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

TLDR: 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 as discussed by the authors.

Abstract: 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...