Bonds In Organic Compounds Research Articles

A Critical Review of H-Atom Transfer in the Liquid Phase: Chlorine Atom, Alkyl, Trichloromethyl, Alkoxy, and Alkylperoxy Radicals

This review covers hydrogen-atom transfer from carbon-hydrogen bonds in organic compounds to chlorine atom, methyl, ethyl, trichloromethyl, t-butoxy and alkylperoxy radicals in the liquid phase. Rate constant data are presented in 38 tables. Literature is covered through most of 1972. The review is divided into six sections; an introduction plus five sections each dealing with specific radicals. Hydrogen-atom transfer to chlorine atom are presented as relative rate constants. For hydrogen-atom transfer to methyl, ethyl, trichloromethyl, and t-butoxy radicals, both relative and absolute rate constants are tabulated. For alkylperoxy radicals only absolute rate constants are listed. Each absolute rate constant has a tabulated set of rate parameters where A has been assigned and E derived from the Arrhenius equation.

The importance of orientation factors in enzymatic reactions.

It has long been well known that the bonds in organic compounds have a directional preference and this directional preference has an influence in reactivity (Pauling, 1931; Mulliken, 1932; Roberts, 1961; Ballhausen, 1964; Woodward and Hofmann, 1969). The magnitude of this orientation dependence, however, has not been evaluated precisely and it may be of great relevance to the theories of enzyme action. If this orientation factor is large, it could be capable of explaining a large part of the existing discrepancy between the velocity of enzymatic reactions and their non-enzymatic analogs. If, on the other hand, it is relatively small, it can make only a small contribution to the catalytic power of enzymes. Recently it was suggested that this number is large, as much as 104 per reacting pair (Storm and Koshland, 1970). Some further evidence and evaluation of this hypothesis is presented here.

Book Review: Electronic Carges of Bonds in Organic Compounds. By G. V. Bykov, translated from the Russian by J. T. Greaves, edited by R. W. Clarke

Angewandte Chemie International Edition in EnglishVolume 4, Issue 2 p. 178-178 Book Review Book Review: Electronic Carges of Bonds in Organic Compounds. By G. V. Bykov, translated from the Russian by J. T. Greaves, edited by R. W. Clarke M. Klessinger, M. KlessingerSearch for more papers by this author M. Klessinger, M. KlessingerSearch for more papers by this author First published: February 1965 https://doi.org/10.1002/anie.196501782AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume4, Issue2February 1965Pages 178-178 RelatedInformation

Electronic Charges of Bonds in Organic Compounds.

Electronic Charges of Bonds in Organic Compounds.

Distribution of?-electron density and interatomic distances Communication 4. Semiempirical equations for calculation purposes

1. Calculations were made of the constants occurring in semiempirical equations expressing the relation of interatomic distances to theπ -electron charges of bonds in organic compounds. 2. It was shown that in the case of C-C bonds changes inσ -electron charge have relatively little effect on interatomic distances. 3. It was noted that a nitrogen atom can act as a donor of threeπ -electrons.

Distribution of?-electron density and interatomic distances communication 5.?-electron charges of bonds in organic compounds

1. The lengths of C-H bonds in allene and ethylene and of C-C bonds in ethylene were calculated. 2. The π -electron charges of C-C bonds in anthracene, triphenylene, and ovalene were calculated. A comparison was made with Scherr's calculations. 3. It was shown that, when a nitrogen atom forms a bond with an atom-donor ofπ -electrons, the free pair of electrons almost always passes, wholly or partially, into the bond and increases itsπ -electron charge. 4. A table is given of π -electron charges in organic compounds. 5. A discussion is given of various hypotheses which have been advanced for the explanation of the regularities observed in interatomic distances.

The Binding Energy of Some Organic Compounds

MECKE (NATURE, April 5, p. 526) has recently revised several of his older estimates of the energy of dissociation of C-H and C-C bonds in organic compounds, obtaining values considerably higher than before. In these new calculations it is assumed that (a) the energy of removal of all of the hydrogen atoms in, say, methane, is the same, and (b) the carbon atom will be left in the 5S state with an excess energy amounting to about 110 kcal. It is then possible to calculate binding energies by the same methods which had been used before when instead of (b) the assumption was made that a normal carbon atom would be formed; clearly, the new energies will be higher than the old by 110/4 or 27.5 kcal. for C-H bonds, and 110/2 or 55 kcal. for C-C bonds. The dissociation energy for C-H in saturated hydrocarbons is thus increased from 90 kcal. to 117 kcal., and that of C-C from 65 kcal. to 120 kcal.