Infrared Spectra of Solid and Matrix-Isolated (CH3)3N, (CD3)3N, and (SiH3)3N

The argon-matrix infrared spectra of (CH3)3N, (CD3)3N, and (SiH3)3N are used to deduce a more complete assignment of the fundamental vibrational modes of these molecules than has previously been possible. Evidence is presented in support of a C3v rather than C3h point-group symmetry for trisilylamine. Barriers to internal rotation are calculated from the observed asymmetric torsional fundamentals of (CH3)3N in the solid and matrix phases and of (CD3)3N in the gaseous phase.