Metalloenzymes that carry a pterin-based molybdenum cofactor in their center catalyze numerous reactions in the human body and play a crucial role in its metabolism. Specifically, these enzymes promote redox reactions and oxygen transport in the body. Their absence may cause many problems leading to disability or even death in early childhood. Therefore, model compounds need to be synthesized and analyzed to investigate the reactivity, redox potential, and geometry of these cofactors. This study focused on electrode processes and determined the redox potentials of the new bis-(4-mercapto-5-(p-tolyl)-3H-1,2-dithiole-3-thione)-dioxomolybdenum complex by cyclic voltammetry. The 4-mercapto-5-(p-tolyl)-3H-1,2-dithiole-3-thione ligand underwent irreversible oxidation and reduction at thiol and thione functional groups. The new dioxomolybdenum complex showed a quasi-reversible two-stage electrode process.

No abstract

. This is a new synthetic method for preparing Mo-O-Mo bridged oxo(imido) molybdenum(V) species by double deprotonation of the anilines. The complexes were characterized by IR and 1 H-NMR. spectroscopy, FAB mass spectrometry, elemental analysis and X-ray crystallography which revealed that the two chloro ligands are trans to each other in 1b and 2, whereas they are cis to each other in 1a. All compounds have Mo-O-Mo linkages and near linear arylimido moieties.

The reaction between [MoTp∗(O)Cl2], [Tp* = hydrotris(3,5-dimetylpyrazol-1-yl)borate] and 4-bromoaniline in refluxing toluene gave geometric isomers of [MoTp*(O)Cl](μ-O)[MoTp*(Cl) (≡NC6H4Br)] (1a, cis; 1b, trans), but a similar reaction between [MoTp*(O)Cl2] and 4-chloroaniline yielded only one product, [MoTp*(O)Cl](μ-O)[MoTp∗(Cl)(≡NC6H4Cl)] (2) as a red crystalline solid. The new compounds were characterized by microanalytical data, mass, IR and 1H NMR spectroscopy. The X-ray structure analysis of 1a and 1b revealed that the complexes are geometric isomers, the two chloro ligands being cis in 1a and trans in 1b. Both compounds have Mo-O-Mo linkages and nearly linear arylimido moieties.