RAMAN SPECTRUM OF METHYLAMMONIUM CHLORIDE (CH3NH3,Cl) IN THE SOLID STATE AND IN SOLUTION

Abstract

Several workers have investigated the infrared spectrum of methylammonium chloride and yet its Roman spectrum in the solid state was hitherto unknown. As some alums containing this CH3N+H3 are known to be ferrorlectric and as the Raman spectrum of a-MAC can elulcidale the symmetry and magnitude of the crystal and effects on the vibrations of the CH3N+H3 ion, we are reporting here the new Raman data on a-MAC. The Raman shifts obierved in the room temperature crystalline phase are 54, 87, 184, 960, 1000, 1240, 1439, 1465, 2783,2626, 2904, 2963, and 3020 cm-1. An analysis of the spectrum leads us to conclude that the correlation coupling effect on the CH3N+CH3 ion is small. No line is observed in the indicator band region. The presence of intense Roman lines in the high frequency region have been attributed to a Frrmi resononce between the C- H - stretching frequency and the harmonic of C-H bending vibrarions.