This paper reports the syntheses, crystal structures and magnetic properties of Mn(III) hexadentate Schiff base complexes [Mn(4-OH-sal-N-1,5,8,12)]NO3(1) [Mn(4-OH-sal-N-1,5,8,12)]ClO4(2), where (4-OH-sal-N-1,5,8,12)2? (4,4?-((1E,13E)-2,6,9,13-tetraazatetradeca-1,13-diene-1,14-diyl)bis(3-methoxyphenol) is a new hydroxyl-substituted ligand. The introduction ligand induces more hydrogen bonding in...

The reactions of [(thf)2TiCl4] with sodiated 2,2’-bis[2-hydroxy-3,5-di(tert-butyl)benzylideneamino]-1,1’-biphenyl (1 a) and 2,2’-bis[2-hydroxy-3,5-di(tert-butyl)benzylideneamino]-4,4’-dimethyl-1,1’-biphenyl b) yield the corresponding Ti complexes 2 a b. Similarly, 1 reacts [(thf)2ZrCl4] to Zr derivative 3. For a, mixture cis-β trans isomers were observed in solution whereas congener exclusively...

The hexadentate, and ditopic ligand 2,5-bis([2,2']bipyridin-6-yl)pyrazine yields a chiral, tetrameric, square-shaped, self-assembled species upon complexation with Fe2+ ions. The racemate of this complex was resolved with antimonyl tatrate as the chiral auxiliary. The purity of the enantiomer was determined by NMR spectroscopy, by using a chiral, diamagnetic shift reagent, and by circular dichr...

Thirtyfive siderophore producing fungi were categorized for their hydroxamate, catecholate or carboxylate nature by chemical and bioassays. Out of 35 fungi, 30 were hydroxamates and 5 showed carboxylate nature. However, none of the fungi produced catecholate type of siderophores. Eighteen out of 29 fungi were trihydroxamate and the rest 11 fungi were dihydroxamates. Twenty-three fungi were hexa...

Three ferrous/ferric complexes of a N6 hexadentate ligand, N,N,N',N'-tetrakis(2-benzimidazolyl-methyl)ortho-diamine-trans-cyclohexane (ctb), [Fe(II)(ctb)](ClO(4))(2).EtOH (), [Fe(III)(OEt)(Hctb)](ClO(4))(3).EtOH (), and [Fe(III)(OMe)(Hctb)](ClO(4))(3).3MeOH.4.5H(2)O (), were synthesized and characterized as models of lipoxygenase. The lipoxygenase activities of the complexes were checked and th...

The ligands tris[3-(2-pyridyl)pyrazol-1-yl]hydroborate (L1, potentially hexadentate) and bis[3-(2-pyridyl)pyrazol-1-yl]dihydroborate (L2, potentially tetradentate) have been used to prepare ternary lanthanide complexes in which the remaining ligands are dibenzoylmethane anions (dbm). [Eu(L1)(dbm)2] is eight-coordinate, with L1 acting only as a tetradentate chelate (with one potentially bidentat...

A novel interesting hexadentate dibasic N(2)S(2)O(2) donor Schiff base ligand, H(4)dcsalpte, was synthesized by the condensation of 3-formylsalicylic acid and 1,2-di(o-aminophenylthio)ethane and characterized. The reactions of the ligand with different metal(II/III)salts under varied reaction conditions afforded a series of metal complexes. The ligand, H(4)dcsalpte, behaves either as a dibasic ...

In this review we report on the enantiomerization of tetrahedral racemic-[(NH4)4∩{Mg4(L1)6}] monitored by means variable temperature (VT) 1H NMR spectroscopy. The enantiotopization diastereotopic protons is due to simultaneous Bailar twists at four octahedrally coordinated magnesium centres, synchronized with atropisomerization six edge-bridging ligands (L1)2-.The VT spectrum meso-[In4(L2)4] co...

Multidentate Schiff base ligands derived from a selection of biphenyl- and terphenyl polyamines were synthesized, their reactivity towards divalent (Ni, Cu, Zn, Cd) trivalent (Co, Y, Lu) metals was studied by single-crystal X-ray diffraction analysis, NMR spectroscopy, UV/Vis spectroscopy for the Cu(II) complexes. Large variations in resulting complexes observed based on relative position amine...