) in toluene (20 ml ) was slowly added dropwise to this NCH2CH3), 1.18–1.57 (m, 28H, CH2), 1.7–1.9 (m, 4H, stirred mixture at room temperature.The mixture was stirred OCH2CH2CH2), 3.15–3.35 (m, 6H, NCH2CH3), 3.97 (t, J 6.5, several hours at 80 °C, until the reaction was complete 4H, PhOCH2), 4.94 (s, 2H, PhCH2N), 6.94 (d, J 8.5, 2H, H- (TLC). After the solvent was removed in vacuo the residue Ar), 6.99 (d, J 8.6, 2H, H-Ar), 7.21 (d, J 8.4, 2H, H-Ar), 7.35 was dissolved in diethyl ether (100 ml ) and the organic phase (d, J 8.0, 1H, H-Ar), 7.56 (d, J 8.5, 2H, H-Ar), 7.65 (d, J 8.7, was washed first with 10% hydrochloric acid (40 ml ) and 1H, H-Ar), 7.87 (s, 1H, H-Ar).afterwards with water (50 ml ). The organic phase was dried with sodium sulfate. Then the solvent was evaporated and the 3.8. Sodium 2,5-bis(4-decyloxyphenyl )benzoate 27 crude product obtained was purified by flash column chromatography followed by recrystallization. Methyl 2,5-bis(4-decyloxyphenyl )benzoate 14 (1 mmol, 601 mg) was added to a stirred solution prepared from ethanol 2,5-Bis(4-decyloxyphenyl)benzamide 15.Synthesized by (50 ml ) and NaOH (0.25 mol, 10 g) and heated 4 h under introduction of ammonia into a solution of 26 in DMF at reflux.After termination of the reaction the solvent was room temperature. Eluent: chloroform–methanol (1051). removed in vacuo and 50 ml water were added. The aqueous Crystallized from ethyl acetate. Yield: 65%; mp 184 °C; elemen- phase was extracted three times with chloroform (50 ml ). The tal analysis (%): found (calc. for C39H55O3N): C, 79.99 (79.95); combined organic phases were washed several times with water H, 9.21 (9.46); N, 2.04 (2.39); dH(500 MHz, CDCl3, J/Hz) and brine and afterwards dried with calcium chloride.After 0.87 (t, J 6.7, 6H, CH3), 1.2–1.5 (m, 28H, CH2), 1.75–1.84 evaporation of the solvent the residue was recrystallized from (m, 4H, OCH2CH2), 3.97 (t, J 6.8, 2H, PhOCH2), 3.99 (t, J ethyl acetate. Yield: 86%; mp 216–218 °C; elemental analysis 6.7, 2H, PhOCH2), 5.28 (br s, 1H, NH), 5.44 (br s, 1H, NH), (%): found (calc.for C39H53O4Na): C, 77.25 (76.94); H, 8.85 6.94 (d, J 8.6, 2H, H-Ar), 6.97 (d, J 8.5, 2H, H-Ar), 7.35 (d, (8.77); dH(200 MHz, CDCl3, J/Hz) 0.85 (t, J 6.4, 6H, CH3), J 7.8, 1H, H-Ar), 7.38 (d, J 8.8, 2H, H-Ar), 7.56 (d, J 8.8, 1.1–1.8 (m, 28H, CH2), 1.9–2.2 (m, 4H, OCH2CH2), 3.56 (t, 2H, H-Ar), 7.65 (dd, J 8.1, 2.1, 1H, H-Ar), 7.96 (d, J 2.0, 1H, J 6.3, 4H, PhOCH2), 6.55 (d, J 8.3, 2H, H-Ar), 6.75 (d, J 8.5, H-Ar); m/z (%) 585 ([M]+, 100). 2H, H-Ar), 7.1–7.2 (m, 3H, H-Ar), 7.4–7.5 (m, 3H, H-Ar), 7.91 (s, 1H, H-Ar). 2,5-Bis(4-decyloxyphenyl)benzoylaminoethane 16. Synthesized from ethylamine and 26. Eluent: chloroform– 3.9. 2,5-Bis(4-decyloxyphenyl )benzoic acid 25 methanol (1050.5).Crystallized from methanol. Yield: 84%; Compound 27 (10 mmol, 6.1 g) was dissolved in ethanol mp 111 °C; elemental analysis (%): found (calc. for (250 ml ). Concentrated hydrochloric acid (100 ml ) was added C41H59O3N): C, 79.98 (80.21); H, 9.37 (9.69); N, 2.04 (2.28); while stirring and the mixture was heated under reflux for 2 h. dH(500 MHz, CDCl3, J/Hz) 0.87 (t, J 7.1, 9H, CH3), 1.2–1.5 After cooling, water (250 ml ) was added dropwise and the (m, 28H, CH2), 1.75–1.83 (m, 4H, OCH2CH2), 3.21 (dq, 2H, mixture was extracted three times with diethyl ether (150 ml ).NHCH2), 3.96 (t, J 6.8, 2H, PhOCH2), 3.98 (t, J 6.7, 2H, The combined organic phases were washed several times with PhOCH2), 5.19 (t, J 5.6, 1H, NH), 6.93 (d, J 8.7, 2H, H-Ar), aq.NaHCO3 solution and then with water. After drying with 6.95 (d, J 8.7, 2H, H-Ar), 7.34 (d, J 8.8, 2H, H-Ar), 7.36 (d, Na2SO4 the solvent was removed in vacuo. The crude product J 8.7, 1H, H-Ar), 7.55 (d, J 8.7, 2H, H-Ar), 7.61 (dd, J 8.0, was purified by recrystallization from a mixture of n-hexane 2.0, 1H, H-Ar), 7.87 (d, J 1.9, 1H, H-Ar); m/z (%) 613 and ethyl acetate. Yield: 80%; transitions/°C: K 151 (SA 125) ([M]+, 100).Iso; elemental analysis (%): found (calc. for C39H54O4): C, 79.67 (79.82); H, 9.46 (9.27); dH(200 MHz, CDCl3, J/Hz) 2,5-Bis(4-decyloxyphenyl)benzohydrazide 17. Synthesized by 0.87 (t, J 6.5, 6H, CH3), 1.1–1.6 (m, 28H, CH2), 1.7–1.9 (m, adding hydrazine hydrate (100%) to a solution of 14 in n- 4H, OCH2CH2), 3.96 (t, J 6.5, 2H, PhOCH2), 3.99 (t, J 6.4, butanol and stirring at reflux temperature for 10 h.Crystallized 2H, PhOCH2), 6.90 (d, J 8.4, 2H, H-Ar), 6.96 (d, J 8.5, 2H, from ethanol. Yield: 83%; transitions/°C: K 98 SA 131 Iso; H-Ar), 7.29 (d, J 8.5, 2H, H-Ar), 7.38 (d, J 8.4, 1H, H-Ar), elemental analysis (%): found (calc. for C39H56O3N2): C, 77.78 7.55 (d, J 8.7, 2H, H-Ar), 7.69 (dd, J 8.6, 1.4, 1H, H-Ar), 8.09 (77.96); H, 9.76 (9.39); N, 4.91 (4.66); dH(500 MHz, CDCl3, (d, J 1.2, 1H, H-Ar); m/z (%) 586 ([M]+, 100).J/Hz) 0.87 (t, J 6.7, 6H, CH3), 1.22–1.51 (m, 28H, CH2), 1.75–1.83 (m, 4H, OCH2CH2), 3.8–4.0 (br s, 2H, NH2), 3.97 3.10. 