Thiophene-containing thiolato dimers, oxygen inserted Cu(II) complex, crystal structures, molecular docking and theoretical studies

Abstract

Reactions of n-butyl- and n-octyl-thiophene with CS2 at 0 °C resulted in thiolate dimers 1 and 2, respectively. The reaction of 1 with Cu(NO3)2·3H2O in methanol under ambient reaction conditions yielded monomeric [CuII{(n-C4H9(C4H2S)CS2O}2] (3). 1 and 3 were authenticated by their single-crystal X-ray crystal structures. Crystal structure of 3 revealed cleavage of the S-S bond of 1 followed by insertion of O-atom, forming a new five-membered Cu–O–S–C–S metallacycle. 1, 2, and 3 were further investigated for their bioactivity through molecular docking with nine different proteins having medicinal implications. Molecular docking of 1, 2 and 3 revealed considerable interaction with different proteins viz. cancer protein Tankyrase 2, influenza viral protein Polymerase subunit PAC–PB1N complex (H5N1), Polymerase subunit PA endonuclease (H1N1), Polymerase subunit PAn Apo(avian influenza), and FTSZ (Bacillus subtilis). Comparatively, 1 has promising application in therapeutics as compared to 2 and 3 based on its inhibitory constant and binding energy. Density functional theory calculations were performed to better understand the bonding of complex using MO diagram in 1–3. Moreover, TDDFT calculations were performed to facilitate the assignment of electronic transitions of UV–Vis spectra.