0000000001314281
AUTHOR
Reena Singh
Hydrogen-atom and oxygen-atom transfer reactivities of iron(iv)-oxo complexes of quinoline-substituted pentadentate ligands
A series of iron(II) complexes with the general formula [FeII(L2-Qn)(L)]n+ (n = 1, L = F−, Cl−; n = 2, L = NCMe, H2O) have been isolated and characterized. The X-ray crystallographic data reveals that metal–ligand bond distances vary with varying ligand field strengths of the sixth ligand. While the complexes with fluoride, chloride and water as axial ligand are high spin, the acetonitrile-coordinated complex is in a mixed spin state. The steric bulk of the quinoline moieties forces the axial ligands to deviate from the Fe–Naxial axis. A higher deviation/tilt is noted for the high spin complexes, while the acetonitrile coordinated complex displays least deviation. This deviation from linear…
A Bis(mu-phenoxo)-Bridged Dizinc Complex with Hydrolytic Activity
The dinuclear complex [Zn2(papy)2]·2CH3OH [H2papy = N- (2-hydroxybenzyl)-N-(2-picolyl)glycine] was synthesized and characterized. The crystal structure of the complex reveals that both ZnII ions are pentacoordinate with distorted pentagonal bipyramidal coordination arrangements. The phenoxyl groups of each ligand bridge the two metal atoms, whereas each carboxylate of the ligand is terminally bound to one ZnII ion. Potentiometric studies of the ZnII:H2papy system in a methanol/water mixture show the existence of a mononuclear species at lower pH; but at a pH above 5, a dimeric species starts to dominate and transforms further into a bis(μ-phenoxo) bridged dizinc complex by deprotonation of …
High Turnover Catalase Activity of a Mixed‐Valence Mn II Mn III Complex with Terminal Carboxylate Donors
The neutral dimanganese(II,III) complex [Mn-2(BCPMP)-(OAc)(2)] [1; BCPMP3- = 2,6-bis({(carboxymethyl)[(1-pyridyl)-methyl] amino} methyl)-4-methylphenolato] has been synthesized and characterized. The complex contains two terminal carboxylate donors. Complex 1 was found to be an effective catalyst for the disproportionation of H2O2 with high catalytic rate and a turnover number of 7500, the highest turnover reported to date for a catalase mimic. The rates and TON were significantly higher than recorded for a dicationic dimanganese( II,III) counterpart ([Mn-2(BPBP)(OAc)(2)]center dot(ClO4)(2), 2; BPBP- = 2,6-bis{[bis(2-pyridylmethyl)amino]methyl}-4-butylphen-olato), which lacks the terminal c…
Iso-valence Co(II) and mixed-valence Co(II/III) tetranuclear complexes: Synthesis, structure, magnetic properties and DFT study
Abstract The reaction of Co(ClO4)2·6H2O with symmetrical N4O3 coordinating heptadentate ligand (H3L) in presence of triethylamine yielded cobalt(II) tetranuclear complexes [Co4(L)2](ClO4)2, 1. When the same reaction is carried out with sodium azide instead of triethylamine afforded tetranuclear mixed-valence Co(II/III) species, [Co4(L)2(μ1,3–N3)2](ClO4)2, 2. Here L3− is the deprotonated form of 2,6-bis[{{(1-hydroxy-2-methylpropan-2-yl)(pyridine-2-ylmethyl)}amino}methyl]-4-methylphenol. Complex 1 crystallizes in the cubic system, space group Fd-3c, with unit-cell parameters a = b = c = 43.320(5) A, Z = 48, whereas complex 2 crystallizes in the space group I41/a in the tetragonal crystal syst…
CCDC 927054: Experimental Crystal Structure Determination
Related Article: Mainak Mitra, Reena Singh, Monika Pyrkosz-Bulska, Matti Haukka, Elzbieta Gumienna-Kontecka, Ebbe Nordlander|2013|Z.Anorg.Allg.Chem.|639|1534|doi:10.1002/zaac.201300160
CCDC 1062123: Experimental Crystal Structure Determination
Related Article: Reena Singh, Matti Haukka, Christine J. McKenzie, Ebbe Nordlander|2015|Eur.J.Inorg.Chem.||3485|doi:10.1002/ejic.201500468