Savit Andotra

Synthesis, spectroscopic, DFT and in vitro biological studies of vanadium(III) complexes of aryldithiocarbonates

Vanadium(III) tris(dithiocarbonates), [(ROCS2)3V] (R=o-, m-, p-CH3C6H4 and 4-Cl-3-CH3C6H3) and donor stabilized addition complexes [(ROCS2)2V(Cl)·L] [L=NC5H5 or P(C6H5)3] were synthesized and characterized by elemental analyses, IR, mass, TGA/DTA, SEM magnetic susceptibility and heteronuclear NMR (1H, 13C and 31P) spectroscopic studies. The cytotoxicity of the complexes was measured in vitro using the cultivated human cell lines. In addition, the antioxidant activities of the ligands and its vanadium complexes were also investigated through their scavenging effect on DPPH radicals. The antimicrobial activity of ligands and some complexes has been conducted against three bacterial strains and fungus. The density functional theory (DFT) calculations of ligands and vanadium complexes were performed by the DFT/B3LYP/LANL2DZ method to obtain the optimized molecular geometry, vibrational frequencies, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), thermodynamic properties and various other quantum-mechanical parameters.

Syntheses, Characterization, Thermal, and Antimicrobial Studies of Lanthanum(III) Tolyl/Benzyldithiocarbonates

Lanthanum(III) tris(O-tolyl/benzyldithiocarbonates), [La(ROCS2)] (R = o-, m-, p-CH3C6H4 and C6H5CH2), were isolated as yellow solid by the reaction of LaCl3 ·7H2O with sodium salt of tolyl/benzyldithiocarbonates, ROCS2Na (R = o-, m-, p-CH3C6H4 and C6H5CH2), in methanol under anhydrous conditions in 1 : 3 molar ratio. These complexes have formed adducts with nitrogen and phosphorus donor molecules by straightforward reaction of these complexes with donor ligands, which have the composition of the type [La(ROCS2)3 ·nL] (where n = 2, L = NC5H5 or P(C6H5)3 and n = 1, L = N2C12H8 or N2C10H8). Elemental analyses, mass, IR, TGA, and heteronuclear NMR (1H, 13C and 31P) spectroscopic studies indicated bidentate mode of bonding by dithiocarbonate ligands leading to hexacoordinated and octacoordinated geometry around the lanthanum atom. Antimicrobial (antifungal and antibacterial) activity of the free ligands and some of the complexes have also been investigated which exhibited significantly more activity for the complexes than the free ligands.

First Donor-Stabilized Complexes of Manganese(II) with Disubstituted diphenyldithiophosphates: synthesis, characterization, biological, and X-ray Analysis

GRAPHICAL ABSTRACT Abstract The complexes [{(ArO)2PS2}2Mn(NC5H5)2] (1–4) [(Ar = 2,4-(CH3)2C6H3 (1), 2,5-(CH3)2C6H3 (2), 3,4-(CH3)2C6H3 (3), and 3,5-(CH3)2C6H3) (4)] have been isolated in aqueous medium and characterized by mass spectrometer, IR, magnetic susceptibility, and single crystal X-ray analyses. The complex [{(2,4-(CH3)2C6H3O)2PS2)}2Mn(NC5H5)2] (1) crystallizes in the monoclinic space group P21/n as a monomer with a basic core of the four-membered ring [MnS4]. The octahedral sphere of the Mn atom is completed by donation from the nitrogen atoms of the two pyridine rings and four sulfur atoms of the dithio moiety. The thermal gravimetric analysis of the complex (1) revealed the end product as MnS. Screening of the ligands and complexes against the fungus Fusarium oxysporum has indicated potential antifungal activity.

Synthesis, Spectral, Thermal, Electrochemical, and Biocidal Activity of Tolyl/Benzyl Dithiocarbonates of Zinc(II)

Tolyl/benzyl dithiocarbonates of zinc(II) [(CH3C6H4 and C6H5CH2OCS2)2Zn] have been synthesized in 1 : 2 molar ratio by the reaction of zinc chloride, ZnCl2, with sodium salts of tolyl/benzyl dithiocarbonates CS2Na, in aqueous medium. These complexes were further reacted with nitrogen and phosphorous donor ligands to obtain donor stabilized complex of the type [[(CH3C6H4 and C6H5CH2)OCS2]2Zn.nL], (L = Bipy, Phen for and PPh3, Py for ). These complexes were characterised by elemental analysis, mass, IR, and NMR (1H, 13C, and 31P) spectroscopies. The thermal analysis (TGA/DTA), cyclic voltammetry, and SEM have also been done. Distorted tetrahedral and octahedral geometries around the Zn(II) metal are proposed. These complexes have depicted potential antibacterial and antifungal activity.

Chromium(III) complexes of dimethyl diphenyldithiophosphates: Synthesis, characterization, and antibacterial studies

GRAPHICAL ABSTRACT ABSTRACT Dimethyl diphenyldithiophosphate complexes of Cr(III), [{(ArO)2PS2}3Cr] [Ar = 2,4-(CH3)2C6H3 (1), 2,5-(CH3)2C6H3 (2),3,4-(CH3)2C6H3 (3), and 3,5-(CH3)2C6H3 (4)], have been synthesized and structurally characterized by IR, heteronuclear NMR (1H, 13C, and 31P) spectroscopic and single crystal X-ray analyses. The crystal structure of complex 4 reveals mononuclear units with the Cr(III) centre chelated in bidentate fashion by six S atoms of the three diphenyldithiophosphate ligands to form octahedral geometry. The main core of the system comprised of four membered (CrS2P)3 heteroatomic ring and Cr(III) center. The ligands and complexes were evaluated for their antibacterial potential against six bacterial strains (K. pneumoniae, E.coli, P. aeruginosa, B. subtilis, S. aureus, and S. typhimurium). The metal derivatives of diphenyldithiophosphate ligands were found to be more active against the bacterial strains as compared to the free ligands.

Synthesis, characterization and single crystal x-ray analysis of a complex of iron(II) bis(2,4-dimethylphenyl)dithiophosphate with 4-ethylpyridine

Complex of iron(II) bis(2,4-dimethylphenyl)dithiophosphate with 4-ethylpyridine [{(2,4- (CH3)2C6H3O)2PS2}2Fe{NC5H4(C2H5)-4}2] is synthesized and characterized by elemental analysis, magnetic moment, IR spectroscopy and single crystal X-ray analysis. Complex crystallizes in the monoclinic sp. gr. P21/n, Z = 2. Crystal structure consists of mononuclear units with Fe(II) ion chelated by four S atoms of the two diphenyldithiophosphate ligands in bidentate manner. N atoms from two 4-ethylpyridine ligands are axially coordinated to the Fe(II) atom leading to an octahedral geometry.