The use of the monoanionic Schiff base ligand (E)-4-(2-hydroxybenzylideneamino)-2,3-dimethyl-1- phenyl-1,2-dihydropyrazol-5-one in transition (Co, Ni and Cu) coordination chemistry yields mono-, tetraand pentanuclear coordination clusters (CCs) with different structural motifs. An organic transformation occurs in the ligand in the Cu compound for which theoretical studies are presented. Solution studies, topological issues, and magnetic studies are discussed.

Two 1H-imidazol-4-yl-containing ligands 1,3-di(1H-imidazol-4- yl)benzene (L1 ) and 4,4′-di(1H-imidazol-4-yl)biphenyl (L2 ) were employed to react with corresponding metal salt together with varied carboxylate ligands under hydro- and solvothermal conditions, and six new metal−organic frameworks (MOFs) [Cd(L1 )(oba)]·DMF (1), [Ni3(L1 )2(BPT)2(H2O)4] (2), [Zn2(L1 )2- (HBPT)2]·H2O (3), [Ni(L1 )(BPTC)0.5(H2O)2] (4), [Ni2(μ2-O)(L2 )3(Hoba)2- (H2O)2] (5), and [Ni2(L2 )3(BPTC)(H2O)2]·6H2O (6) [H2oba = 4,4′-oxybis- (benzoic acid), H3BPT = biphenyl-3,4′,5-tricarboxylic acid, H4BPTC = biphenyl3,3′,5,

We are reporting a novel azo-azomethine ligand, HL and its complexes with Cu(II) and Fe(III) ions. The ligand and its complexes are characterized by various physico-chemical techniques using C,H,N analyses, FT-IR, 1H-NMR, ESI-MS and UV-Vis studies. TGA analyses reveal complexes are sufficiently stable and undergo two-step degradation processes. The redox behavior of the complexes was evaluated by cyclic voltammetry.

A tetradentate Schiff base ligand, L (L = N,N′-bis(1-(2-pyridyl)ethylidene)-2,2-dimethylpropane-1,3-diamine) was used in the preparation of a new mononuclear Zn(II) complex, [Zn(L)Cl]. The complex was structurally investigated by elemental analyses, spectroscopic studies and single crystal X-ray crystallography. Furthermore, to obtain insights into the structure, the ground state geometry of zinc complex cation was examined by dispersion corrected DFT method i.e. B3LYP-D3 within unrestricted scheme.

Molecular mechanism suggests that the incorporation of an antioxidant organic moiety to chromium will be a sound strategy for the synthesis of safer and more effective hypoglycemic compounds. Two Schiff base ligands were derived by condensation of isonicotinyl hydrazide with salicylaldehyde/o-hydroxyacetophenone which further yield four novel chromium(III) complexes of types [Cr(L)Cl2(H2O)] and [Cr(L)2]Cl. The ligands and complexes were characterized by analytical and spectroscopic techniques.

A new derivative of dioxouranium(VI) salen complex, [UO2(L)(pyridine)], where [L = N,N0 -Bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine] is synthesized and characterized by elemental analysis (C, H, N), FT-IR, ESI-MS spectrometry, UV/Vis, fluorescence, 1 H and 13C NMR spectroscopy and thermal gravimetric (TG) study. Furthermore, the single crystal X-ray diffraction measurements of the complex were carried out at 100 and 273 K.

A novel series of complexes of the type, [ML2].nH2O, [where L ¼ 2-(a-methyl salicylidenee20 -imino) aminobenzo thiazole (HMAB), 2-(a-phenyl salicylidenee20 -imino) aminobenzo thiazole (HPAB), 2-(oVanillidenee20 -imino) amino benzothiazole (HVAB)] have been reported. These Schiff bases and their transition metal complexes were fully characterized by several physico-chemical and spectral techniques, which revealed the tridentate chelation of ligand. The DFT calculations of these reported compounds were made to obtain bonding inside the structure by GAUSSIAN 03 programme platforms.

A novel mononuclear platinum complex with N2O2 donor atoms was synthesized from the ligand, [N,N′-bis(3- methoxysalicylidene)-2,2-dimethylpropane-1,3-diamine], H2L. The complex was characterized by microanalysis (C, H, N), spectroscopic studies and single crystal X-ray crystallography. The TGA study revealed that the complex degraded in two distinct steps. The effect of the platinum complex was examined by exposing the synthesized complex to rat embryonic hippocampal neurons.