Intermolecular interactions of 4-pyrrolidino pyridine: a simulation study

Simulations of intermolecular interaction by the AM1 method have been performed. The hydrogen bonding complex between and 4-pyrrolidino pyridine (PP) and water molecules with 1:n complexes have been considered to investigate possible stable complex configurations and to calculate the stable interaction energy. These calculations confirm the influence of water molecules on twisting of the pyrrolidino group in ground state. The excited state simulation predicts that the energy minimized geometry of the PP molecule takes an almost sandwich like structure, confirming the formation of an intramolecular exciplex in the gas phase as well as in nonpolar or in weakly polar solvents in line with the experimental findings. (C) 1999 Elsevier Science B.V. All rights reserved.