Ab initio and density functional studies of cooperative hydrogen bonding in calix4-and calix6arenesReportar como inadecuado




Ab initio and density functional studies of cooperative hydrogen bonding in calix4-and calix6arenes - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Journal of Structural Chemistry

, Volume 47, Issue 6, pp 1003–1015

Received: 13 July 2005Revised: 18 April 2006

Abstract

The cone conformation of C4 symmetry is shown by the Hartree-Fock method 3-21G basis to be the predominant conformer of calix4arene; the compressed cone of C2 symmetry is the major conformer of calix6arene. Using quantum chemical methods we calculated hydrogen bond cleavage energies for calix4-ab initio and density functional methods and calix6arene ab initio, and also for the complex of calix4arene with carbon disulfide. These energies along with structural data point to the cooperative effect of hydrogen bonds. The results of these studies provided an explanation to the greater conformational lability of calix6arene compared with calix4arene molecules. It is also predicted that the nucleophilic substitution reaction involving calix6arene in the presence of weak bases and in aprotic solvents, as well as in the gas phase, will occur via diastereomeric transition states.

Keywordscalix4arene calix6arene ab initio and density functional methods hydrogen bond cooperative effect compressed cone conformer Original Russian Text Copyright © 2006 by A. N. Novikov, V. A. Bacherikov, Yu. E. Shapiro, and A. I. Gren

Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 6, pp. 1015–1027, November–December, 2006.

Download to read the full article text



Autor: A. N. Novikov - V. A. Bacherikov - Yu. E. Shapiro - A. I. Gren

Fuente: https://link.springer.com/



DESCARGAR PDF




Documentos relacionados