Synthesis, characterization and antimicrobial activity of some nickel, cadmium and mercury complexes of 5-methyl-3yl-N-(2′-methylthiophenyl)-methyleneimine, (MPzOATA) ligand

S.M. is thankful to the U.G.C., Govt. of India for providing financial support in the form of fellowship (videUGC Award No.: File No. 17-81/2008 (SA-I) dated: 04.1.2011). The financial support received from the University of Kalyani in the form of Personal Research Grant is thankfully acknowledged.Abstract Herein, we report the syntheses and structures of Ni(II) complexes, [Ni(MPzOATA)2] (Cl) (PF6) ( I ), [Ni(MPzOATA)2](ClO4)2.CH3CN (II) & [Ni(MPzOATA)2](BF4)2.H2O ( III ); Cd(II) complex, [Cd(MPzOATA)Cl2]2 ( IV ) and a Hg(II) complex, [Hg(MPzOATA)Cl2] ( V ), of a pyrazole based ‘NNS’ donor ligand, 5-methylpyrazole-3yl-N-(2′-methylthiophenyl)methyleneimine, (MPzOATA). The complexes are characterized byelemental analyses,electronic, IR, 1H NMR (only for IV & V ) spectral parameters, conductivity and fluorescence measurements. X-ray crystallographic data of the complexes reveal that the Ni(II) complexes have NiN4S2 octahedral coordination, one of them is a mixed-anion complex having Cl− and PF6− as counter anions; the Cd(II) complex is a chloro bridged binuclear complex with octahedral coordinationenvironment aroundeach metal centre, while the Hg(II) complex is a square pyramidal one. Among the reported complex species, the Ni(II) complexes are non-fluorescent, while the Cd(II) and Hg(II) complexes can be used as potential photoactive materials as indicated from their characteristicemission properties. The reported complexes are screened for their antimicrobial activities against some Gram positive and Gram negative microbial strains, and they are found to be potential antimicrobial agents in broad spectrum against both Gram positive and Gram negative bacteria.PostprintPeer reviewe

Synthesis, characterization and antimicrobial activities of Co(III) and Ni(II) complexes with 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2) : X-ray crystallography and DFT calculations of [Co(MPzNHex2)2]ClO4·1.5H2O (I) and [Ni(HMPzNHex2)2]Cl2·2H2O (II)

Manan Saha is thankful to the U.G.C., Govt. of India for providing financial support in the form of Rajiv Gandhi National Fellowship (Number and date of award letter: F1-17.1/2013-14/RGNF-2013-14-SC-WES- 51398/(SA-III/Website); 06/02/2014). N.C. Saha is thankful to the University of Kalyani for financial assistance received in the form of Personal Research Grant.A new pyrazole containing ligand, 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2), and a host of its cobalt(III) and nickel(II) complexes, [Co(MPzNHex2)2]X·mH2O and [Ni(HMPzNHex2)2]X2·nH2O (X= Cl, Br, ClO4, BF4 and NO3; m = 0 for Cl, Br, BF4 & NO3 and 1.5 for ClO4; n = 0 for Br, ClO4, BF4 & NO3 and 2 for Cl), respectively, have been synthesized and characterized by elemental analyses, magnetic measurements (polycrystalline state), 1H NMR (for the ligand and its Co(III) complexes), electronic and IR spectral parameters. All the reported Co(III) and Ni(II) complexes are cationic in nature and behaving as 1:1 and 1:2 electrolytes, respectively, in MeOH. Electronic spectral data of the complexes categorize them as havingdistorted octahedral coordination geometry. IR spectral features (4000-/450 cm-1) specify a monodeprotonated / neutral tridentate (NNS) function of the ligand, HMPzNHex2 coordinating to the Co(III) / Ni(II) via the pyrazolyl (tertiary) ring nitrogen, azomethine nitrogen and thiolato / thioketo sulfur atom. 1H NMR spectral data (in CDCl3 at 400 MHz) for the primary ligand and those of its Co(III) complexes are in agreement with the proposition of bonding sites evidenced from IR data. The single crystal x-ray data of I (C2/c (#15); monoclinic) and II (P-1 (#2); triclinic) have confirmed a CoN4S2 and a NiN4S2 octahedral coordination, respectively. The pair of monoprotic / neutral coordinating ligands is more or less orthogonal to each other in the complex species. The data obtained from DFT calculations are reasonably in agreement with the UV-Vis spectral assignment and the structures of the complex species. Although the ligand and the tested metal ion complexes are capable of inhibiting microbial growth, the cobalt complexes can be promoted as better antimicrobial agents.PostprintPeer reviewe

Synthesis and characterization of two Cu(II) complexes with a new pyrazole-based Schiff base ligand: crystallography, DNA interaction and antimicrobial activity of Ni(II) and Cu(II) complexes

<p>Reaction of Cu(II) nitrate with a new pyrazole-based Schiff base ligand, 5-methyl-3-formylpyrazole-N-(2′-methylphenoxy)methyleneimine (MPzOA), afforded two types of Cu(II) complexes at different reaction temperatures, [Cu(MP_zOA)(NO₃)]₂ (<b>1</b>) and [Cu(3,7,11,15-tetramethylporphyrin)(H₂O)](NO₃)₂ (<b>2</b>), reported together with a Ni(II) complex, [Ni(MPzOA)₂(H₂O)₂]Br₂ (<b>3</b>). The compounds are characterized by single crystal X-ray structure analyses along with several physico-chemical and spectral parameters. Complex <b>1</b> is authenticated as a bis(μ-pyrazolato)dicopper(II), while <b>2</b> is a porphyrinogen and <b>3</b> is a distorted octahedral complex. Structural analyses of the complexes reveal that <b>1</b> crystallized in monoclinic <i>P2</i>_<i>1</i><i>/n</i> space group while <b>2</b> and <b>3</b> crystallized in monoclinic <i>C2/c</i> space group. DNA-binding studies of the complexes have shown that the complexes interact with CT-DNA. DNA-cleavage studies with plasmid DNA have shown that <b>1</b> and <b>2</b> induce extensive DNA cleavage in the presence of H₂O₂ as an additive, whereas there is no change in degradation of super-coiled DNA by <b>3</b> in the presence of additive. The antimicrobial studies of the complexes against <i>Escherichia coli</i> DH5α bacteria strain indicated that all the complexes were capable of killing <i>E. coli</i> with different LD50 values.</p

Synthesis, characterization and antimicrobial activities of Co(III) and Ni(II) complexes with 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMP_zNHex₂):X-ray crystallography and DFT calculations of [Co(MP_zNHex₂)₂]ClO₄·1.5H₂O (I) and [Ni(HMP_zNHex₂)₂]Cl₂·2H₂O (II)

A new pyrazole containing ligand, 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2), and a host of its cobalt(III) and nickel(II) complexes, [Co(MPzNHex2)2]X·mH2O and [Ni(HMPzNHex2)2]X2·nH2O (X= Cl, Br, ClO4, BF4 and NO3; m = 0 for Cl, Br, BF4 &amp; NO3 and 1.5 for ClO4; n = 0 for Br, ClO4, BF4 &amp; NO3 and 2 for Cl), respectively, have been synthesized and characterized by elemental analyses, magnetic measurements (polycrystalline state), 1H NMR (for the ligand and its Co(III) complexes), electronic and IR spectral parameters. All the reported Co(III) and Ni(II) complexes are cationic in nature and behaving as 1:1 and 1:2 electrolytes, respectively, in MeOH. Electronic spectral data of the complexes categorize them as havingdistorted octahedral coordination geometry. IR spectral features (4000-/450 cm-1) specify a monodeprotonated / neutral tridentate (NNS) function of the ligand, HMPzNHex2 coordinating to the Co(III) / Ni(II) via the pyrazolyl (tertiary) ring nitrogen, azomethine nitrogen and thiolato / thioketo sulfur atom. 1H NMR spectral data (in CDCl3 at 400 MHz) for the primary ligand and those of its Co(III) complexes are in agreement with the proposition of bonding sites evidenced from IR data. The single crystal x-ray data of I (C2/c (#15); monoclinic) and II (P-1 (#2); triclinic) have confirmed a CoN4S2 and a NiN4S2 octahedral coordination, respectively. The pair of monoprotic / neutral coordinating ligands is more or less orthogonal to each other in the complex species. The data obtained from DFT calculations are reasonably in agreement with the UV-Vis spectral assignment and the structures of the complex species. Although the ligand and the tested metal ion complexes are capable of inhibiting microbial growth, the cobalt complexes can be promoted as better antimicrobial agents

Synthesis, characterization and antimicrobial activity of some nickel, cadmium and mercury complexes of 5-methyl-3yl-N-(2′-methylthiophenyl)-methyleneimine, (MPzOATA) ligand (dataset)

CCDC 1004238 CCDC 903321 CCDC 965608 CCDC 1048324 CCDC 104833