Infrared Spectra and Vibrational Assignments of trans–CH3N–NH, CH3N–ND, CD3N–NH, and CD3N–ND

Abstract

Based on infrared spectra (4000–200 cm−1) of the gas phase, condensed phase (77°K), and nitrogen matrices (20°K) vibrational assignments for trans‐CH3N–NH, CH3N–ND, CD3N–NH, and CD3N–ND have been obtained. The assignments of the fifteen fundamentals of each molecule are well founded in experiment except for the provisional values for the torsional mode. For trans‐CH3N–NH the fundamentals are: (a′) 3127, 2992, 2925, 1559, 1457, 1435, 1382, 1120, 920, and 557 cm−1, (a″) 2988, 1430, 1140, 844, and ∼ 170 cm−1. Normal coordinate calculations are presented in support of these assignments and as a basis for further analysis of the published infrared spectra of the parent molecule, trans‐N2H2. It is shown that the spectra for N2H2, N2HD, and N2D2 can now be interpreted in a unified way