2,5-Bis(4-decyloxyphenyl )benzoyl chloride 26 (t, J 6.8, 2H, PhOCH2), 3.99 (t, J 6.7, 2H, PhOCH2), 6.53 (br s, 1H, CONH), 6.93 (d, J 8.7, 2H, H-Ar), 6.96 (d, J 8.7, Oxalyl chloride (2.5 mmol, 460 mg) was added slowly with a syringe to a solution of 25 (0.25 mmol, 150 mg) in dry 2H, H-Ar), 7.31 (d, J 8.6, 2H, H-Ar), 7.38 (d, J 8.1, 1H, HAr), 7.54 (d, J 8.5, 2H, H-Ar), 7.64 (dd, J 8.1, 1.9, 1H, H- dichloromethane (10 ml ) under argon atmosphere at room temperature.The reaction mixture was stirred for one hour.Ar), 7.83 (d, J 2.0, 1H, H-Ar); m/z (%) 600 ([M]+, 8), 567 (26), 466 (100). The solvent and excess oxalyl chloride were evaporated and J. Mater. Chem., 1998, 8, 2611–2626 26192-[2,5-Bis(4-decyloxyphenyl)benzoylamino]ethanol 18. elemental analysis (%): found (calc. for C43H63O5N): C, 76.43 (76.63); H, 9.32 (9.42); N, 2.04 (2.08); dH(500 MHz, CDCl3, Synthesized from 2-aminoethanol and 26.Eluent: chloroform– methanol (1051). Crystallized from n-hexane–ethyl acetate. J/Hz) 0.87 (t, J 6.5, 6H, CH3), 1.21–1.50 (m, 28H, CH2), 1.74–1.83 (m, 4H, OCH2CH2), 2.8–3.9 (m, 8H, CH2N, CH2O), Yield: 87%; transitions/°C: K 118 SA 131 Iso; elemental analysis (%): found (calc. for C41H59O4N): C, 77.99 (78.18); 3.96 (t, J 6.7, 2H, PhOCH2), 3.98 (t, J 6.7, 2H, PhOCH2), 6.92 (d, J 8.8, 2H, H-Ar), 6.95 (d, J 8.7, 2H, H-Ar), 7.39 (d, H, 9.37 (9.44); N, 2.04 (2.22); dH(500 MHz, CDCl3, J/Hz) 0.87 (t, J 6.5, 6H, CH3), 1.23–1.50 (m, 28H, CH2), 1.77–1.82 J 8.7, 1H, H-Ar), 7.43 (d, J 8.7, 2H, H-Ar), 7.53 (d, J 8.8, 2H, H-Ar), 7.55 (d, J 1.8, 1H, H-Ar), 7.61 (dd, J 8.1, 1.8, 1H, (m, 4H, OCH2CH2), 3.26 (dt, J 10.2, 5.5, 2H, NHCH2), 3.50 (t, J 5.1, 2H, CH2OH), 3.97 (t, J 6.7, 2H, PhOCH2), 3.99 (t, H-Ar); m/z (%) 674 ([M+1]+, 100).J 6.7, 2H, PhOCH2), 5.68 (t, J 6.0, 1H, NH), 6.94 (dd, J 8.8, 2.1, 2H, H-Ar), 6.96 (2d, 4H, H-Ar), 7.37 (d, J 8.7, 3H, H- 4-[2,5-Bis(4-decyloxyphenyl)benzoyl]morpholine 23. Synthesized from morpholine and 26. Eluent: ethyl acetate. Ar), 7.55 (d, J 8.0, 2H, H-Ar), 7.63 (dd, J 8.0, 2.0, 1H, H-Ar), 7.86 (d, J 2.0, 1H, H-Ar); m/z (%) 629 ([M]+, 100).Crystallized from n-hexane–ethyl acetate. Yield: 81%; mp 96 °C; elemental analysis (%): found (calc. for C43H61O4N): C, 78.69 (78.74); H, 9.51 (9.37); N, 2.08 (2.14); dH(500 MHz, 3-[2,5-Bis(4-decyloxyphenyl)benzoylamino]propane-1,2-diol 19. Synthesized from 3-aminopropane-1,2-diol and 26. Eluent: CDCl3, J/Hz) 0.87 (t, J 6.5, 6H, CH3), 1.24–1.51 (m, 28H, CH2), 1.71–1.87 (m, 4H, OCH2CH2), 2.49–3.75 (m, 8H, ethyl acetate.Crystallized from n-hexane–ethyl acetate. Yield: 90%; transitions/°C: K 115 SA 142 Iso; elemental analysis (%): CH2N, CH2O), 3.99 (t, J 6.7, 4H, PhOCH2), 6.97 (2d, 4H, H-Ar), 7.40 (d, J 8.9, 2H, H-Ar), 7.5–7.7 (m, 5H, H-Ar); m/z found (calc. for C42H61O5N): C, 76.19 (76.43); H, 9.21 (9.32); N, 2.04 (2.12); dH(500 MHz, CDCl3, J/Hz) 0.87 (t, J 6.5, 6H, (%) 655 ([M]+, 80), 429 (27).CH3), 1.22–1.50 (m, 28H, CH2), 1.74–1.85 (m, 4H, OCH2CH2), 3.21–3.27 (m, 1H, NHCHAHB), 3.32–3.37 (m, 16-[2,5-Bis(4-decyloxyphenyl )benzoyl]-1,4,7,10,13- pentaoxa-16-azacyclooctadecane 24. Synthesized from 1H, NHCHAHB), 3.40 (dd, J 11,2, 4.8, 1H, CHAHBOH), 4.35 (dd, J 11,4, 4.5, 1H, CHAHBOH), 3.55–3.59 [m, 1H, CH(OH)], 1,4,7,10,13-pentaoxa-16-azacyclooctadecane and 26.Eluent: ethyl acetate. Crystallized from n-hexane. Yield: 72%; mp 3.97 (t, J 6.7, 2H, PhOCH2), 3.99 (t, J 6.7, 2H, PhOCH2), 5.72 (dd, J 6.0, 6.0, 1H, NH), 6.93 (d, J 8.5, 2H, H-Ar), 6.95 73 °C; elemental analysis (%): found (calc. for C51H77O8N): C, 73.29 (73.61); H, 9.57 (9.33); N, 1.61 (1.68); dH(200 MHz, (d, J 8.7, 2H, H-Ar), 7.33 (d, J 8.7, 2H, H-Ar), 7.35 (d, J 8.0, 1H, H-Ar), 7.54 (d, J 8.7, 2H, H-Ar), 7.63 (dd, J 8.0, 2.0, 1H, CDCl3, J/Hz) 0.86 (t, J 6.4, 6H, CH3), 1.24–1.56 (m, 28H, CH2), 1.69–1.85 (m, 4H, OCH2CH2), 3.1–3.8 (m, 24H, NCH2, H-Ar), 7.86 (d, J 2.0, 1H, H-Ar); dC(125 MHz, CDCl3) 14.11 (CH3), 22.68, 26.04, 29.24, 29.28, 29.32, 29.41, 29.56, 29.58, OCH2), 3.94 (t, J 6.7, 2H, PhOCH2), 3.98 (t, J 6.7, 2H, PhOCH2), 6.87 (d, J 8.7, 2H, H-Ar), 6.94 (d, J 8.8, 2H, H-Ar), 31.89 (CH2), 42.70 (NHCH2), 63.63 (CH2OH), 68.13 (PhOCH2), 68.23 (PhOCH2), 70.89 [CH(OH)CH2OH], 7.3–7.6 (m, 7H, H-Ar); m/z (%) 831 ([M]+, 100). 114.74, 114.91, 126.97, 128.01, 128.45, 129.92, 130.78, 131.84, 134.95, 137.31, 139.94, 159.12 (C-Ar), 171.58 (CO); m/z (%) 4. Results and discussion 659 ([M]+, 100). 4.1.Facial amphiphiles with lateral propane-2,3-diol groups N-[2,5-Bis(4-decyloxyphenyl )benzoyl]-1-deoxy-1- The glycerol ether 1e was the first compound investigated.27 methylamino-D-glucitol 20. Synthesized from 1-deoxy-1- It exhibits an enantiotropic smectic A phase. A comparison methylamino-D-glucitol and 26. Eluent: chloroform–methanol of the diol 1 with compound 227 carrying a lateral alkyl (1052).Crystallized from n-pentane. Yield: 90%; mp 87 °C; substituent of comparable size (Fig. 2) indicates a significant elemental analysis (%): found (calc. for C46H69O8N): C, 71.98 mesophase stabilizing influence of the two hydroxy groups. (72.31); H, 9.37 (9.10); N, 1.74 (1.83); [a]D30 0.9 (c 1.05, Furthermore, it is obvious that the laterally attached hydrogen CHCl3); dH(500 MHz, CDCl3, J/Hz) 0.86 (t, J 6.1, 6H, CH3), bonding group increases the structural order, which means 1.21–1.48 (m, 28H, CH2), 1.71–1.82 (m, 4H, OCH2CH2), 2.47 that the layered smectic A phase is stabilized with respect to (s, 3H, NCH3), 3.2–4.95 [m, 8H, CH(OH), CH2O, CH2N], the nematic phase of the nonamphiphilic compound 2. 3.94 (t, J 6.7, 2H, PhOCH2), 3.96 (t, J 6.7, 2H, PhOCH2), Contrary to smectic phases of conventional amphiphiles and 6.93 (2d, 4H, H-Ar), 7.33 (d, J 8.6, 2H, H-Ar), 7.38 (d, J 8.1, 1H, H-Ar), 7.51 (d, J 8.6, 3H, H-Ar), 7.59 (dd, J 8.2, 1.8, 1H, H-Ar); m/z (%) 763 ([M]+, 18), 599 (28), 586 (23), 569 (100). 1-[2,5-Bis(4-decyloxyphenyl)benzoylamino]-1-deoxy-Dglucitol 21. Synthesized from 1-amino-1-deoxy-D-glucitol and 26.Eluent: chloroform–methanol (1052). Crystallized from nhexane –ethyl acetate. Yield: 76%; transitions/°C: K 112 SA 147 Iso; elemental analysis (%): found (calc. for C45H67O8N): C, 71.71 (72.06); H, 9.22 (9.00); N, 1.59 (1.87); [a]D25 -0.1 (c 1.09, CHCl3); dH(200 MHz, DMSO, J/Hz) 0.87 (t, J 6.5, 6H, CH3), 1.21–1.52 (m, 28H, CH2), 1.74–1.83 (m, 4H, OCH2CH2), 3.2–3.7 [m, 8H, CH(OH), CH2O, CH2N], 3.98 (t, J 6.7, 2H, PhOCH2), 3.99 (t, J 6.7, 2H, PhOCH2), 4.1–4.4 (m, 3H, OH), 4.48 (d, J 4.7, 1H, OH), 4.77 (d, J 4.5, 1H, OH), 6.93 (d, J 8.7, 2H, H-Ar), 6.99 (d, J 8.8, 2H, H-Ar), 7.34 (d, J 8.6, 2H, H-Ar), 7.38 (d, J 8.1, 1H, H-Ar), 7.62 (m, Fig. 2 Comparison of the mesomorphic properties of the laterally substituted compounds 1e and 2.27 The existence regions of the phases 4H, H-Ar), 8.19 (dd, J 5.4, 5.4, 1H, NH); m/z (%) 749 ([M]+, are displayed as bars.Black areas indicate the solid crystalline state 68), 627 (21), 586 (83), 569 (100). and hatched or blank areas correspond to liquid crystalline phases. If the liquid crystalline phase appears below the melting point, these are 3-[2,5-Bis(4-decyloxyphenyl)benzoyl]-3-azapentane-1,5-diol monotropic (metastable) mesophases which are given in brackets.The 22. Synthesized from diethanolamine and 26. Eluent: numbers above the bars indicate the phase transition temperatures. chloroform–methanol (1051). Crystallized from n-hexane– Abbreviations: K=crystalline solid, N=nematic Phase, SA=smectic A phase. ethyl acetate. Yield: 70%; transitions/°C: K 110 (SA 97) Iso; 2620 J.Mater. Chem., 1998, 8, 2611–2626amphiphiles containing terminally connected rigid units, which usually form bilayer structures, the smectic phase of 1e presents a monolayer structure. The fixation of the molecules in the single-layers should be provided by attractive hydrogen bonding28 between their hydroxy groups and probably also by hydrogen bonding between the hydroxy groups and the aromatic p-systems.Furthermore, the hydroxy groups signifi- cantly increase the polarity in the region of the rigid cores and thus favor micro-segregation of these regions from the lipophilic alkyl chains.29 Thus, the smectic layer structure is stabilized by the attractive forces provided by hydrogen bonding and by micro-segregation. The propane-2,3-diol group incorporates a stereogenic center.Remarkably, however, no measurable influence of chirality on the mesomorphic properties has been found. Both the racemic compound 1e and the optically active compound (S)-1e (K 83 SA 114 Iso) have identical melting and clearing temperatures. Therefore all other compounds described in this paper have been prepared only as racemic mixtures. The dependence of the mesomorphic properties on the length of the terminal chains is shown in Fig. 3. With the exception of the nematic ethoxy substituted compound 1a all other synthesized p-terphenyl derivatives 1 display smectic A phases. Remarkably, the mesophase stability significantly increases on elongation of the terminal lipophilic chains. Also the quinquaphenyl derivative 5 and the biphenyl derivative 6 exhibit SA phases.The corresponding methyl substituted biphenyl derivative 8, carrying the much smaller methyl group, exhibits a monotropic nematic phase with a significantly lower clearing temperature than the SA phase of 6. This again shows the stabilizing influence of the lateral diol group. However, compound 7, incorporating only a single benzene ring, is a non-mesomorphic compound.This shows that the amphiphilic structure alone does not cause the liquid crystallinity in this class of compounds. Mesomorphic properties are also lost if the linear p-terphenyl rigid core is replaced by an angular m-terphenyl central unit (compound 4). This is in accordance with the behavior of conventional calamitic liquid crystals. The mesophase destabilization on replacing the alkoxy substituents by alkyl groups (compounds 3) is also analogous to nonamphiphilic calamitic mesogens. 4.2. Influence of the position of the diol group In Fig. 4 the dependence of the mesomorphic properties on the position of the 4,5-dihydroxy-2-oxapentyl group is compared with the influence of a methyl group in the same positions. For the diol derivatives 1e, 11 and 13 the order of mesophase stability (1e~11<13) is principally the same as for the methyl substituted molecules (915~1018<1218).However, the SC phases of the methyl substituted derivatives are completely replaced by smectic A phases. Furthermore it seems that the mesophase stabilizing eVect of the lateral diol group is largest for the centrally substituted compound 1e and it decreases on migration of the lateral group to the terminal end of the rigid core.Thus, a mesophase stabilization in comparison with the corresponding methyl substituted compounds is observed only for the 2¾-substituted compound, whereas the clearing temperature of the diol 13 with its polar group in the 3-position is significantly lower than that of the corresponding 3-methyl derivative 12.Probably two diVerent reasons are responsible for this eVect. At first the mesophase Fig. 3 Mesomorphic properties of the compounds 1 as a function of the length of the terminal chains. destabilizing influence of lateral substituents depends on their J. Mater. Chem., 1998, 8, 2611–2626 2621Fig. 4 Influence of the position of the lateral groups on the liquid crystalline behavior.position at the rigid core. Those in central positions have a more pronounced destabilizing influence than those in more peripheral positions.1–3,5,18 The reason may be that the lateral Fig. 5 Properties of 4,4>-didecyloxyterphenyl derivatives with lateral substituents in a central position are forced to be located amide groups. between the rigid p-terphenyl cores, whereas those in a peripheral position can be expelled more easily into the region of the flexible terminal alkyl chains.This would be more favorable bonding is larger than the mesophase destabilizing eVect due for lipophilic substituents, like the methyl group, than for to unfavorable steric interactions from increasing the size of polar hydrophilic substituents which are incompatible with the the substituents by additional CH2OH groups.It is especially alkyl groups. This second eVect could be responsible for the remarkable that the acylated aminosugar 2027 exhibits the destabilization of the smectic layers of the 3-substituted diol most stable smectic phase of all compounds compared in derivative 13 with respect to the methyl substituted Fig. 5. This compound represents an entirely new type of compound 12. mesogenic carbohydrate derivative, which combines a rigid Remarkably, for all diol substituted compounds, no SC rod-like core laterally connected with a polyhydroxy unit. It phase was found even on supercooling the samples. It should seems, however, that this class of compounds is very sensitive be mentioned here that this phenomenon is often observed in to slight changes of the molecular structure.The N-methyl systems of calamitic molecules with strong attractive forces amide 21, for example, in which the NH group of 20 is between their rigid cores, especially in donor–acceptor replaced by a NCH3 group, is a non-mesogenic solid. It seems systems.30 For example, SA phases can be exclusively induced that the NH group plays an important role as a proton donor in mixed systems of calamitic molecules with donor and group in the mesophase stabilization of this class of comacceptor properties30 and in mixed systems consisting of pounds.Likewise, comparison of the ether 1e with the related calamitic mesogens and TNF.31 Steric eVects should also amide 19 reveals a mesophase stabilization of 28 K following contribute to the loss of SC phases. The large lateral substitu- replacement of the CH2O group by a CONH group. However, ents disfavor tilting, because this would further enlarge the the mesophase destabilization on introduction of the N-methyl lateral cross-section and additionally disturb the packing of the alkyl chains. 4.3. Variation of the lateral groups A wide variety of diVerent polar groups has been checked.In Fig. 5 the molecules with lateral amide groups are compared with the methyl carboxylate 1415,27 which has exclusively a nematic phase. The amide 15 and the N-ethyl amide 16 are high melting crystalline solids which rapidly crystallize on cooling. Therefore no liquid crystalline phases can be observed. However if one additional proton donating functional group (OH or NH2) is introduced into the lateral group, then liquid crystalline properties can be found.Both the hydrazide 17 and the 2-hydroxyethylamide 18 form SA phases with significantly higher mesophase stability than the ester compound 14.27 Furthermore, with an increasing number of hydroxy groups in the lateral chain the mesophase stability of the SA phase rises (compounds 18, 19 and 20 in Fig. 5). Remarkably, the mesophase stability increases despite the fact that the lateral groups are enlarged simultaneously. This means that the Fig. 6 Comparison of the mesomorphic properties of the amides 22, 23 and 24. mesophase stabilization provided by the additional hydrogen 2622 J. Mater. Chem., 1998, 8, 2611–2626Fig. 8 Influence of the length of the lateral polyether chain on the mesomorphic properties of 2¾-substituted 4,4>-didecyloxyterphenyl derivatives12 (Colr=rectangular columnar mesophase).Fig. 7 Comparison of the phase transition temperatures of the carboxylic acid 25,27 the corresponding acid chloride 2627 and the sodium carboxylate 27. group is much larger. Therefore, the complete loss of mesogenic properties for compound 21 could not be explained by the diminished degree of hydrogen bonding alone.Changes in the molecular conformation can probably also contribute to this eVect. Compounds with polar lateral groups without the possibility of forming hydrogen bonds are in most cases non-mesomorphic. This is obvious from a comparison of the diol 22 with the morpholide 23, which is the cyclic analogue of the diol 22 without hydroxy groups (Fig. 6). The azacrown compound 24 is also a crystalline solid. Intermolecular hydrogen bonding is also important in carboxylic acids which are known to form dimers.32 In Fig. 7 the carboxylic acid 2527 is compared with its acid chloride 26.27 Again the carboxylic acid 25, i.e. the compound which is able Fig. 9 Optical photomicrograph of the texture of compound 29b to form hydrogen bonding, displays the higher mesophase between crossed polarizers at 40 °C.The Colr phase (spherulitic texture at the left hand side) is growing out of the homeotropically aligned domains of the SA phase while cooling. Small regions of the homeotropically aligned SA phase with some oily streaks can still be seen at the right-hand side.stability. The ionic amphiphiles, the carboxylate 27 (Fig. 7) as well as the quaternary ammonium salt 28 are high melting solids without detectable thermotropic liquid crystalline properties. 4.4. Polyether amphiphiles In order to further clarify the relation between molecular structure and liquid crystalline behavior we have decoupled the lateral rac-propane-2,3-diol unit from the rigid p-terphenyl core via hydrophilic polyether chains.12 The phase transition temperatures of these compounds are collected in Fig. 8. The clearing temperatures as well as the melting temperatures decrease significantly with increasing length of the oligo- (oxyethylene) spacer which connects the propane-2,3-diol group to the rigid core. The clearing temperatures are more depressed per spacer length increment than the melting temperatures.This results in monotropic mesophases for compounds 29b and 29c with longer oligo(oxyethylene) spacers. However they can easily be supercooled. The diol 1e and the ethylene glycol derivative 29a form a smectic A phase as the Fig. 