The willgerodt-kindler reactions. 7. The mechanisms

The mechanisms involved in various stages of the Kindler Reaction are discussed, with particular attention especially to its most unusual feature: the movement of a carbonyl group from methylene carbon to methylene carbon in an unbranched alkyl chain, or around a cycloalkyl ring. The first step is the reversible formation of an enamine, which is attacked by a catalyst generated from sulfur and the amine solvent to form a highly reactive intermediate with a sulfur-containing heterocyclic ring. The natures of the catalytically active species and the reactive intermediates are proposed. Other steps involved in the Kindler Reaction are also discussed, as is the relationship of the Willgerodt Reaction to the Kindler Reaction.     

The freeon theory of magnetism. I. The Heisenberg interaction

The freeon theory of magnetism is a viable alternative to the well-known Heisenberg theory. In particular, the freeon-exchange theory provides a deeper insight into the nature of the magnetic interaction than does the spin-exchange theory. In addition, it avoids the superfluous M_S quantum number in zero-field splitting, the overcounting of spin states, the spin frustration, and the spin paradigm. The freeon-exchange theory employs the algebra of the symmetric group and/or the unitary group in place of the spin algebra. The basis vectors of freeon theory are the Gel'fand states which are uniquely labeled by Gel'fand diagrams; the latter provide both the electron configuration and the spin quantum number. Both the spin and the freeon formulations support the Landé interval rule. In this article, we apply freeon theory to transition-metal dimers, trimers, and tetramers; these are examples of molecular magnets which have applications to microcircuitry. The freeon theory follows the permutation-group principle laid down by Herman Weyl over one-half a century ago. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 65 : 287–297, 1997     

The glycosides ofApocynum androsaemifolium L. II. The structure of apobioside

The roots of the plantApocynum androsaemifolium L. contain a new steroid diglycoside, apobioside, which has the structure cannogenin-(3)--D-cymaropyranoside-(4)--D-glucopyranoside.Khimiya prirodnykh soedinenii, Vol. 1, No. 1, pp. 15–22, 1965     

The nature of topological parameters. II. The composition of topological parameters

The composition of thirty topological parameters of various types including the , and parameters and the Wiener indices was determined. Those derived from alkyl and substituted alkyl groups are a function of branching and steric effects; those derived from haloalkanes and haloalkenes are a function of some combination of polarizability, dipole moment, the number of halogen atoms of each type, and the ration of the number of branches to the number of atoms in the longest chain. It follows that topological parameters are actually counts of the number of atoms of each type, bonds of each type, valence, nonbonding and core electrons, branches at each position, OH and NH bonds, and nonbonding electron pairs on O and/or N atoms. These counts can be related to polarizability, dipole moment, hydrogen bonding, and steric effects, which are the true determinants of properties and biological activities. Topological parameters themselves do not have a cause and effect relationship with the quantities they are used to model. They function because:1. They are counts of quantities that are related to the fundamental quantities that determine properties.2. They are composite parameters which for the purpose of obtaining a predictive empirical relationship are able to represent a data set as well as pure parameters.     

交流示波极谱图重现性的研究

本文用集成运放为主要元件改进了交流示波极谱的实验线路,并用该线路在严格控制实验条件的情况下,对交流示波极谱图的重现性进行了系统的研究。实验表明,交流示波极谱图的重现性良好,可将其用于有机化合物及有机药物的定性鉴定。     

The properties of ion-water clusters. I. The protonated 21-water cluster

The ab initio atom-centered density-matrix propagation approach and the multistate empirical valence bond method have been employed to study the structure, dynamics, and rovibrational spectrum of a hydrated proton in the "magic" 21 water cluster. In addition to the conclusion that the hydrated proton tends to reside on the surface of the cluster, with the lone pair on the protonated oxygen pointing "outwards," it is also found that dynamical effects play an important role in determining the vibrational properties of such clusters. This result is used to analyze and complement recent experimental and theoretical studies.     

The problem of fullerenes. The chemical aspect

The preparation, structure, and reactivity of the family of polyhedral carbon clusters, novel allotropes of carbon, are reviewed.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 10–19, January, 1993.