摘要:

AbstractOrganic photochemical reactions can be understood as transformations of the electronically excited states of the reactant molecules. By considering Lewis structure or molecular orbital representations of these excited states it is possible to outline the several possible reactions available in the case of a given reactant. A number of different types of photochemical transformations are now reasonably well understood. In these cases one finds the same common controlling feature, namely the tendency for an excited state species to follow mechanistic pathways of minimum energy and the requirement for continuous electron redistribution in following these pathways. These preferred transformations can often be selected by inspection of relative bond orders for different types of bonding, by comparison of the potential energy surfaces available to the excited state molecules, and by use of correlation diagrams. The reactions derive from both singlet and triplet states, and one of the more reliable methods now available for identifying excited states reacting is termed the “fingerprint method”. Examples of the author's mechanistic approach are given both for ketone and for hydrocarbon photochemis

ISSN:0570-0833    

DOI:10.1002/anie.196900011

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractMutations and recombinations are hereditary alterations of DNA, which is found mainly in the chromosomes of cells. They can occur spontaneously and they can be induced by high energy radiation or by chemicals. This article considers the developments following the discovery of the DNA structure that have led to a molecular explanation of point mutations, of large chromosome alterations, and of recombination. In conclusion, consequences for human society are drawn from the knowledge gained.

ISSN:0570-0833    

DOI:10.1002/anie.196900121

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractThe readily obtainable isocyanide dichlorides can be used as starting materials for the preparation of many types of substances. Exchange reactions yield numerous derivatives of formic and carbonic acids, while heterocyclic products have been obtained by reaction with bifunctional partners. The present article deals not only with reactions that are known from the literature but also with the author's own work, some of which has not been published before.

ISSN:0570-0833    

DOI:10.1002/anie.196900201

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractPlanar complexes, and particularly those of platinum, can form structures containing linear chains of heavy metal atoms with metal‐metal distances as short as 3.1 Å. The bonding in these chains can be strengthened by partial oxidation, and the bond lengths can be reduced to 2.8 Å in this way. Model structures for the novel nonstoichiometric products, such as K2[Pt(CN)4]Cl0·32· 2.6 H2O, are considered. The bonding is also discussed on the basis of a one‐dimensional ban

ISSN:0570-0833    

DOI:10.1002/anie.196900351

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractThe realization that many elementary biological processes occur at membrane‐like structures has led to renewed interest in the theory of molecular transport through membranes. Coupling phenomena in membranes, some of which are very complex, can now be rationally described with the aid of the thermodynamics of irreversible processes. The investigation of theoretical membrane models has proved a valuable complement to the thermodynamic metho

ISSN:0570-0833    

DOI:10.1002/anie.196900421

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractMolecules formed from atoms of Groups V–VIII of the periodic table in their higher valences are studied and a general theory for their electronic and geometric structure is presented. These molecules, which we call hypervalent molecules, are unique in that a donor atom can possess two identical monovalent ligands which are bonded by different types of chemical bonds. The present study provides a simple theoretical description of such molecules using doubly‐occupied lone‐pair orbitals to form hypervalent bonds, and these bonds are divided into two classes as to whether they involve p electrons alone or utilize s electrons as well. While the theoretical classification is of some interest in itself, there are even more interesting problems concerning the physico‐chemical properties of these molecules and the syntheses of new molecules and polymers. We thus present a brief description of the energetics, possibilities for intermolecular inversion and site‐exchange, and synthetic paths for the preparation of hypervalent molecules, as well as indicate a number of new molecules which can probably be synthesized using these ideas.For corrigendum see DOI:10.1002/anie

ISSN:0570-0833    

DOI:10.1002/anie.196900541

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196900681

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196900692

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196900701

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196900711

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY