摘要:

Chemistry of Excited States. XII. MO Calculation of the Electronic Spectrum of Pyridin‐N‐Oxid – A Critical AnalysisMO calculations (ab initio, HAM/3, INDO‐, CNDO‐ and PPP‐Typ including CI) are reported with regard to the interpretation of the u.v. spectrum of the title compound.The different semiempirical methods show similar results concerning the energies of the ππ* transitions.For the absorption at 5.72 eV, differences are found between the ab initio and all semiempirical calculations concerning the interpretation of this transition (A1or B2).None of the methods yields results exactly enough to predict the dipole forbidden (A2) and allowed (B1) nπ* trans

ISSN:0021-8383    

DOI:10.1002/prac.19823240112

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

Chemical Synthesis of the Dodeecanuceleotide. dCACAAGCTTGTGFor studies of some sequence dependent structural factors the self‐complementary dodecanucleotide dCACAAGCTTGTG was required. Its chemical synthesis is reported according to the diester approach startin

ISSN:0021-8383    

DOI:10.1002/prac.19823240113

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

Influence of Substituents on the T1Energy and the S1‐T1Energy Gap in ω‐Phosphorus Substituted trans‐StyrenesThe fluorescence and the phosphorescence of 4‐substituted ω‐diphenylphosphinyl trans‐styrenes1and analogous diphenylthiophosphinyl trans‐styrenes2at 77 K indicate together with some oxygen‐induced singlet‐triplet absorption spectra a bathochromic shift of the lowest singlet (S1) and the lowest triplet level (T1) relatively to the S1and T1level of the unsubstituted compounds1aand2a, respectively. Donor substituents X in 4‐position give rise to a shift of S1, which is in the most cases much greater than that of T1, so that the S1–T1energy gap decreases. P(Y)R1R2groups (Y = O, S) in ω‐position of1and2effect a small bathochromic shift of the T1energy level only (130–900 cm−1relatively to unsubstituted styrene). S1is shifted 860–208

ISSN:0021-8383    

DOI:10.1002/prac.19823240114

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

Metalloporphyrin Complexes. VI. Synthesis of Polymethacrylates with Covalently Bound Iron (III)‐protoporphyrin IXConvenient synthesis of polymeric iron (III)‐protoporphyrin IX (hemin) compounds is described. The covalent linkage via the carboxylic groups of hemin is possible by the reaction of the activated ester of hemin with polymethacrylates containing aliphatic amino groups. Polymethacrylates with aromatic amino groups are suitable to immobilize the hemin via its methine bridges. The hemin‐containing polymers are characterized by visible spectra and e.p.r.‐spect

ISSN:0021-8383    

DOI:10.1002/prac.19823240115

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

Studies on the Autoxidation of Branched‐chain Olefins. I. Autoxidation of 2‐Methylalk‐1‐enes and 2‐Methylalk‐2‐enesThe products of the autoxidation of 2‐methylpent‐1‐ene, 2‐methylpent‐2‐ene, 2‐methylhex‐1‐ene, 2‐methylhex‐2‐ene, 2,4,4‐trimethylpent‐1‐ene, and 2,4,4‐trimethylpent‐2‐ene were analyzed by gas chromatography. The identification of the products corresponding to the individual peaks was possible by comparison with authentic substances or by preparative gaschromatographic separation and n.m.r.‐spectroscopy of the isolated samples. In this way not only the epoxides and the products of the oxidative cleavage of the CC‐double bond but also the allylic alcohols formed by LiAlH4‐reduction of the oxidation mixtures could be identified and analyzed. From the results the compos

ISSN:0021-8383    

DOI:10.1002/prac.19823240116

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19823240117

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19823240118

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19823240119

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19823240120

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19823240121

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY