摘要:

AbstractPhotoconduction in organic dyes is caused by the formation and migration of electronic charge carriers, and is not due to impurities or photochemical decomposition. The phenomena of dark and light‐induced conduction in dyes can therefore be interpreted in the same way as in inorganic semiconductor

ISSN:0570-0833    

DOI:10.1002/anie.196506191

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe reaction of liquid hydrogen fluoride with nitrous acid, dinitrogen trioxide, dinitrogen tetroxide, and nitrosyl compounds leads to unexpectedly high‐boiling liquids which contain nitrosyl fluoride in the form of remarkably stable, electrolytically dissociated hydrogen fluoride solvates. Nitrosyl fluoride solvated by pure hydrogen fluoride is a new reagent, valuable in fluorine chemistry since it reacts with many elements and compounds to form fluorine derivatives of preparative importanc

ISSN:0570-0833    

DOI:10.1002/anie.196506351

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractFluorosulfuric acid is known both in aqueous solution and as the anhydrous compound. The anhydrous acid exhibits electrical conductivity which indicates its autodissociation. Even strong acids such as H2SO4or HCIO4behave as proton acceptors, i.e. as bases, in fluorosulfuric acid. Volatile inorganic acid fluorides can be readily prepared using fluorosulfuric acid as fluorinating agent.

ISSN:0570-0833    

DOI:10.1002/anie.196506411

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe reaction of alkylidenephosphoranes with compounds containing halogens can be used to prepare ylides, which can be converted in to useful products, e.g. by hydrolysis, by thermal decomposition, or by other reactions. Examples of such products are ketones including cyclic, unsaturated, and branched‐chain ketones (including cyclic, unsaturated, and branched‐chain ketones), carboxlic esters (including those of unsaturated, branched‐ chain, polyenecarboxylic, acetylenecarboxylic, and allenecarboxylic acids), and alde

ISSN:0570-0833    

DOI:10.1002/anie.196506451

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractStarting from classical concepts, semi‐empirical approaches to an understanding of the chemical bond are critically discussed, particularly with respect to their limitations. Rules such as the additivity of the bond constants and the octet rule are reviewed in relation to new chemical compounds. It is shown that these rules are not sufficient to explain chemical bonding; this is also true of the simple concept of hybridization, the basis of which is discussed. Some generally valid statements regarding the chemical bond can be propounded on the bais of wave‐mechanical considerations. It is shown that the hybridization concept and a number of other rules are too primitive to provide generally valid information or a basis for predictions about the chemical bond, and even that they are partly based on false premises. A better foundation for an understanding of the chemical bond can only be laid with the aid of wave mechan

ISSN:0570-0833    

DOI:10.1002/anie.196506601

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractAn attempt is made to create a basis for the understanding of flavin‐ (Vitamin B2‐) dependent oxidations in terms of molecular structure. The main points of this survey can be summarized as follows: (a) The flavins must be differentiated according to their redox states (quinone state, radical state, hydroquinone state), since configuration, energy content of the tautomeric forms, metal affinity etc., alter drastically during reduction. – (b) The methyl group on C‐8 of the flavoquinone is reactive. – (c) The electron transfer properties of the flavin system frequently depend on the coupling of secondary redox systems to the apoprotein. This interaction thermodynamically stabilizes the half‐reduced state of the flavin. – (d) Numerous novel flavin types, among them stabilized free radicals, have become available through syntheses at the dihydro stage. – (e) Reaction of the flavin radical with O2is slow as long as no disproportionation occurs, i.e. the fast flavin autoxidation proceeds via the dihydro state. – (f) The flavin nucleus gains affinity for heavy metal ions only by the acceptance of one, and only one, electron. – (g) Redox activity and contact with the flavin coenzyme have been confirmed for Fe and Mo, which occur in flavoproteins. The properties of the metal coordination sphere are determined primarily by sulfur‐containing gro

ISSN:0570-0833    

DOI:10.1002/anie.196506711

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196506882

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196506892

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196506901

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196506912

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY