TITLE

C3v versus C2v Cd(1S,3P,1P)–CH4 van der Waals complexes: A variational and perturbational multireference configuration interaction study

AUTHOR(S)
Ramírez-Solís, Alejandro; Castillo A., Sidonio
PUB. DATE
May 1993
SOURCE
Journal of Chemical Physics;5/15/1993, Vol. 98 Issue 10, p8065
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The Cd(1S,3,1P)–CH4 interaction is studied for the C3v vertex-on Cd(1S,3,1P)–HCH3 and face-on Cd(1S,3,1P)–H3CH approaches as well as the C2v Cd(1S,3,1P)–H2CH2 edge-on approach of the metal atom to methane using extensive ab initio multireference configuration interaction plus second order multireference Mo\ller–Plesset calculations. The ground state Cd(1S)–CH4 is totally repulsive for the C3v vertex-on and C2v edge-on approaches. Only a stable face-on Cd(1S)–H3CH complex was found. Although vertex-on and edge-on minima were found for the Cd(3P)–CH4 excited complexes, they are less attractive than the corresponding Cd(3P)–H3CH face-on exciplexes. The optimal orientation of the face-on occupied 5p orbital of Cd(5s5p) is that which minimizes the overlap with C–H bonds leading to a ‘‘3Πy’’ exciplex. For the Cd(1P)–CH4 interaction, two face-on and two edge-on very stable complexes (all with De≥1300 cm-1) were found. The Cd(1S)–H3CH (1A1) complex was found to have a 185 cm-1 well at 8.03 a.u. Both excited P states present shorter equilibrium distances—the Cd(3P)–H3CH (3E) exciplex has a 799 cm-1 well at 6.08 a.u., while the Cd(1P)–H3CH exciplex (1E) has a 1337 cm-1 well at 5.57 a.u. These results are in good agreement with the recent experimental values X 1O+(1S)—(De=121 cm-1, Re=7.9 a.u.); A 3O+(3P)—(De=677 cm-1, Re=5.80 a.u.); and 1P—(De[bar_over_tilde:_approx._equal_to]1300 cm-1, Re=5.59 a.u.) obtained by Wallace and Breckenridge [J. Chem. Phys. 97, 2318 (1992)]. The present work confirms the C3v facial nature of the observed (1S) ground and (3P) excited complexes. The present results are inconclusive as to the facial or edge-on nature of the Cd(1P)–CH4 exciplex, but they preclude the C3v vertex-on possibility.
ACCESSION #
7643752

 

Related Articles

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics