Infrared multiphoton dissociation spectrum of CF 3Mn (CO) 4I −

Abstract

An IR multiphoton dissociation spectrum of CF 3Mn(CO) 3I −has been obtained using Fourier transform ion cyclotron resonance spectroscopy combined with a line-tunable CW CO 2 laser in the 925–1085 cm −1 wavelength range. The trifluoromethyl group in the anion shows two absorption maxima at 1055 and 975 cm −1, which correspond to a C F stretch of A 1- and E-type symmetry respectively. From comparisons of the ligand effect on the stretching force constant of CO in place of CF 3 in cis and trans isomeric CF 3Mn (CO ) 4I − ions, it is suggested that a cis isomer is responsible for the observed C F stretching frequencies.