Co(II), Ni(II), Cu(II) and Zn(II) complexes of acenaphthoquinone 3-(4-benzylpiperidyl)thiosemicarbazone: Synthesis, structural, electrochemical and antibacterial studies. (25th September 2017)

• Record Type: Journal Article
• Authors: Kumar, Santosh; Hansda, Arti; Chandra, Angeera; Kumar, Ashish; Kumar, Mukesh; Sithambaresan, Maheswaran; Faizi, Md. Serajul Haque; Kumar, Vipin; John, Rohith P.
• Is Part Of: Polyhedron. Volume 134(2017)
• Page Start: 11
• Page End: 21
• Publication Date: 2017-09-25
• Subjects: UV–Vis UV–Visible -- ESI-MS electron spray ionization-mass spectroscopy -- EPR electron paramagnetic resonance -- HOMO highest occupied molecular orbital -- DFT density functional theory -- LUMO lowest unoccupied molecular orbital -- FLC friend erythroleukemia cells -- TBAP tetra butylammonium perchlorate -- DMF N, N-dimethylformamide -- DMSO dimethylsulfoxide -- MTCC microbial type culture collection; Thiosemicarbazone -- DFT studies -- Cyclic voltammetry -- EPR studies -- Antibacterial activity; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.05.055
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Four new complexes, viz, Co II L2, Ni II L2, Cu II L2 and Zn II L2, with acenaphthoquinone 3-(4-benzylpiperidyl)thiosemicarbazone were synthesized. The complexes were characterized by various methods such as elemental, mass, UV–Vis and NMR spectroscopy. The quantum chemical parameters of the compounds were obtained using DFT calculations and were correlated with their observed biological activity. The solid state structures of cobalt(ii) and nickel(ii) complexes were established by single crystal X-ray diffraction technique. The in vitro anti-bacterial activity indicate that the complexes show higher inhibitory activity against selected bacterial cultures E. coli, P. aeruginosa, B. subtilis, S. aureus and the anti- bacterial activity of nickel(ii) complex is found to be higher than the other three complexes investigated. Abstract: An interesting series of four complexes of acenaphthoquinone 3-(4-benzylpiperidyl) thiosemicarbazones (HL), with a general formula [Co II L2 ](1 ), [Ni II L2 ](2 ), [Cu II L2 ](3 ), and [Zn II L2 ](4 ), were prepared. The complexes were characterized by means of elemental analysis, IR, UV–Vis spectroscopy and ESI-MS methods. In all the complexes the ligand (HL) coordinate as a monobasic ligand in tridentate fashion. The crystal structure of the compounds1 and2 were determined by single crystal X-ray diffraction experiment. The geometry and bonding parameters of the compound3 were determined from EPR spectra. The g values of3, calculated from EPR at 77 K, indicate a rhombic coordination geometry about copper(II). The room temperature magnetic moment of the cobalt(II) complex1, indicate that it is in high spin state, while the nickel(II) complex, 2, is paramagnetic. The redox behavior of the ligand and its complexes were studied by cyclic voltammetry. The density functional theory (DFT) was used for geometry optimization, determination of HOMO and LUMO energies, HOMO–LUMO energy gap and dipole moment of the compounds. Antibacterial activity of the ligand and complexes1 –4, have been screened against two gram negative bacteria Escherichia coli, Pseudomonas aeruginosa and two gram positive bacteria Staphylococcus aureus and Bacillus subtilis. The electron micrograph images display damage to microbial cell wall upon treatment with the compounds.