Structures, charge distributions, and dynamical properties of weakly bound complexes of aromatic molecules in their ground and electronically excited states.

摘要

Complexes or clusters are non-covalently bound assemblies of two or more molecules that are held together by hydrogen bonding, van der Waals interactions, and other weak forces. The derived values of the rotational constants can be used to determine the structures of such species, in both their ground and electronically excited states. Some species exhibit different structures in the two states, owing to photon-induced changes in their electronic distributions. Evidence for the motion of one species relative to another along some intermolecular coordinate also is observed in some cases. We describe the application of these techniques to nitrogen and water complexes of p-difluorobenzene and Ar and water complexes of indole and azaindole, as models of hydrophobic and hydrophilic interactions. These studies have provided detailed information about how the electronic charge distributions of the species interact, how the structures of the individual species are modified when they interact, and how the properties of the complex are different from its component parts.