摘要:

AbstractThe effect of hydrogen fluoride on the polymerization of isobutene in heptane catalyzed with various FRIEDEL‐CRAFTShalides (TiCl4, TiBr4, TiJ4, VCl4, WCl6, PCl5, BCl3, SnCl4, SiCl4, GeCl4, and AsCl3) was investigated. It was found that hydrogen fluoride and the first eight halides form catalytic systems which are effective initiators of the polymerization of isobutene. From the experimental results it follows, that the catalytically active compounds are products arising from an exchange of the halogen atom between the individual FRIEDEL‐CRAFTS halides and hydrogen fluor

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740101

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractAs a functional vinyl monomer containing the 10‐isoalloxazinyl (2,4‐dioxo‐3H,10H‐benzo[h]pteridin‐10‐yl) residue, 10‐(2′‐methacryloyloxyethyl)‐3H,10H‐benzo[h]pteridine‐2,4‐dione (2) was prepared by reacting 10‐(2′‐hydroxyethyl)‐3H,10H‐benzo[h]pteridine‐2,4‐dione (1) with methacryloyl chloride in hexamethyl phosphoric acid triamide solution. Polymerization and copolymerization of the monomer were carried out by 2,2′‐azoisobutyronitrile. Alternatively, vinyl‐type polymers containing the isoalloxazine system (3) were also prepared by a polymer‐analogous reaction. Dehydrogenation reaction of methylmandelate was studied

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740102

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe polymerization of optically active phenyl‐α‐olefins, such as (R)‐4‐phenyl‐1‐hexene (1) and (S)‐5‐phenyl‐1‐heptene (2), has been performed by TiCl3/(“ARA”) or VCl4/Al[CH2CH(CH3)2]3catalyst.2gives polymers which are amorphous at room temperature; no evidence of stereoregularity is obtained by IR investigation, whereas1H‐NMR spectra seem to give some indication of steric order. By contrast, the polymers from1, which are largely insoluble in boiling solvents, are crystalline at X‐ray examination according to an isotactic structure. The copolymerization of1with 4‐methyl‐1‐pentene (3) gives statistical copolymers which appear to be coisotactic. This is confirmed by crystallinity at X‐ray exami

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740103

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe chiroptical properties of stereoregular polymers of optically active 4‐phenyl‐1‐hexene (1) and 5‐phenyl‐1‐heptene (2) as well as of the copolymers of1with 4‐methyl‐1‐pentene (3) were investigated. The comparison of the rotatory power and of the CD spectra in the spectral region of the π→π*electronic transitions of the aromatic chromophore of these polymers with the corresponding properties of optically active phenylalkanes allows the conclusion that the macromolecules of the homopolymer of1as well as of its copolymer with3contain chain blocks in helical conformation with a predominant direction of the screw. No evidence of this type was obtained for the polymers from2. Conformational analysis based on molecular models shows that in the case of1havingRabsolute configuration, the favoured direction of the screw is the right handed one as found for poly[(R)‐4‐methyl‐1‐hexene]. The relationships between the conformation of the macromolecules and CD of the phenyl chromophore between 275 and 185 nm are consistent with previous results concerning copolymers of styrene wi

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740104

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractEs wurden höhermolekulare α‐Brom‐ bzw. α‐Methyl‐ω‐hydroxy[(2‐hydroxy‐5‐methyl‐1,3‐phenylen)methylene] nach LEDERER und MANASSE dargestellt; die höchste erreichte rel. mol. Masse betrug rund 700. Mit steigender rel. mol. Masse wuchsen Zahl und Anteil der Nebenprodukte, so daß die Reinigung bis zur dünnschichtchromatographischen Reinheit immer verlustreicher wurde und die Ausbeuten auf 10–15% abfielen. Einige der Nebenprodukte wurden isoliert; ihre Konstitution wurde aufgeklärt und durch IR‐ und UV‐Messungen bestätigt. Tetrasubstitutionsbanden, Methylengruppen‐ und Hydroxylgruppenbanden der IR‐Spektren wurden eingehend untersucht. Die HUNTERsche Beziehung wurde bestätigt und

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740105

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe behavior of hydridonickel coordination compounds as catalysts for the oligomerization and polymerization of butadiene in various solvents was studied. In the presence of alcohol bis(tricyclohexylphosphine)chlorohydridonickel (4, X = Cl) (HNiCl[P(C6H11)3]2) catalyzes the linear dimerization. With hydridotetrakis(phosphite)nickel(1+) (2) ([HNi{P(OR)3}4]+), which is prepared from tetrakis(phosphite)nickel (1) (Ni[P(OR)3]4) and trifluoroacetic acid, dimerization occurs insec‐alcohol but there is no reaction intert‐alcohol. The main product is 2‐methylenevinylcyclopentane (8). The other products are 4‐vinylcyclohexene (10), 1,5‐cyclooctadiene (5), 1,3,7‐octatriene (7) and 1,3,6‐octatriene (9). The hydridonickel coordination compound, prepared with inorganic acids, does not afford the dimers but the 1,4

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740106

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe alternating copolymerization of acrylonitrile and butadiene in the presence of organo‐aluminum compounds of the type RAlCl2could be shown to be initiated by free radicals formed by cleavage of the AlR bond. The R• and radicals were detected under polymerization conditions by ESR spectroscopy, and the presence of the R groups in the copolymer and co‐oligomers could be confirmed by NMR and IR spectroscopy, and by elemental analyses. The results were discussed in terms of an initiation mechanism previously postulated by the

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740107

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractDie Umsetzung zwischen Butadien (M) undsec‐Butyllithium (BuLi) in einem Isooctangemisch wurde bei hohem BuLi/M‐Verhältnis im Temperaturbereich von −20°C bis +25°C untersucht; die Reaktionskinetik wurde mit Hilfe von IR‐Spektren untersucht. Für die Aktivierungsenergie der Startreaktion ergab sich ein Wert von 50 ± 17 kJ/mol (12 ± 4 kcal/mol), die Geschwindigkeitskonstante der Initiierung wurde bei 10°C zu 1,5 · 10−3dm3mol−1s−1bestimmt.Die Reaktionsordnung in bezug auf BuLi liegt zwischen 0,8 und 0,9. Dafür scheinen die Mischassoziate vom Typ (BuLi)n· (BuMLi)mverantwortlich zu sein. Ihre Bildung wurde durch die IR‐Spektren einer künstlichen Mischung vonsec‐BuLi mit Olig

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740108

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractPhotopolymerization of acrylamide (AM) sensitized by NaAuCl4·2H2O in aqueous system was investigated under irradiation at 365 nm. The rate of polymerization (Rp) was strongly influenced by the change of the pH and the chloride concentration. The results were interpreted assuming different initiating efficiencies for various hydrolyzed species of Au(III). From the dependence ofRpon the wavelength, the effective photoabsorption was confirmed to be due to the excitation of the CTTM (charge transfer to metal) band of Au(III). The monomer participated in the photodecomposition of Au(III), eventually leading to Au(0). Under thermal conditions the polymerization was greatly accelerated by the addition of reducing agents, indicating that active species were produced during the reduction of Au(III) to lower valency states. The kinetic expression of photopolymerization was the expected one for a radical polymerization

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740109

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0025-116X    

DOI:10.1002/macp.1973.021740110

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY