摘要:

AbstractCationic polynucleotide model compounds such as poly[N‐(adenosin‐5′‐yl)iminoethylene hydrochloride‐co‐N‐(5‐ribosyl)iminoethylene hydrochloride‐co‐iminoethylene] (1a) and poly‐[N‐(uridin‐5′‐yl)iminoethylene hydrobromide‐co‐N‐(5‐ribosyl)iminoethylene hydrobromide‐co‐iminoethylene] (1b) were synthesized by alkylation of linear poly(iminoethylene) with 5′‐chloro‐5′‐deoxyadenosine and 5′‐bromo‐5′‐deoxyuridine, respectively. In aqueous solution the adenine moieties of1aare stacked one above the other, whereas the uracil moieties of1bare scarcely stacked. These model compounds interact with mononucleotides at relatively low concentration (0,5 mmol.dm−3). The magnitudes of UV hypochromicities are decreasing for the various systems in the order of purine/purine>purine/pyrimidine>pyrimidine/pyr

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811101

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractPoly[4‐(1,1,3,3‐tetramethylbutyl)phenyl methacrylate] (1a) was synthesized and its physicochemical properties were determined in the condensed phase and in dilute solution. The polymerization of 4‐(1,1,3,3‐tetramethylbutyl)phenyl methacrylate was carried out by radical mechanism in solution with 2,2′‐azoisobutyronitrile as initiator. Several samples were characterized by their intrinsic viscosity, by osmometric measurements, differential scanning calorimetry, and X‐ray diffraction. The viscometric behaviour of fractions of1awas studied in good solvents and theta solvents, and the conformational parameters were calculated. Polymer1apresents an unusual high rigidity in the chain. X‐Ray diffraction of this polymer indicates a one‐dimensional ordering of a

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811102

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractTo establish appropriate reaction conditions for the synthesis of new monomers having a secondary amino group, a lithium alkylamide catalyzed addition reaction of primary amines with styrene was examined as the model reaction. The selectivity ofN‐alkyl‐2‐phenethylamines (2) and the rate constant of the reaction were determined. On the basis of results of the model reaction, new styrene derivatives having a secondary amino group (5) were synthesized by lithium alkylamide catalyzed addition reactions of primary amines with 1,4‐divinyl

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811103

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractLithium alkylamide catalyzed addition reaction ofN‐alkylethylenediamines (1) with styrene was examined. It was found thatN‐alkyl‐N‐(2‐phenethyl)ethylenediamine (3) was formed selectively in preference toN‐alkyl‐N′‐(2‐phenethyl)ethylenediamine (4). The identification of products was carried out by13C NMR. On the basis of the results obtained, a new type of styrene derivative having a primary amino group (6) was synthesized by lithium alkylamide catalyzed addition reaction of1with

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811104

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractAllyl vinyl ether can be polymerized to highly isotactic polymer with SbCl5in toluene at ca. −10°C. The stereospecificity isnotsignificantly lower than that of polymer made at ca. −75°C; The reproducibility of the process is greatly improved at the higher temperature. BF3.O(C2H5)2proved to be an ineffective initiator, in contrast with literature data. NMR analysis, previously published for diads only from NMR data, was performed (1H and13C) for triads as well, and partly for hexads. No evidence for stereocontrol other than the relationship between active chain end HC⊕OAllyl and incoming monomer can be inferred1cf. Part 2 of this series10.. A simple mechanism, featuring association between incoming monomer and counterion, invoking only steric hindrance is proposed as an explanation of these f

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811105

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractCryotachensic copolymerization of chloral with various aliphatic and aromatic isocyanates, initiated by lithiumtert‐butoxide and triphenylphosphine at 0°C, was followed by1H NMR spectroscopy. Information on the mobility of comonomers and solvent molecules in the polymerization mixture was obtained by measuring the line width of the signals. Relative rates of incorporation of chloral and isocyanates into the copolymer were determined, indicating that the copolymer was not uniform in structure and that the content of isocyanate units increased significantly in the final stages of copolymerizati

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811106

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractPolymerizations of acrylonitrile, methacrylonitrile, methyl acrylate, and methyl methacrylate initiated by the system ethylaluminium dichloride (EtAlCl2)‐p‐chloranil (PClA) were studied. The effect of the catalyst system components on the initiation, propagation and termination steps is discussed in terms of a free radical reaction mechanism. The catalytic system EtAlCl2‐PClA behaved similarly in the copolymerization of MMA with styrene as in the free radical homopolymerization of MMA. Polymerizations of vinyl monomers, not forming relatively stable complexes with EtAlCl2(in contrast to acrylic and methacrylic monomers), such as vinyl chloride, styrene and isobutylene, were also studied in the presence of the EtAlCl2‐PClA

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811107

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractThe ternary copolymerization of carbon dioxide with 1,2‐epoxybutane and other epoxybutane isomers using the diethylzinc/water system as catalyst was carried out to investigate the relative reactivity between epoxides.cis‐2,3‐Epoxybutane was much more reactive thantrans‐2,3‐epoxybutane in the copolymerization with carbon dioxide. The copolymer obtained from the reaction of carbon dioxide andcis‐2,3‐epoxybutane upon hydrolysis gavethreo‐2,3‐butanediol, indicating the exclusive inversion of configuration in the ring‐opening of the epoxide. In the formation of cyclic carbonate as a byproduct of the copolymerization,cis‐2,3‐epoxybutane andtrans‐2,3‐epoxybutane exh

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811108

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractFormation and behaviour of radiation induced free radicals in statistical copolymers from vinyl hydrosulfide and styrene (1:1, 1:4, and 1:10) were investigated by means of ESR spectroscopy. The corresponding homopolymers were also included in these studies. After γ‐irradiation of the copolymers at 77 K and subsequent annealing to 293 K it was possible to detect thio radicals. Their relative yields were found to increase with increasing styrene content. Investigations regarding the thermal behaviour of the radiation induced radicals in the copolymers allowed the assumption of two mechanisms responsible for the formation of the thio radicals: First, the formation takes place via ion radicals located at the mercapto groups at 77K. In the copolymers the stability of the thio radicals is favoured by steric hindrance through the benzene rings thus reducing the formation of disulfide bridges as termination reaction. Secondly, the formation of the thio radicals is caused by a hydrogen transfer from the mercapto groups to the benzyl radicals and/or cyclohexadienyl radicals of styrene uni

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811109

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractNew Polysaccharide‐type polymers containing amino groups in their main chains were synthesized by chemical modification of poly(5,6‐dihydro‐2H‐pyran‐6,2‐diyloxymethylene) (2). Thus, the unsaturated polyacetal2, having a dihydropyran ring in the repeating unit, was obtained by ring‐opening polymerization of 6,8‐dioxabicyclo[3.2.1]oct‐3‐ene (1), and it was epoxidized withm‐chloroperoxybenzoic acid followed by the reaction of the epoxide with ammonia or dimethylamine in aqueous solutions to yield polysaccharides containing the corresponding β‐aminoalcohol groups (4aand4b). Visible spectroscopy revealed that4aand4binteracted with copper(II) ion in aqueous solutions. A qualitative biological test showed that both4aand4binhibited the growth of microorganisms. Sulfated derivatives of4aand4bwere prepared by reaction of4aand4bwith chlorosulfuric acid in formamide. Their anticoagulant activities were evaluated by the “Activated Partial Thromboplastin Time (APTT) method” and compared

ISSN:0025-116X    

DOI:10.1002/macp.1980.021811110

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY