Oxidation of Alkylbenzenes with Cerium Complexes Containing a Tripodal Oxygen Ligand

2014 ◽  
Vol 2014 (35) ◽  
pp. 6097-6103 ◽  
Author(s):  
Xiao-Yi Yi ◽  
Guo-Cang Wang ◽  
Ho-Fai Ip ◽  
Wai-Yeung Wong ◽  
Lizhuang Chen ◽  
...  
Keyword(s):  
Oxygen Ligand

Crystal structures of nickel(II) and copper(Il)-Schiff-bases complexes with tetramic and tetronic acid subunits

1994 ◽  
Vol 209 (12) ◽  
Author(s):  
G. Reck ◽  
B. Schulz ◽  
A. Zschunke ◽  
O. Tietze ◽  
J. Haferkorn
Keyword(s):  
Complex Formation ◽  
Water Molecule ◽  
Crystal Structures ◽  
Schiff Bases ◽  
Water Molecules ◽  
Ligand Molecule ◽  
Tetragonal Pyramid ◽  
Space Group ◽  
Tetronic Acid ◽  
Oxygen Ligand

AbstractN,N′-ethylene-bis-(tetronic-acid-3-formiminato)-copper(II)/K1 crystallizes in space groupN,N′-ethylene-bis-(tetronic-acid-3-formiminato)-nikkel(II)/K2 crystallizes in space groupN,N′-ethylene-bis-(1,5,5-trimethyltetramic-acid-3-formiminato)-copper(II)/K3 crystallizes in space groupIn K1 and K3 copper is coordinated by two nitrogen and two oxygen atoms of the ligand molecule as well as by one water molecule on top of a tetragonal pyramid. In K2 two water molecules are included in the complex formation. These and two nitrogen as well as two oxygen ligand atoms form a nearly regular octahedron.

scholarly journals Multi-Electron-Transfer Catalysts Needed for Artificial Photosynthesis

2012 ◽  
Vol 1387 ◽  
Author(s):  
James Vickers ◽  
Hongjin Lv ◽  
Petro F. Zhuk ◽  
Yurii V. Geletii ◽  
Craig L. Hill
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Electron Transfer ◽  
Catalytic Activity ◽  
Induction Period ◽  
Water Oxidation ◽  
Fuel Production ◽  
Oxygen Ligand ◽  
Visible Light Driven ◽  
Simple Kinetic Model

ABSTRACTWe report a study on catalytic water oxidation by cobalt in oxygen ligand environments because such systems are as promising as any in the water oxidation component of solar fuel production. We have re-examined the catalytic activity of Co(II) in aqueous solution using either [Ru(bpy)3]3+ as a stoichiometric oxidant or in visible-light-driven reactions with persulfate as a sacrificial electron acceptor. In both systems a distinctive induction period is observed. A simple kinetic model is proposed that describes the experimental data well. The presence of an induction period is explained by relatively slow formation of the true catalyst from aquacobalt(II).

[Cp*Ir{P(O)(OMe)2}3]−, an iridium(III) phosphonate complex acting as a chelating oxygen ligand: synthesis and coordination chemistry

1993 ◽  
Vol 207 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Mario Scotti ◽  
Mauricio Valderrama ◽  
Pedro Campos ◽  
Wolfgang Kläui
Keyword(s):  
Coordination Chemistry ◽  
Oxygen Ligand ◽  
Ligand Synthesis

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. VI. Mixed Oligodentate-Aliphatic-Base/Oxygen Ligand Adducts

1996 ◽  
Vol 49 (1) ◽  
pp. 87 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Mixed Ligand ◽  
Metal Salts ◽  
Precise Description ◽  
Nitrogen Base ◽  
X Ray ◽  
Oxygen Ligand ◽  
Group 2 ◽  
Ligand Species

