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

Hydrogen bonded rhodanine center dot center dot center dot(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 omega B97XD functionals. Calculation at MP2/CBS level indicates the formation of N - H center dot center dot center dot 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.

Automated summary

Hydrogen bonded rhodanine complexes involving oxygen, sulfur, and selenium were studied using quantum chemical calculations. The most stable structure was found to be N - H hydrogen bonded in all cases. Methyl substitution enhanced the hydrogen bond strength and demonstrated selenium's strong donor ability in the studied systems.