WEAK ION-MOLECULE COMPLEXES OF F-(CF4)(N) AND CF3-(CF4)(N)

Citation
K. Hiraoka et al., WEAK ION-MOLECULE COMPLEXES OF F-(CF4)(N) AND CF3-(CF4)(N), Chemical physics letters, 245(1), 1995, pp. 14-18
Citations number
15
Categorie Soggetti
Physics, Atomic, Molecular & Chemical
Journal title
ISSN journal
00092614
Volume
245
Issue
1
Year of publication
1995
Pages
14 - 18
Database
ISI
SICI code
0009-2614(1995)245:1<14:WICOFA>2.0.ZU;2-9
Abstract
Gas-phase thermochemical stabilities and structures of cluster ions F- (CF4)(n) and CF3-(CF4)(n) have been studied with a high-pressure mass spectrometer and ab initio calculations. The F-...CF4 bonding energy i s found to be only 6.4 kcal/mol, Its geometry is of an ion-dipole comp lex along an S(N)2 reaction path. The high-symmetry (D-3h) CF5- specie s is computed to be a transition state of the S(N)2 path and not an en ergy minimum. The CF3-...CF4 bonding energy is only 3.6 kcal/mol with F2C-F-...CF4 coordination. The F...F exchange repulsion hinders the F. ..C attractions in these species. Theoretical bonding energies are in good agreement with measured ones.