AB INITIO STRUCTURES FOR 90$^{irc}$-TWISTED {\em s-trans}-1,3-BUTADIENE AND FOR CYCLOOCTATETRENE; THE NAKED sp$^{2}$-sp$^{2}$ BOND AND OTHER DISCLOSURES ABOUT EQUILBRIUM STRUCTURES OF BUTADIENE

Research Projects

Organizational Units

Journal Issue

Abstract

The bond length of a carbon-carbon sp$^{2}$-sp$^{2}$ $\sigma $-bond without the perturbing effects of $\pi $-electron interactions has been estimated by high-level ab initio calculations [CCSD(T)/cc-pVNQ with CBS extrapolation] on two prototypical systems: a 90$^{irc}$-twisted form of butadiene and the tub conformer of cyclooctatetraene. The butadiene system yields a value of 1.4818 \AA, considerably longer than previous estimates. The corresponding bond length in cyclooctatetraene is slightly shorter due to some $\pi $-electron delocalization. Ab initio results for related equilibrium structures of other rotamers/transition states of butadiene along the internal rotation coordinate (C-C bond) will be reported and compared with an experimental potential function.}

Description

R. Engeln, D. Consalvo, J. Reuss, Chem. Phys. 160, 427 (1992).
Author Institution: Department of Chemistry, Washington State University, Pullman, WA 99164-4630; Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH 44074

Keywords

Citation