THE HINDERING OF THE INVERSION MOTION IN THE VANDERWAALS ANILINE-AR-NCLUSTERS - 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 unders tand the influence of the intramolecular inversion mode on the static properties (rotational constants). The effect of deuteration of the am ino group in the chromophore (C6H5NH2 or C6H5ND2) on the rotational co nstants of the complexes has been evaluated. The results are in good a greement with recent experimental values [W.E. Sinclair and D. W. Prat t, J. Chem. Phys. 105, 7942 (1996)]. In the ground electronic state S- 0, calculations show that the -NH2 (or -ND2) plane of the aniline mole cule tends to be blocked on the same side as the argon atom in the com plex. 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 lea st one argon atom bound in a site near the nitrogen atom. (C) 1998 Ame rican Institute of Physics.