Bibliography 1975–76 Organic and Organometallic Crystal Structures


Book Description

This volume is the eighth classified bibliography of organic and organometallic crystal structures prepared by the Crystallographic Data Centre, University Chemical Laboratory, Cambridge, and published jointly with the International Union of Crystallography. The first seven volumes covered the years 1935-1975. The present volume provides references principally to compounds whose struc tures were reported in the literature during 1975-1976. A few structures published prior to 1975 and omitted from the previous volumes are also included. This volume incorporates some major changes in methods of preparation, indexing, and literature coverage. These changes are designed to give a later cut-off date for the literature coverage, and to make the main classified listing more accessible to the reader through improved indexing. The major technical change was the use of the FR80 microfilm recorder at the Science Research Council Rutherford Laboratory, instead of the Linotron 505 filmsetter, to prepare the master copy of the book. The change necessitated the development of a new set of prQgrams, a project carried out in collaboration with the Atlas Computing Division of the Rutherford Laboratory. The reader may also notice the use of a new type font, developed by Dr A. V. Hershey and made available by Mrs Carla Messina, Dr N. M. Wolcott and Mr J. Hilsenrath of the USA National Bureau of Standards.




Molecular Structures and Dimensions


Book Description

This volume is the fourteenth classified bibliography of organic, organometallic and metal complex crystal structures prepared by the Cambridge Crystallo graphic Data Centre and published jointly with the International Union of Crystallography. The previous thirteen volumes covered the years 1935-81; the majority of references in the present volume pertain to structure analyses reported in the literature during 1981 and 1982. A few structures reported prior to 1981 and omitted in earlier volumes are also included. Volume 14 contains 4094 references to 4001 distinct chemical compounds with 2162 cross-references. Some 90% of these references were obtained by direct in-house scanning of 51 major journals; the remaining material was located by searching Chemical Abstracts and Bulletin Signa/etique. The table below summarizes the cut-off dates for the 25 direct-scan journals yielding most entries in Volume 14. The fully classified Chemical Diagram Index, first presented in Volume 13, is continued here. Volume 14 contains 3912 chemical structural diagrams, repre senting 98% of the compounds. The reasons for the omission of some diagrams are noted in the Introduction. This new index provides a rapid visual overview of compounds studied in 1981-82 and will, we hope, add greatly to the usefulness of the annual Bibliographies. The textual indexes in Volume 14 continue the system established in Volumes 9-13 and in the special volume Guide to the Literature 1935-76. The latter volume presents a set of cumulative indexes to the contents of Bibliographic Volumes 1-8.













Organometallic Compounds


Book Description

A very large number of organo derivatives is formed by the Group IV ele ments silicon, germanium, tin, and lead. In comparing the general properties of these elements, Table 1. 1 shows that the first ionization energies decrease (though not in a regular way) with increase in size and atomic number, con sistent with the general increase in metallic character of the elements. Electro negativity values (which have been the subject of considerable controversy) show no clear trend. Although purely inorganic compounds of tin(n) and leaden) are well known, almost all organo Group IV derivatives show an oxidation state of IV. Bonds to carbon become weaker on passing from silicon to lead, as do the element-element bonds themselves. With any particular element M (M = Si, Ge, Sn, or Pb), there is a small decrease in bond energy in the order: M-Ph > M - Me > M - Et. Although accurate data for organo derivatives are lacking, strengths of bonds to other elements probably decrease in the order: M-F> M-O > M-CI > M-H ~ M-N ~ M-S ~ M-Br > M-I, while for a particular element X, the order is: Si-X > Ge-X > Sn-X > Pb-X. It is therefore understandable that reactions leading to Si-F, Si-O, or Si-CI bonds are especially favoured in a thermodynamic sense.




Subject Catalog


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ERDA Energy Research Abstracts


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