10 Schematic illustration of the SA phase and a possible ribbon only mesophase.On cooling of compound 29b a transition arrangement for the rectangular columnar phases (Colr) of compounds from the SA phase to a columnar mesophase occurs at 40 °C. 29b and 29c.12 The black areas represent the phase separated regions As shown in Fig. 9 the transition to the columnar phase can of the polar groups. The polar groups of the molecules in the middle be seen in the polarizing microscope by the formation of a of the ribbons cross over the neighboring calamitic terphenyl units. spherulitic texture in the homeotropically aligned SA phase.J. Mater. Chem., 1998, 8, 2611–2626 2623of these layers. The ribbons should consist of parallel rigid pterphenyl cores laterally separated by the hydrophilic domains of the lateral groups. The alkyl chains are molten and fill up the space between the ribbons in the other dimension.From the obtained lattice parameter it was calculated that between four and five molecules should be arranged in the cross-section of the ribbons.12 Therefore, the polar lateral groups of the molecules in the middle of these ribbons must cross over the neighboring calamitic terphenyl units in order to become incorporated into the polar regions.In Fig. 11 the CPK models of four molecules of the tris(oxyethylene) derivative 29c are placed side by side as they would be arranged in the crosssection of the ribbons. It shows that indeed the lateral groups of the molecules in the middle are suYciently long to reach the polar regions. Therefore, we propose that, in addition to a certain polarity and size, a suYcient length of the polar groups is also an important prerequisite for columnar mesophase formation in this class of compounds.Fig. 11 CPK model showing a possible arrangement of the molecules The proposed ribbon model seems reasonable, because it 29c in the cross-section of a ribbon. enables the segregation of polar and lipophilic units into separate regions whereby the parallel organization of the rodlike molecules is maintained.In respect of the local order within the ribbons, the columnar phase can be regarded as a modulated smectic phase, but in comparison to most other modulated phases the lateral diameter of the ribbons is rather small. Alternatively, this ribbon structure can be described as an alternating structure of two types of lamellae.One type consists of alkyl chains and the second type is composed of ribbons of rigid p-terphenyl units laterally separated by cylinders containing the hydrophilic groups [see Fig. 12(a)]. This model is related to that suggested for supermolecular structures which have recently been found in triblock copolymers consisting of three linearly combined flexible blocks [see Fig. 12 Schematic representation of the lamellae-cylinder structures Fig. 12(b)].33 Here, beside other superstructures, lamellae with of (a) the Colr phases of compounds 29b and 29c and (b) of a cylinders at the lamella interfaces have been found.34 Indeed, microphase segregated linear ABC triblock copolymers.33,34 the molecules described here can be regarded as low molecular weight three-block compounds composed of three diVerent and incompatible blocks: the rigid cores, the flexible and From the X-ray diVraction pattern and taking into account lipophilic alkyl chains and the flexible but polar polyether the molecular dimensions a rectangular columnar structure chains.In contrast to linear triblock copolymers, the Y-shaped was suggested for this mesophase.12 Compound 29c with a block molecules described here have the cylinders located longer polyether chain exhibits exclusively the (monotropic) within one of the distinct layers instead of being located at rectangular columnar mesophase (Colr).For these columnar their interface. There are at least two reasons for their position phases a ribbon structure as shown in Fig. 10 was proposed.12 within the layer of the rigid cores. At first, this organization According to this model, the flexible and polar polyether is provided by the fixation of the polar groups in a central chains should segregate from the rigid cores into separate lateral position. Additionally, the rigidity of central rod-like domains and thus give rise to a collapse of the smectic layers into ribbons which can be regarded as small band like segments block reduces the number of possible conformations and thus Fig. 13 Influence of the structure of the lateral group on the mesomorphic properties of the 2¾-substituted p-terphenyl derivatives (M=unknown mesophase with schlieren texture). 