CCSD(T)-F12a study of reactions of interstellar anions C2nH-(n = 2-4) with HCCH

Explicitly correlated coupled cluster theory at the CCSD(T)-F12a level (Adler, T. B.; Knizia, G.; Werner, H.-J. J. Chem. Phys. 2007, 127, 221106) was employed to study the energetics of reactions of interstellar anions C(2n)H(-) with HCCH, which may formally be regarded as proton-transfer reactions....

Full description

Saved in:
Bibliographic Details
Published in:The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2010-04, Vol.114 (14), p.4875-4880
Main Authors: Botschwina, Peter, Oswald, Rainer
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Explicitly correlated coupled cluster theory at the CCSD(T)-F12a level (Adler, T. B.; Knizia, G.; Werner, H.-J. J. Chem. Phys. 2007, 127, 221106) was employed to study the energetics of reactions of interstellar anions C(2n)H(-) with HCCH, which may formally be regarded as proton-transfer reactions. The gas-phase acidities at 0 K for the polyynes HC(2n)H with n = 2-4 are predicted to be 1516.5, 1483.2, and 1462.6 kJ mol(-1). The energy profiles of the collinear reactions are characterized by absolute minima corresponding to the hydrogen-bonded species HC(2n)(-)...HCCH, saddle points at which the proton is shared between the two anion moieties, and a second minimum in the exit channel of the reaction, which becomes less pronounced with increasing n.
ISSN:1520-5215
DOI:10.1021/jp910415a