The Chemistry of Transition Metal Complexes Containing Catechol and Semiquinone Ligands

In order to study the reactivity pattern of Mo−Ot bonds associated with anionic sulfur ligands, precursor complexes MoO2L·D (H2L = S-methyl 3-(2-hydroxyphenyl)methylenedithiocarbazate; D = CH3OH (1), H2O (2)) were synthesized. Complex 2 crystallizes in the orthorhombic space group P212121, with a = 6.079(1) A, b = 11.638(2) A, c = 17.325(2) A, V = 1225.7(4) A3, and Z = 4. In its reaction with PhNHOH, 1 forms a seven-coordinate oxaziridine compound [MoO(η2-ONPh)L·CH3OH] (3) by oxo-rearrangement (elimination−substitution) without a change in the molybdenum oxidation state. The crystal data for 3 are a = 9.573(3) A, b = 9.859(2) A, c = 10.604(3) A, α = 95.90(2)°, β = 95.81(2)°, γ = 112.12(2)°, V = 911.5(4) A3, Z = 2, and triclinic space group P1. In contrast to that of the precursor compound 1 (Mo−Ot = 1.700(4) A), the terminal Mo−Ot distance in 3 (1.668(2) A) is typical of Mo−O bonds of order 3, which drives the formation of an apparently unstable three-membered metallacycle via spectator oxo stabilization...

Reactivity of Mo−Ot Terminal Bonds toward Substrates Having Simultaneous Proton- and Electron-Donor Properties: A Rudimentary Functional Model for Oxotransferase Molybdenum Enzymes§

Ministerio de Ciencia e Innovacion (MICINN) and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) and Junta de Castilla y Leon (BU021 A09 and GR-172) for financial support. P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contracts

Pinacol as a New Green Reducing Agent: Molybdenum‐ Catalyzed Chemoselective Reduction of Sulfoxides and Nitroaromatics

This microreview gives an overview about advances in bioinorganic model chemistry for molybdenum- and tungsten-dependent oxidoreductases with respect to specific aspects of the evolution, structure or function of distinct active-site properties. The approaches to evaluate catalytic properties fine-tuned by the ligand sphere, interpret and assign enzyme spectra and to understand why two different metals are used for the same task but in distinct habitats and respective evolutionary aspects are discussed on the basis of exemplary case studies. This short review provides a personal perspective and appreciation of the complex problems associated with the respective foremost synthetic and analytical model chemistry and their solutions partly accompanied and supported by theoretical results.

Molybdenum and Tungsten Oxidoreductase Models

Synthesis, spectral and electrochemical studies of arylazopyridine complexes of palladium(ii) with dioxolenes

Synthesis of (1,2-benzenediolato(2-)-0,0')oxobis(1-piperidinolato(1-)-0,n)molybdenum( vi), [moo(c5h10no)2(c6h4o2)], and structure determination by correlated h-1-c-13 two-dimensional nmr-spectroscopy and x-ray crystallography

Jh Enemark

Papers

Synthesis of (1,2-benzenediolato(2-)-0,0')oxobis(1-piperidinolato(1-)-0,n)molybdenum( vi), [moo(c5h10no)2(c6h4o2)], and structure determination by correlated h-1-c-13 two-dimensional nmr-spectroscopy and x-ray crystallography