X-ray crystallographic investigation and biological activities of Ru(III) complexes containing Schiff base and triphenyl phosphine/arsine

N′-[(1E)-3-Bromo-5-chloro-2-hydroxybenzylidene]-4-tert-butylbenzohydrazide ethanol monosolvate

In the title compound, C₁₈H₁₈BrClN₂O₂·C₂H₆O, the hy­droxy group forms an intra­molecular O—H⋯N hydrogen bond, which influences the conformation of the Shiff base mol­ecule, where the two aromatic rings form a dihedral angle of 21.67 (8)°. Inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link two Shiff base mol­ecules and two solvent mol­ecules into a centrosymmetric heterotetra­mer. Weak inter­molecular C—H⋯O inter­actions link further tetra­mers related by translation along the a axis into chains.

Preparation, spectroscopy, EXAFS, electrochemistry and pharmacology of new ruthenium(II) carbonyl complexes containing ferrocenylthiosemicarbazone and triphenylphosphine/arsine

A new series of new hetero-bimetallic complexes containing iron and ruthenium of the general formula [RuCl(CO)(B)(EPh3)(L)] (where E=P or As; B=PPh3, AsPh3, py or pip; L=ferrocene derived monobasic bidentate thiosemicarbazone ligand) have been synthesized by the reaction between ferrocene-derived thiosemicarbazones and ruthenium(II) complexes of the type [RuHCl(CO)(B)(EPh3)2] (where E=P or As; B=PPh3, AsPh3, py or pip). The new complexes have been characterized by elemental analyses, IR, electronic, NMR (1H, 13C and 31P), EXAFS (extended X-ray absorption fine structure spectroscopy) and cyclic voltammetric techniques. Antibacterial activity of the new complexes has been screened against Escherichia coli, Vibrio cholerae, and Pseudomonas aeruginosa species.

N'-(5-Chloro-2-hydroxy-benzyl-idene)nicotinohydrazide

There are two independent Schiff base mol­ecules in the asymmetric unit of the title compound, C₁₃H₁₀ClN₃O₂. The dihedral angles between the benzene and pyridine rings are 12.8 (2) and 1.9 (2)° in the two mol­ecules. Intra­molecular O—H⋯N hydrogen bonds are observed. Mol­ecules are linked into centrosymmetric R⁴₄(26) motifs by N—H⋯O and N—H⋯N inter­actions.

4-Hydr-oxy-N'-(3,5-dichloro-2-hydroxy-benzyl-idene)benzohydrazide

In the title compound, C(14)H(10)Cl(2)N(2)O(3), the dihedral angle between the two benzene rings is 5.1 (2)°. The mol-ecule adopts an E configuration with respect to the C=N bond and an intra-molecular O-H⋯N inter-action is present. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.

Synthesis, spectroscopic characterization, electrochemical behaviour and antibacterial activity of Ru(III) complexes of 2-[(4-N,N'-dimethylaminophenylimino)-methyl]-4-halophenol

The reaction of the chelating Schiff base ligands 2-[(4-N,N'-dimethylaminophenylimino)-methyl]-4-X-phenol with [Ru(Cl)(3)(EPh(3))(3)]; (E=P or As); (X=Cl, Br or I) in the benzene afforded new stable ruthenium complexes of the general formula [Ru(Cl)(2)(EPh(3))(2)(L)] (L=anion of bidentate Schiff bases). The newly synthesized complexes were characterized using molar conductivity, spectral (UV-vis, FT-IR and EPR) and electrochemical studies. The molar conductance measurements proved that all these complexes are non-electrolytes. All complexes show strong d-d transition in the visible region. The coordination of imine nitrogen and phenolic oxygen of ligands to ruthenium metal was confirmed with the change in the IR stretching frequency values. The EPR spectral data showed that the complexes are paramagnetic with one unpaired electrons. The redox behaviour of the complexes have been investigated by the cyclic voltammetric technique. All the complexes display an irreversible reduction (Ru(III)/Ru(II)) in the range of -0.826 to -0.971V. In view of the biological activity, the ligands and the complexes were observed that all the complexes showed moderate activity. Also the antibacterial activity of the ligand increased on chelation with metal ion.

Structural and biological studies of mononuclear palladium(II) complexes containing N-substituted thiosemicarbazones

New complexes of Pd(II) with N-substituted thiosemicarbazone (1)-(3) have been synthesised and characterised by elemental analyses, IR, electronic, (1)H NMR spectroscopies. The electrochemical behaviour of the complexes has been tested by using cyclic voltammetry. The crystal structures of the complexes have been determined by single crystal X-ray diffraction technique. In all the complexes the thiosemicarbazone ligand is coordinated to palladium through ONS mode. The complex 1 crystallises in the monoclinic space group P2(1)/c with two molecules per unit cell, has the dimensions of a=9.4390(19)A, b=10.645(2)A, c=13.668(3)A, alpha=90 degrees , beta=91.43 degrees and gamma=90 degrees . The complex 3 crystallises in the monoclinic space group P2(1)/c with four molecules per unit cell, has the dimensions of a=14.119(3)A, b=11.155(2)A, c=18.503(4)A, alpha=90 degrees , beta=112.02 degrees and gamma=90 degrees . The new complexes have been tested for their antibacterial activity against various pathogenic bacteria. From this study, it was found out that the activity of the complex 2 almost reaches the effectiveness of the conventional bacteriocide Streptomycin.