Vibrational Spectrum of Trisdimethylaminocyclopropenium Perchlorate

Infrared spectrum in the region 4000–100 cm−1 and Raman spectrum of trisdimethylaminocyclopropenium perchlorate (1) have been measured. Band assignments have been made on the basis of normal coordinate analysis and deuteration of the methyl groups. Remarkable stabilization of cyclopropenium ion due to the peripheral amino groups is attributed to a marked delocalization of the positive charge of the ring on the amino groups through conjugation. Peculiar electronic structure of trisaminocyclopropenium ion is explained in terms of its vibrational spectrum.