Protonation of benzimidazoles and 1,2,3-benzotriazoles – Solid-state linear dichroic infrared (IR-LD) spectral analysis and ab initio calculations

IR-LD spectroscopic data obtained by the orientated solid samples as a suspension in a nematic liquid crystal of 1-hydroxy-1,2,3-benzotriazole, 2-methyl-, 2-acetonitrilebenzimidazoles and their protonated salts have been presented. The stereo-structures have been predicted and compared with theoretical ones. The IR-characteristic bands assignments of all molecule systems have been achieved.