Experimental and theoretical study of a truly functional biomimetic molybdenum oxotransferase analogue system

Bioinspired functional analogs of the active site of molybdenum enzymes: Intermediates and mechanisms

“…4a. In the resulting phosphoryl molybdenum(IV) complex the Mo O bond length of the spectator oxygen is shortened as calculated by DFT [96] in accordance with the expected "spectator oxygen effect" (Fig. 4b) [20,21].…”

Oxidomolybdenum(IV), ‐(V), ‐(VI) Complexes with Relevance to Molybdenum Enzymes: Oxygen Atom Transfer, Redox Chemistry and EPR Spectroscopy

“…[39] These absorptions are found at lower energy than those of the corresponding neutral molybdenum(VI) complex 1 featuring ν = 930, 902 cm -1 . [16] DFT calculations of models of 1 and 1 - [19] predict a shift (scaled by 0.9614 [40] ) from ν = 940, 914 cm [41] The EPR signal of the Mo V state of formate dehydrogenase is also reported to be split by proton coupling with A iso ( 1 H) = 16 G. [42] The anisotropic EPR spectra of frozen solutions of 1 -, 7 and 8 are shown in Figures 7, 8, and 9. All observed g values are Ͻ 2.0, and hyperfine coupling to 95/97 Mo isotopes is also detected.…”

“…Thus, the data obtained in the homogeneous system suggest that the Mo IV -to-Mo V oxidation precedes water/hydroxide coordination. [16,19] One-Electron Reduction of 1 (Mo VI Ǟ Mo V )…”

“…Theoretical studies have been invoked to further substantiate the mechanistic description of the catalytic cycle. [19] Here, we describe detailed investigations of homogeneous OAT and CEPT reactions with relevance to the biomimetic catalytic cycle of the heterogeneous system starting from the previously prepared and characterized cis-dioxidomolybdenum(VI) complex 1 (Scheme 2). [16,19] We study the OAT of 1 to substrates of different size and basicity and describe our attempts to generate and observe EPR-active molybdenum(V) intermediates generated by CEPT in homogeneous solution, which are potentially relevant for the catalytic cycle.…”

Proton and Electron Transfer to a Polymer‐Supported Nitrido Molybdenum(VI) Complex

“…Furthermore, relevant intermediates in the oxidation states IV, V, and VI have been characterized. [27][28][29][30] We report here our attempts to immobilize nitrido molybdenum(VI) complexes relevant to the second half of the Schrock-Yandulov cycle onto a solid polymer support. In addition, we describe their reactivity towards protons and electrons.…”