New Vibrational Information on Simple Amides in Solution: A Case Study on GaCl3-Formamide Complexes

Abstract

IR and Raman measurements were carried out for GaCl3-formamide (FA) solutions, and comparisons with the Al3+ and Fe3+ chemistry are presented. Upshifts of both νCO and νCN modes of FA are observed, and analyses of the corresponding bands suggest different types of solvatocomplexes. The twisting mode (γHNH) of FA at 1190 cm−1, which is IR- and Raman-inactive, is activated only in the former upon coordination to high electrostatic potential ions. The spectral behavior exhibited in this region is shown for the first time in the literature and has helped in the understanding of the coordinated FA structure. The catalytic power of Ga3+ towards amide bond hydrolysis is also predicted for the first time using vibrational spectroscopy and may be useful for biological studies.