Hydrogen bonding type charge transfer interaction between thiols and amines

Abstract

The interactions between n-propylmercaptan (electron acceptor) and amines (electron donors), such as triethylamine (TEA), N-methylpiperidine (MP), ethyleneimine (EI), N-methylimidazole (MI) and pyridine (PD) are investigated by electronic absorption spectroscopy and n.m.r. measurements. The strength of the interaction is almost proportional to the values of the ionization potential of donor molecules and is also found to be very sensitive to the solvent polarity. We have performed m.o. calculations using the CNDO/2 approximation in order to obtain stable configurations of the ground states and to assign the charge transfer bands observed in these systems.