MATRIX-ISOLATION FTIR AND AB-INITIO STUDY OF COMPLEXES BETWEEN FORMIC-ACID AND NITROGEN

The structure, energetics, and infrared spectra of nitrogen complexes of formic acid and its deuterated analogs have been investigated. Both FTIR matrix isolation technique and ab initio molecular orbital calcu lations have been employed. Two minima on the complex potential energy surface were found. One complex minimum resembles an almost linear hy drogen bond and the other minimum is directed to the hydroxyl oxygen l one electron pairs. The calculations and experimental results indicate substantial perturbations in the fundamental vibrational modes upon t he complexation. Good agreement between the observed and the calculate d complexation shifts on the vibrational fundamentals of the most stab le species is obtained. Mostly affected are the modes connected with t he complexation sites, e.g. the O-H stretching and torsional modes. Th e observed complex band structures and locations display the shape of the potential responsible for the 1:1 interaction.