Structural and hydrogen-bonding properties of neat t-BuNH2 and its binary mixtures with CCl4, CHCl3 and DMSO

摘要

Many physicochemical features of substances are influenced by the inter-species interactions, most importantly hydrogen/halogen bonds (H-/X-bonds). In the present study, the structural and H-bonding characteristics of neat t-BuNH2 along with its binary mixtures with cosolvents CCl4, CHCl3 and DMSO-d(6) were investigated by ATR-FTIR and quantum chemical calculations. Excess absorption and two-dimensional correlation spectroscopies were used for further analysis of the obtained IR data. The results show that mixing CCl4 and CHCl3 with t-BuNH2 transform the dimer and the cyclic trimer of t-BuNH2 to monomer, with negligible effect of cross complexes on the spectral shapes in upsilon(N-H). However, as a strong H-bond acceptor, DMSO impacts the system in a significantly different manner. It develops strong H-bonds with t-BuNH2. In t-BuNH2-DMSO system, all the species of t-BuNH2 including dimer and monomer transform to complexes with DMSO. It was also found that all the H-/X-bonds identified between t-BuNH2 and cosolvents are non-covalent in nature with more contribution from electrostatic interactions. (C) 2020 Elsevier B.V. All rights reserved.