Hydrogen bonded complexes of Rhodanine with H2X/CH3XH (X=O, S, Se)

Abstract Hydrogen bonded rhodanine⋅⋅⋅(H2X/CH3XH) complexes where X = O, S, Se has been investigated using quantum chemical calculations. The most stable conformer of rhodanine is chosen for the investigation of hydrogen bonded binary complexes. In each set, four different conformers are obtained. The interaction energies and geometries of the complexes have been investigated using Moller-Plesset (MP2) perturbation theory and density functional theory with B3LYP, mPW1PW91 and ωB97XD functionals. Calculation at MP2/CBS level indicates the formation of N   H⋅⋅⋅X hydrogen bonded structure as the most stable structure in all cases. Methyl group substitution in the interacting partner of the binary complexes lead to strengthening of hydrogen bond and flattening of potential energy surface for methanethiol and methyl selenol complexes. The donor ability of Se to form hydrogen bonds is well exhibited in the studied systems. The AIM and NBO calculation reveals the nature and strength of the hydrogen bonding in the binary complexes.