摘要:

AbstractThe properties of the tetraazamacrocyclic compoundN,N′‐dimethyl‐2,11‐diaza[3,3](2,6)pyridinophane (L‐N4Me2) as a ligand for some selected metal chlorides have been examined. The crystal structure of the uncoordinated ligand reveals asynchair‐chair conformation. In solution, the ligand displays fluctional behavior. Reaction of L‐N4Me2with the chlorides of copper(II), nickel(II), and cobalt(II) affords the complexes [Cu(L‐N4Me2)Cl2] · H2O (3), [Ni(L‐N4Me2)(H2O)Cl]Cl · H2O (4), and [Co(L‐N4Me2)Cl2] · 2 H2O (5) in which the ligand adopts asynboat‐boat conformation. The crystal structures of4and5are presented. Due to the small cavity of the 12‐membered ring of the ligand, exclusively distortedcis‐octahedral coordination geometries are found at the metal sites. A comparison of structural data of several complexes with this ligand shows that the extent of the distortions from ideal octahedral geometry is mainly determined by the M‐Npybond strength. The electronic as well as the solution properties of the described complexes have been investigated by electronic absorption spectroscopy. ESR spectroscop

ISSN:0009-2940    

DOI:10.1002/cber.19951280602

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractNine dipeptides and one tripeptide containing histidine were converted into analytically pure zinc complexes. Four different compositions were observed. The peptides used as or converted into the monoacids LH (HisGly, GlyHis, HisPhe, HisHis) form the compounds ZnL2(11a, 12–14) and alternatively (HisGly, HisGlyGly) the compounds ZnL(BF4) (11b, 20). The peptides used as amides (HisGlyNH2, HisMetNH2) act as neutral ligands in the compounds ZnL2(ClO4)2(15, 16). The three remaining peptides (HisAsp, AlaHis, β‐AlaHis) behave like diprotonic acids LH2forming the compounds ZnL (17–19). Spectra and solubilities indicate that complexes11a, 13, 15, and16are mononuclear containing two chelating peptides bound by their amino and imidazole nitrogen atoms. All other complexes seem to be coordination polymers in some of which the amide N and O atoms are involved in the coordination. This was proven by a structure determination for Zn(GlyHis)2(12) in which the zinc ions are coordinated octahedrally by two histidine N, two amino N, and two amide O atoms of four peptide re

ISSN:0009-2940    

DOI:10.1002/cber.19951280603

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe solvation and ion pair nature of α‐(phenylthio)benzyllithium (2d) in THF solution were investigated by NMR‐spectroscopic methods. The effect of additives such as diethylene‐glycol dimethyl ether or of 12‐crown‐4 was studied. The results were compared to those of benzyllithium compounds4and6, containing a pentaoxapentadecane ansa chain. These compounds exist as contact ion pairs in which lithium is held at the anionic carbon. This is reflected in the6Li,13C coupling and1H,6Li‐HOESY contacts in the

ISSN:0009-2940    

DOI:10.1002/cber.19951280604

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractPhotolysis or thermolysis of Cp*Ir(CO)2(1) in the presence of excess sulfur (S8) gives Cp*Ir(CO)(S4) (2a) which is further decarbonylated to [Cp*Ir(μ‐S4)]2(4a). The analogous reaction of1with excess selenium leads to Cp*2Ir2(μ‐Se)(μ‐Se4) (6b). In the case of limited chalcogen supply, the products are [Cp*Ir(CO)(μ‐E)]2[E = S (3a), Se3b)] and [Cp*Ir(μ‐E)]4[E = S (5a), Se (5b)]. A stepwise formation of the pseudocubane clusters5a,bfrom dinuclear precursors is assumed. The solid‐state structure of2ahas been determined by X‐r

ISSN:0009-2940    

DOI:10.1002/cber.19951280605

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe tetrathiaoxalate complex Cp4Ti2C2S4(1) reacts with an equimolar amount of COCl2to give the blue‐green mononuclear complex Cp2TiC2S4CO (4). This reaction is analogous to the known reactions of1with SCl2or S2Cl2. However, when1was treated with equimolar amounts of the bifunctional sulfenyl chlorides 1,2‐C2H4(SCl)2(5), 1,3‐C3H6(SCl)2(6) or 1,2‐C6H4(SCl)2(7), the bi‐ or monocyclic tetrakisdisulfanes C6H8S8(9b), C8H12S8(10), and C14H8S8(11), respectively, were obtained. The X‐ray crystal structure analysis of11· CS2showed that11possessesCisymmetry with a central exocyclic CC double bond similar to tetrathiafulvalenes: C6H4(μ‐S2)

ISSN:0009-2940    

DOI:10.1002/cber.19951280606

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractTris(dimethylphenylsilyl)antimony (1) was prepared in moderate yield from dimetallic “Na3Sb” (generated in situ) and chlorodimethylphenylsilane in tetrahydrofuran at reflux temperature. The product was identified by standard analytical and spectroscopic techniques, and the crystal structure was determined by single‐crystal X‐ray diffraction (triclinic, space groupP1,Z= 2). The SbSi3skeleton is pyramidal (average Si‐Sb‐Si angle 100.2°, average Sb‐Si bond length 2.558 Å), and the Me2PhSi groups are in a stagger

