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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.

Drug resistance in pathogens is a growing global health problem. The development of new drugs is a risky, time-consuming, and expensive process, since only a few got final approval. Organometallic compounds attracted attention due to their promising anticancer activities. In this study, four cyclometallates containing ruthenium and rhodium ions were synthesized from two phenolic azo ligands. These molecules were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility, FT-IR, mass, electronic,1H,13C{1H}, and31P{1H} NMR spectral studies. The general formula for the complexes istrans-[M(PPh3)2(Cl)(L)], where M = Rh or Ru, PPh3 = triphenylphosphine, and L = phenolic azo ligand. All the complexes possess prominent antibacterial activity againstEscherichia coliandMycobacterium tuberculosisas compared to market drugs. The interactions of rhodium derivatives with plasma–protein were also studied. Cyclometalation of a pendant aromatic ring is an example of C–H bond activation. Organometallic compounds were biologically potent and may be helpful for pharmaceutical industries for biological targets. [ABSTRACT FROM PUBLISHER]

Six complexes of Zn(II), Cd(II) and Hg(II) with sulphur containing Schiff base ligand, 1,4-bis((1 H-pyrrol-2-yl)methylene)thiosemicarbazide in 1:1 and 1:2 ratio has been synthesized. Complexes were characterized by molar conductance measurement, elemental analyses, FT-IR, 1H-NMR, and FAB/ESI-Mass. The complexes were used as a single source precursor for the synthesis of ZnS/CdS/HgS nanoparticles by their thermal decomposition in the presence of different surfactants. The precursor: surfactant ratio and temperature plays important role in determining the size of the nanoparticles. The size and morphology of nanoparticles has been ascertained by UV-Vis spectroscopy, XRD measurements and Transmission Electron Microscopy (TEM). Schiff base, complexes and nanoparticles were tested for antibacterial activity and MIC values against E. coli. The complexes were found more potent than the corresponding Schiff bases and nanoparticles. [ABSTRACT FROM AUTHOR]

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]

Complexes of MM'(SeCN)4, (M = Co2+, Ni2+; M' = Cd2+, Zn2+) with the Schiff base, N,N'-bis(2-chlorobenzylidene)ethylenediamine have been synthesized and characterized by elemental analysis, molar conductance, magnetic moment, FTIR, 1H-NMR, 13C{1H}-NMR and electronic spectroscopy. The catalytic activity of these complexes for hydrolysis of benzonitrile has been investigated. The complexes have also been investigated for antibacterial activity against Escherichia Coli and found to exhibit good growth inhibiton. [ABSTRACT FROM AUTHOR]