In the course of synthesizing oligodentate aliphatic nitrogen base adducts of Group 2 metal salts, a number of mixed- ligand species have been isolated with oxygen ligands , and characterized by room-temperature single-crystal X-ray studies. BaCl2.4en.H2O ≡[(en)4Ba(OH2)] Cl2 (1) is monoclinic, P 21/c, a 9.456(4), b 14.953(6), c 14.82(1) Ǻ, β 100.78(6)°, Z = 4 f.u ., R 0.043 for No 1862 independent 'observed' (I > 3σ(I)) diffractometer reflections. Ba -N range between 2.900(9) and 2.97(1) Ǻ, and Ba-O is 2.779(8) Ǻ in the nine-coordinate BaN8O environment. CaCl2.2dien.H2O ≡ [( dien )2Ca(OH2) Cl ] Cl (2) is monoclinic, P 21/c, a 10.808(4), b 11.999(4), c 15.71(1) Ǻ, β 123.58(4)°, Z = 4 f.u ., R 0.050 for No 3134; CaBr2.2dien.2H2O ≡ [( dien )2Ca(OH2)2] Br2 (3) is monoclinic, P 21/c, a 18.001(3), b 11.983(6), c 21.562(5) Ǻ, β 124.97(2)°, Z = 8 f.u ., R 0.045 for No 2858; CaBr2.2dien.2MeOH ≡ [( dien )2Ca( HOMe )2] Br2 (4) is orthorhombic, P212121, a 16.620(8), b 12.78(1), c 9.765(4) Ǻ, Z = 4 f.u ., R 0.073 for No 878. In (2)-(4), the cation configurations are similar, being of the form [L2Ca( dien )2], L (L') being the unidentate ligand, with the eight-coordinate calcium environments [L2Ca(N3)2] in a common isomeric configuration, the two ligands L being cis in an array of quasi-2 symmetry. Ca- Cl in (2) is 2.834(1) Ǻ; Ca-N generally range between 2.52(5) and 2.64(1) Ǻ; Ca-O(H2O) is 2.418(2) in (2), 2.434(7)-2.496(7) Ǻ in (3), while Ca-O( MeOH ) in (4) are 2.43(2) and 2.43(2) Ǻ. [Mg(HOMe)6] I2.2tmeda (5) ( tmeda = Me2N(CH2)2NMe2), orthorhombic, Pbca, a 23.423(8), b 15.306(4), c 9.345(1) Ǻ, Z = 4 f.u ., R 0.052 for No 1928, provides a usefully precise description for the centrosymmetric cation, Mg-O being 2.069(4), 2.080(4), 2.096(5) Ǻ, with Mg-O-C 128.4(4) l28.9(4), l29.7(4)°. [( tmeda )SrI2 ( HOMe )3].½tmeda (6), monoclinic, P 21/c, a 7.730(1), b 35.493(9), c 11.081(2) Ǻ, β 126.49(1)°, R 0.042 for No 3161, has a seven-coordinate, quasi-pentagonal bipyramidal SrN2I2O3 array about the metal with trans-iodines.

The subatomic resolution study of laccase inhibition by chloride and fluoride anions using single-crystal serial crystallography: insights into the enzymatic reaction mechanism

2019 ◽  
Vol 75 (9) ◽  
pp. 804-816 ◽  
Author(s):  
Konstantin M. Polyakov ◽  
Sergei Gavryushov ◽  
Tatiana V. Fedorova ◽  
Olga A. Glazunova ◽  
Alexander N. Popov
Keyword(s):  
Molecular Oxygen ◽  
Enzymatic Reaction ◽  
Copper Ion ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Fluoride Ions ◽  
X Ray ◽  
Mechanism Of Inhibition ◽  
Wide Range ◽  
Oxygen Ligand

Laccases are enzymes that catalyze the oxidation of a wide range of organic and inorganic substrates accompanied by the reduction of molecular oxygen to water. Here, a subatomic resolution X-ray crystallographic study of the mechanism of inhibition of the laccase from the basidiomycete fungus Steccherinum murashkinskyi by chloride and fluoride ions is presented. Three series of X-ray diffraction data sets were collected with increasing doses of absorbed X-ray radiation from a native S. murashkinskyi laccase crystal and from crystals of complexes of the laccase with chloride and fluoride ions. The data for the native laccase crystal confirmed the previously deduced enzymatic mechanism of molecular oxygen reduction. The structures of the complexes allowed the localization of chloride and fluoride ions in the channel near the T2 copper ion. These ions replace the oxygen ligand of the T2 copper ion in this channel and can play the role of this ligand in the enzymatic reaction. As follows from analysis of the structures from the increasing dose series, the inhibition of laccases by chloride and fluoride anions can be explained by the fact that the binding of these negatively charged ions at the position of the oxygen ligand of the T2 copper ion impedes the reduction of the T2 copper ion.

Low-coordinate yttrium in an oxygen ligand environment. Solid-state and solution characterization of hexakis(triphenylsiloxo)diyttrium

1991 ◽  
Vol 30 (18) ◽  
pp. 3570-3572 ◽  
Author(s):  
Paul S. Coan ◽  
Michael J. McGeary ◽  
Emil B. Lobkovsky ◽  
Kenneth G. Caulton
Keyword(s):  
Solid State ◽  
Ligand Environment ◽  
Oxygen Ligand
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