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Tailored reaction of Schiff base ligands with palladium(II) chloride and imidazole afford three complexes of formula [Pd(II)(L)(imdz)2]Cl, which are L = 2-((E)-(p-lylimino)methyl)-6-methoxyphenol (complex 1), 2-methoxy- -6-((E)-(phenylimine)methyl)phenol (complex 2) and 2-((E)-(4-chlorophenylimino) methyl)-6-methoxyphenol (complex 3). Compounds were characterized with elemental analysis, molar conductance, electronic spectroscopy, ESI-MS, FT-IR, TGA, 1H-NMR and 13C-NMR. Molecular structure and different quantum chemical parameters were calculated using the B3LYP basis set of density functional theory with the standard 6-311+G (d, 2p) level. The catalytic potential of 1-3 was examined over Heck-Mizoroki reaction and found in order of 1 > 2 > 3.

The Schiff base ligand, namely (7E)-N-benzylidene-2-styrylbenzenamine- 1,2-diamine-2,4-dihydroxy-phenol (L), was synthesized by condensation of 2,4-dihydroxybenzaldehyde with o-phenylenediamine. The reaction of the ligand with Fe(III), Co(II) and Ni(II) salts in an 1:1 ratio yielded three complexes (1–3). Different analytical tools, like elemental analysis, ESI-MS, UV–Vis, FT-IR, NMR and EPR spectroscopy, then molar conductivity and magnetic susceptibility spectra, were used to elucidate the structure of the ligand and complexes. Density functional theory calculation at the B3LYP/3- -211G++/LANL2DZ level of the theory has been carried out to optimize the geometry of the ligand and complexes. The tetradentate ligand has coordinated to metals through ONNO donors affording octahedral geometry. Complexes were studied for their oxygen-binding activity and free radical scavenging activities. Complexes 1 and 2, which contain Fe(IIl) and Co(II), displayed reversible oxygen binding activity. On the other hand, complex 3 fails to show oxygen binding. The order of antioxidant activity is: 3 > 1 > 2 > L.

In this study, a dinucleating spacer incorporating two 2-aminopyridine units has been used to prepare seven novel dinuclear compounds. These molecules were characterized by elemental analyses, conductivity measurements, magnetic susceptibility, FT-IR, FAB-Mass, electronic, 1H and 13C{1H}NMR spectral studies. The complex [{trans,mer-RuCl2(DMSO)3}2(μ-5,5'-methylenebis(2-aminopyridine))].2DMSO, 2 was also characterized through 1H-1H COSY NMR. There are mainly three different formulations; [{cis,fac-RuCl2(SO)3}2(μ-MBAP)].2SO; [{trans,mer-RuCl2(SO)3}2(μ-MBAP)].2SO and [{trans-RuCl4(SO)}2(μ-MBAP)]2- [X]2+; where SO = DMSO / TMSO; MBAP = 5,5'-methylenebis(2-aminopyridine) and [X]+ = [(DMSO)2H]+, Na+ or [(TMSO)H]+. The coordination was found through cyclic nitrogen of pyridine ring in octahedral environment for both metal centers. The chemical behivour of [{cis,fac-RuCl2(DMSO)3}2(μ-5,5'-methylenebis(2-aminopyridine))].2DMSO, 1 and 2 in aqueous solution with respect to time was observed by conductivity measurements and UV-vis spectrophotometer. All complexes were found to possess prominent antibacterial activity against Escherichia coli in comparison to Chloramphenicol and Gatifloxacin.

Synthesis and characterization of seven ruthenium (II) and ruthenium (III) chloro sulphoxide complexes with 1, 2, 3- benzotriazole are reported. Three different formulations exist: [cis,fac--RuCl2 (so) 3 (btz)]; [trans--RuCl (so) (btz)] and [trans--RuCl4 (so)(btz)] [X]+; where so=dimethylsulphoxide/ tetramethylenesulphoxide; btz = 1, 2, 3-benzotriazole and [X]+ = [(btz)H]+ or Na+. These complexes were characterized by elemental analysis, conductivity measurements, magnetic susceptibility, FT-IR, ¹H-NMR, C13{¹H}-NMR and electronic spectroscopy. Complexes were screened for their antibacterial activity and found more potent than 1, 2, 3-benzotriazole ligand and precursor ruthenium compounds against gram-negative bacteria Escherichia coli. All the samples were compared with antibiotic Chloramphenicol for reference. [ABSTRACT FROM AUTHOR]