Bm. Ladanyi et R. Parson, STRUCTURE AND DYNAMICS OF MOLECULAR-IONS IN CLUSTERS - I-2(-) IN FLEXIBLE CO2, The Journal of chemical physics, 107(22), 1997, pp. 9326-9338
The structures and dynamics of I-2(-) molecular ions embedded in clust
ers of flexible solvent molecules are studied using molecular dynamics
simulation. The potential model extends the work of Papanikolas et al
. [J. Chem. Phys. 102, 2452 (1995)] by taking into account the low-fre
quency bending vibrations of the solvent molecules. Results are presen
ted for flexible CO2 and for a hypothetical solvent in which the bendi
ng force constant of CO2 has been decreased by a factor of 5. The stru
cture and the vibrational relaxation dynamics of I-2(-) in flexible CO
2 differ only slightly from what was seen in rigid CO2. In ''hyperflex
ible'' CO2, however, the solute becomes strongly polarized even at its
equilibrium geometry, and the cluster structures are highly asymmetri
c, demonstrating that the localizing solvation forces are able to over
come the delocalizing chemical bonding interactions. The pathways for
vibrational relaxation are also found to be distinctly different in th
e flexible and hyperflexible solvent. (C) 1997 American Institute of P
hysics.