Cooperative bimetallic catalysis has been documented in several recently reported asymmetric epoxide opening reactions that display second-order kinetic dependence on catalyst, specific requirements for multiple metal ions, and/or pronounced catalyst nonlinear effects.1 In such systems, one metal is proposed to serve as Lewis acid for epoxide activation and another as counterion for the nucleop...

Understanding an old dog’s tricks: The coupling of selective C–H activation with O2 by Co(salen).

From a combination of chiral Mn(salen) struts and the tetratopic ligand tetrakis(4-carboxyphenyl)benzene, a large-pore, noncatenated metal-organic framework (MOF) material, MnSO-MOF, has been synthesized. Following solvent exchange with hydrophobic CHCl(3), treatment of MnSO-MOF with aqueous H(2)O(2) allowed for the selective demetalation of Mn(salen) struts at and near the surface of the cryst...

In the title compound, [Ni(C(18)H(18)N(2)O(4))]·C(3)H(7)NO, the central Ni(II) atom is in a square-planar O(2)N(2) coordination environment. The planar Ni-salen moieties (r.m.s. deviation for the plane through the conjugated part of the Ni-salen group = 0.07 Å) form parallel stacks in the a-axis direction, with alternating Ni⋯Ni separations of 3.5339 (7) and 3.6165 (7) Å. In the crystal, there ...

Experimental work on the oxidation of the lignin model, syringyl alcohol, using oxygen and a Co(salen) catalyst has revealed variations in yield with different imidazole-based axial ligands. A reasonable linear relationship was found between product yield and pKa of the axial ligand. The current work, using density functional calculations, examined geometric, electronic, and energetic parameter...

Over the last six years, highly active catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide have been developed. Initial studies showed that bimetallic aluminium(salen) complexes [Al(salen)]2O formed active catalysts and kinetic studies allowed the catalytic cycle to be determined. The catalysts could be immobilized on silica, allowing them to be used in a gas phase...

Six transition metal-salen complexes (metal = Fe, Mn and Cr) 1-6 have been synthesized and characterized using different spectroscopic and electrochemical techniques. The binding studies of natural antioxidant, curcumin with the complexes (1-6) have been carried out by electronic absorption spectroscopic technique. The substantial shift in the absorption maximum of complexes (1-6) when they bin...