The hindering of the inversion motion in the van der Waals aniline-Arn clusters:: An adiabatic molecular dynamics simulation for n=1-3

An adiabatic quantum molecular dynamics simulation has been performed for the van der Waals clusters aniline-Ar-n (with n = 1 - 3) to understand the influence of the intramolecular inversion mode on the static properties (rotational constants). The effect of deuteration of the amino group in the chromophore (C6H5NH2 or C6H5ND2) on the rotational constants of the complexes has been evaluated. The results are in good agreement with recent experimental values [W.E. Sinclair and D. W. Pratt, J. Chem. Phys. 105, 7942 (1996)]. In the ground electronic state S-0, calculations show that the -NH2 (or -ND2) plane of the aniline molecule tends to be blocked on the same side as the argon atom in the complex. On the other hand, for larger clusters (aniline-Ar-2 and aniline-Ar-3), it appears that the -NH2 (or -ND2) group is more localized on the side opposite to the argon atoms for the isomers containing at least one argon atom bound in a site near the nitrogen atom. (C) 1998 American Institute of Physics.