2624 J. Mater. Chem., 1998, 8, 2611–2626the rigid cores, and also a certain polarity of the lateral substituents (polyether chains instead of alkyl chains), are both necessary for the occurrence of columnar mesophases. 4.5. Crown ether derivatives The crown compounds 33a–c36 (Fig. 14) represent closed analogues of compounds 29 and 30. Because of the absence of proton donor groups they lack the possibility of hydrogen bonding. As mentioned in the introduction, such large lateral groups usually suppress smectic phases and give rise to nematic phases.Also the laterally alkyl-substituted terphenyl derivatives 2 (see Fig. 2) and 32 (Fig. 13) have exclusively nematic phases. No smectic phase can be observed on cooling compound 32 until crystallization sets in at 15 °C. The crown compounds 33, however, have an SA–N dimorphism in contrast to the alkyl substituted compounds 2 and 32.This means that layer structures are preferred by these polyethers. Probably the polar crown ether groups can force micro-segregation between the central regions consisting of the rigid cores and the crown ether units from the terminal lipophilic alkyl chains. Fig. 14 Influence of the size of laterally attached crown units on the Thus, in the crown compounds the steric disturbance of the mesomorphic properties of the facial amphiphiles.lateral groups is in competition with the layer stabilizing eVect provided by micro-segregation.37 inhibits the organization of the molecules in a conventional inverted hexagonal columnar mesophase as known for flexible 4.6. Influence of the position of the polyether chain double chain amphiphiles and taper shaped molecules.35 In order to further evaluate the structural requirements As mentioned above the 3-substituted diol 13 has a significantly higher smectic mesophase stability than the corresponding 2¾- which are responsible for the occurrence of columnar mesophases, compound 32 with a lateral alkyl chain, compound 31 substituted molecule 1e (see Fig. 4). Also the 3-substituted polyether compounds 34 (Fig. 15) have enhanced clearing with a 1,2-diol unit coupled via a hydrophobic alkyl spacer, and two oligo(oxyethylene) ethers without diol units (com- temperatures in comparison to the 2¾-substituted analogues 29 (Fig. 8). Remarkably however, only SA phases and no colum- pounds 30) were investigated. As shown in Fig. 13 the columnar phase is replaced by a smectic A phase if one of the nar mesophases could be detected for the diols 34b and 34c with long polyether chains in the peripheral 3-position at the hydroxy groups in the polar group is removed (compounds 30).A nematic phase is found if the polyether chain is replaced rigid core. It seems that the formation of columnar mesophases is bound to a very special molecular structure and it is favored by a lipophilic alkyl chain (compound 32).If a diol group is attached to the end of the lateral alkyl group (compound 31) by a central attachment of the polar group. Also in the series of 3-substituted compounds the polyether a monotropic mesophase with a schlieren texture is observed. Because compound 31 rapidly crystallizes we were not able to chains were replaced by alkyl chains (see Fig. 15). Compound 35a in which one ether oxygen in the lateral chain of 34a is diVerentiate between an SC phase and a nematic phase. Nevertheless, these structural variations show that a suYcient replaced by a CH2 group has a slightly decreased mesophase stability. No mesomorphic properties can be found for com- number of hydrogen bonding sites (diols vs. simple alcohols) providing suYciently strong attractive interactions between pound 35b in which the diol group is decoupled by a long Fig. 15 Influence of the structure of the lateral group on the mesomorphic properties of 3-substituted 2,2>-didecyloxyterphenyl derivatives. J. Mater. Chem., 1998, 8, 2611–2626 262514 (a) N. Miyaura, K. Yamada and A. Suzuki, Tetrahedron Lett., alkyl spacer.This could be due to the poor supercoolability 1979, 3437; (b)M. Hird, G. W. Gray and K. J. Toyne, Mol. Cryst. of this compound (85 °C). Liq. Cryst. Lett., 1991, 206, 187; (c) M. Hird, G. W. Gray and K. J. Toyne, Liq. Cryst., 1994, 16, 625. 15 J. Andersch and C. Tschierske, Liq. Cryst., 1996, 31, 51. 5. Conclusions 16 C. D. Hurd and M. A. Pollack, J. Am. Chem. Soc., 1938, 60, 1908.The investigations have shown that—depending on the 17 V. van Rheenen, R. C. Kelley and D. F. Cha, Tetrahedron Lett., 1976, 1973. molecular structure—facial amphiphiles can form monolayer 18 J. Andersch, C. Tschierske, S. Diele and D. Lose, J. Mater. Chem., SA phases and columnar mesophases. Micro-segregation and 1996, 6, 1297. cohesive forces provided by hydrogen bonding stabilize a 19 Obtained by NBS bromination of 5-decyloxy-2-(4-decyloxy- parallel layer-like arrangement of the calamitic molecules.If phenyl )toluene, which was prepared by Suzuki coupling of 2- the polar groups are hydrogen bonding functional groups, bromo-5-decyloxytoluene with 1 equiv. of 4-decyloxyphenyltheir mesophase stability can be higher than that of related boronic acid analogous to the synthesis of 39 (Scheme 4) (ref. 18). 20 Obtained by NBS bromination of 3,5-bis(4-decyloxyphenyl )tolu- compounds with smaller lateral substituents. However, the ene, which was prepared by Suzuki coupling of 3,5-dibromotolu- stabilization of layered mesophases is in competition with the ene with 2 equiv. of 4-decyloxyphenylboronic acid, analogous to disturbance provided by the space filling of these substituents.the synthesis of 2,5-bis(4-decyloxyphenyl )benzyl bromide Furthermore, in many cases (e.g. ionic amphiphiles) the high (ref. 15). melting temperatures and the poor supercoolability of the 21 R. Adams and L. H. Ulich, J. Am. Chem. Soc., 1920, 42, 599. materials prevents potential (monotropic) mesophases from 22 R. Plehnert, J. A. Schro� ter and C.Tschierske, Langmuir, 1998, 14, 5245. being observed. 23 J. Goerdeler, Houben-Weyl, Methoden der Organischen Chemie, In cases of compounds with rather large, flexible and polar Georg Thieme Verlag, Stuttgart, 1958, vol. 11/2, p. 591. lateral substituents fixed to the center of the rigid terphenyl 24 M. Hird, A. J. Seed, K. J. Toyne, J. W. Goodby, G. W. Gray and unit (compounds 29b and 29c, see Fig. 8) columnar mesophases D. G. McDonnell, J. Mater. Chem., 1993, 3, 851. can be found. These columnar phases should represent ribbon 25 F. Hentrich, C. Tschierske, S. Diele and C. Sauer, J. Mater. phases resulting from the collapse of the smectic layers. The Chem., 1994, 4, 1547. 26 D. Landini, F. Montanari and F. Rolla, Synthesis, 1979, 134. lateral polyether chains are incompatible with the rigid and 27 F.Hildebrandt, J. A. Schro� ter, C. Tschierske, R. Festag, lipophilic p-terphenyl units and segregate from them into R. Kleppinger and J. H.WendorV, Angew. Chem., 1995, 107, 1780; separate cylindrical domains which interrupt the smectic layers. Angew. Chem., Int. Ed. Engl., 1995, 34, 1631. These molecules can be regarded as block molecules composed 28 Although the mesophase stabilization by hydrogen bonding is well of three diVerent and incompatible molecular parts.It could documented for calamitic molecules with terminal hydrogen bondbe expected that the design of novel types of low molecular ing (ref. 10, 32) and for taper-shaped polyhydroxy compounds [ref. 35(c),(d)], the mesophase stabilization by a laterally attached weight block compounds consisting of three or even more diol group is rather surprising. The formation of an SA phase for a diVerent and incompatible molecular parts connected via compound with laterally attached hydroxy groups was only diVerent topologies might provide interesting new liquid reported for some inositol ethers (K.Praefcke and D. Blunk, Liq. crystalline materials.37,38 Cryst., 1993, 14, 1181; K.Praefcke, D. Blunk and J. Hempel, Mol. Finally, it should be mentioned that all compounds with Cryst. Liq. Cryst., 1994, 243, 323.) hydrophilic lateral groups can form lyotropic mesoph as 29 C. Tschierske, J. Mater. Chem., 1998, 8, 1485. 30 (a) K. Praefcke and D. Singer, in Handbook of Liquid Crystals, ed. will be reported in a separate paper.13 D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess and V. Vill, Wiley-VCH, Weinheim, 1998, vol. 2b, p. 945; (b) R. Dabrowski Acknowledgments and K. Czuprynski, in Modern Topics in Liquid Crystals, ed. A. Buka, World Scientific, 1993, p. 124. This work was supported by the Deutsche 31 (a) B. Neumann, D. Joachimi and C. Tschierske, Liq. Cryst., 1997, Forschungsgemeinschaft and the Fonds der Chemischen 22, 509; (b) R. Lunkwitz, B. Neumann and C. Tschierske, Liq. Cryst., 1998, 25, 403. Industrie. 32 C. M. Paleos and D. Tsiourvas, Angew. Chem., 1995, 107, 1839. 33 W. Zheng and Z.-G.Wang, Macromolecules, 1995, 28, 7215. 6. References 34 C. Auschra and R. Stadler, Macromolecules, 1993, 26, 2171. 35 (a) A. Eckert, B. Kohne and K. Praefcke, Z. 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