Synthesis, Photophysical, Antimicrobial Activity and In‐silico Study of Homoleptic Dithiocarbamate Complexes [MII{k2S^S‐S2CN(R)CH2C6H4OH}2] (R=2‐picolyl, 3‐picolyl; M=NiII, CuII, ZnII)

An array of mononuclear dithiocarbamate complexes [MII{k2S^S‐S2CN(R)CH2C6H4OH}2] (R=2‐picolyl, M=NiII 1, CuII 2, ZnII 3, R=3‐picolyl, M=NiII 4, CuII 5, ZnII 6); incorporating heterocyclic backbone were synthesised from (2‐hydroxybenzyl)(2‐picolyl)amine (HL1) and (2‐hydroxybenzyl)(3‐picolyl)amine (HL2) precursors. The formulation of these complexes was examined using various spectroscopic and analytical techniques (1H NMR, 13C NMR, FTIR, UV‐visible, Fluorescence, TGA/DTA) and further corroborated by DFT level calculation. Notably, precursors HL1 and HL2 exhibits maximum emission in the visible nm region (ca 502 and 408 nm) upon excitation of ultraviolet radiation at ~280 nm with concomitant Stokes shift ca 220 and 128 nm, respectively. The emission properties of these evidently suppressed after complexation with metal ions. Stability of 1–6 were determined by thermogravimetric analysis. The magnetic moment along with UV‐visible of 1–6 suggests square‐planar environment around NiII and CuII and tetrahedral environment around ZnII in 1–6 which is in accord with their optimized geometries. Compounds were screened for in‐ vitro antimicrobial activity against E. coli, P. aeruginosa, S. aureus, S. pyogenes, C. albicans, A. niger, A. clavatus by broth dilution method. Molecular docking study was performed to rationalize the results. This report encompasses on the synthesis of mononuclear dithiocarbamate complexes holding heterocyclic backbone and their examination by 1H NMR, 13C NMR, FTIR, UV‐visible, Fluorescence, TGA/DTA. Compounds are screened for in‐ vitro antimicrobial activity against E. coli, P. aeruginosa, S. aureus, S. pyogenes, C. albicans, A. niger, A. clavatus. In‐silico studies are performed to rationalize the results.