Supersonic Molecular Jet Studies of Toluene-Helium and Toluene-Methane Clusters

摘要

The techniques of fluorescence excitation (FE), dispersed emission (DE), and 1- and 2-color time of flight mass spectroscopy (TOFMS) have been employed to study van der Waals clusters of toluene-helium (To1He) and toulene-methane (TolCH4) formed in a supersonic molecular jet. Spectral shifts for the toluene 1 A sub 1 to 1 B sub 2 transition have been characterized for TolHe1,2 and To1(CH4)1,2. The van der Waals stretching frequencies (V1) in the excited states of these clusters have been identified. The ground state stretch (V1) for TolHe has also been found; it is quite similar to the TolHe V1. The binding energies (Do) for Tol-He clusters lie between 75 and 90/cm and those for Tol-CH4 clusters lie between 533 and 739/cm. The coordination of a third solvent molecule to those clusters generates a broad spectrum whose shift is close to the limiting value for a large (X greater than) cluster. A comparison between these data and methane solution data is presented.