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Molecular charge distribution and chemical binding in five-membered heterocycles. I

✍ Scribed by Rifaat Hilal

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
807 KB
Volume
1
Category
Article
ISSN
0192-8651

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✦ Synopsis

Abstract

Electron density maps for the heterocycles thiophene, furan, and pyrrole are determined from ab initio 4‐31G wavefunctions. The charge distributions in these molecules are analyzed in terms of the total molecular density and difference density maps and their profiles. The atomiclike core, especially the L core of sulfur, is found to play an important role, via its polarization and interaction, in determining the extent and direction of valence density transfer from the carbon to the heteroatom. The changes in the charge distributions that occur in the immediate vicinity of the heteroatoms and the relation of density quantities to binding and antibinding characteristics are discussed. The quantum topological features of the molecular charge distributions of the three heterocycles are analyzed and discussed and the different bonding situations, e.g., ring strain, ionic and covalent binding, etc., are compared in a model‐independent way.

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