ISSN:0009-2940    

DOI:10.1002/cber.19951280607

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractTa4FeTe4has been synthesized and its structure determined by single‐crystal X‐ray methods. It crystallizes in the ortho‐rhombic space group Pbam with Z = 4 anda= 10.514(5),b= 18.275(7), andc= 4.815(1) Å. Ta4FeTe4has a chain structure built up by Fe‐centered Ta8‐square antiprisms sharing common square faces. The resistivity of Ta4FeTe4has been measured by a two‐point method. Ta4FeTe4shows metallic behavior. The structure of Ta4FeTe4is discussed in relation to other early transition metal cluster compounds. A rational approach to the synthesis of related compounds

ISSN:0009-2940    

DOI:10.1002/cber.19951280608

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA mild and effective method for the preparation of a variety of aromatic, olefinic, and acetylenic sodium sulfonates is described. The reaction of trialkylaryl‐ (2a‐k) and ‐heteroarylstannanes (4a‐d), bis‐(1‐alkenyl)dibutylstannanes (6a‐f), or trialkylalkynylsta manes with trimethylsilyl chlorosulfonate (1) followed by hydrolysis with aqueous NaHCO3provides the sodium sulfonates in anipso‐specific and in the case of vinylic stannanes stereospecific manner. A comparison of the reactivity of stannylated and silylated olefinic compounds13and14underlines the greater leaving ability of the stannyl moiety. The in situ preparation of the stannanes makes it possible to apply the synthetic method to natural products such asN‐substitute

ISSN:0009-2940    

DOI:10.1002/cber.19951280609

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe [3 + 2] cyclocondensation of 2‐amino‐1,3‐thiazoline, 2‐aminopyridines, 2‐ and 4‐aminopyrimidines, 2‐aminopyrazine, and 2‐aminoquinoline with chloromethyldichlorophosphane in the presence of triethylamine yields regiospecifically 5,6‐dihydrothiazolo[2,3‐e][1,4,2]diazaphosphole (3), 1,4,2‐diazaphospholo[4,5‐α]pyridines (12), 1,4,2‐diazaphospholo[4,5‐α]pyrimidines (15), 1,4,2‐diazaphospholo[4,5‐e]pyrimidine (17), 1,4,2‐diazaphospholo[4,5‐α]pyrazine (19), and [1,4,2]diazaphospholo[4,5‐α]quinoline (22), respectively. Using 2‐amino‐1,3‐thiazole (4) and 2‐aminobenzothiazoles8, we obtained mixtures of the 1,5‐ and 4,5‐anellated 1,4,2‐diazaphospholes5/6, 9a/10aand9b/10b, while in the case of the methyl derivative8conly the [1,4,2]diazaphospholo[5,4‐b][1,3]benzothiazole10cwas formed. In the reaction of 2‐aminothiazole and 2‐aminopyrazine with Chloromethyldichlorophosphane the bis(diazaphospholo)‐substituted chloromethylphosphanes7and20could be detected. The new anellated 1,4,2‐diazaphospholes a

ISSN:0009-2940    

DOI:10.1002/cber.19951280610

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractAttempts to prepare various peripheral tetra‐ and octasubstituted (phthalocyaninato)iron derivatives RnPcFe [n= 4: R = CH2OEt (6e), CO2Et (6h), CO2‐n‐C6H13(6l), O(2‐Et‐n‐C6H13) (6j), OCH2C(CH3)3(6k), OCH2C(CH3)2CH2Ph (6l);n= 8: R = CH2CH(CO2Me)CH(CO2Me)CH2(6f), CH2CH(CO2Et)‐CH(CO2Et)CH2(6g), O‐n‐C8H17(6m), O(2‐Et‐n‐C6H13) (6n)] by starting from the corresponding substituted phthalonitriles led to substituted (μ‐oxo)bis[(phthalocyaninato)iron(III)]compounds [RnPcFe]2O. Thetert‐butyl‐ and ethyl‐substituted systems [tBu4PcFe]2O (6c) and [Et4PcFe]2O (6d) were reinve‐stigated. UV/Vis, FD mass, Mössbauer, NMR as well as ESR spectroscopy was used to characterize the complexes [RnPcFe]2O to furnish evidence for the presence of Fe‐O‐Fe moieties in [RnPcFe]2O. The UV/Vis data reported for [RnPcFe]2O as well as their spectral behavior in pyridine correspond to unsubstituted [PcFe]2O. Mössbauer spectra of [RnPcFe]2O show that the complexes were obtained as a mixture of two isomeric μ‐oxo compoundsA(δFe= 0.22 mm s‐1, ΔEQ= 1.33–1.39 mm s‐1) andB(ΔFe= 0.33–0.36 mm s‐1, ΔEQ= 0.39–0.53 mm s‐1), whose Mössbauer parameters are comparable to [PcFe]2O μ‐oxo(2) and μ‐oxo(1), respectively. Mössbauer spectral data of [RnPcFe]2O indicate high‐spin (S= 5/2) FeIIIcenters. NMR‐spectra of [RnPcFe]2O (n= 4: R =tBu, Et, O(2‐Et‐n‐C6H13), OCH2C(CH3)2CH2Ph;n= 8: R

ISSN:0009-2940    

DOI:10.1002/cber.19951280611

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY