Polynuclear molybdenum(VI)–molybdenum(V) complex: a precursor of the catalyst for dinitrogen reduction

Abstract

Crystal structure was determined of the complex { [Mg2M08022(Me0)6(Me0H)4]z-[Mg(MeOH)6]2+}. 6MeOH ( l ) , isolated from methanolic solution containing Mov, MoVl, and Mgll compounds; when reduced to the Moll1 state the complex forms an active catalyst for N2 reduction in methanol at ambient temperature and pressure.

Controlled Synthesis and Chemical Conversions of FeO Nanoparticles

“…The octametallic core itself is closely related to the known edge‐sharing bioctahedral decametallate {M 10 O 28 } structure3 with removal of two metal ions from the shared edge. This has been observed previously for Mo in [Mg 2 Mo 8 O 22 (OMe) 6 (MeOH) 4 ] 2− 25. V5 and V5A have “slipped” away from the {V III 8 } core in 1 (V3 and V3A in 2 ) freeing two coordination sites to bridge further to other metal ions.…”

A Single‐Source‐Precursor Approach to Late Transition Metal Molybdate Materials: The Structural Role of Chelating Ligands in the Formation of Heterometallic Heteroleptic Alkoxide Complexes

“…It is the angle between the two Mo‐μ‐O bonds that distorts the octahedron the most; it is only 85.59(15)°. The Mo–O bonds for the two terminal methoxide groups [1.857(4) and 1.834(4) Å] are in agreement with the corresponding bonds in complexes such as [Mo(OMe) 6 ]28 and [Mo 2 O 2 (OMe) 8 ],29 and very close to those in [Mg 2 Mo 2 O 2 (OMe) 10 (MeOH) 4 ],30 a close structural analogue of 1 , where they vary between 1.862(4) and 1.909(4) Å. The two Mo–μ‐O bonds are longer [1.998(3) and 1.998(4) Å, respectively] and the Mo–μ 3 ‐O bond is even longer [2.187(3) Å] as this kind of bonding, with an atom shared with one or two other atoms, normally results in a significant increase of bond lengths.…”

Developing Pathways to the Synthesis of Low‐Valence Molybdenum Methoxides: Preparation, Characterization, and Redox Chemistry of Dimeric and Tetrameric Molybdenum Alkoxide Clusters

“…We performed cyclic voltammetry measurements in both protic (methanol) and aprotic (dmf) solvents. It is well established that a methanol media is essential for the functioning of Shilov's N 2 ‐fixing systems 9,39. Methanol apparently acts as the protonating agent but its role may, in fact, be dual because it is probable that reduction/oxidation of the active cluster in the course of a catalytic event may be accompanied by the protonation/deprotonation of ‐OR/ROH ligands, thus shifting the redox potential of the corresponding step.…”

“…However, methoxide clusters of low‐valence molybdenum (presumably, Mo 3+ ) represent a unique type of compound possessing unmatched catalytic activity in dinitrogen reduction under mild conditions9 (Mo clusters bearing alkoxide ligands other than OCH 3 were found to be inert towards N 2 activation). Unfortunately, the molecular and electronic structures of the catalytically active species are unknown and are the subjects of speculation based on the structures of the high‐valence precursors 10. It should also be noted that the chemistry of low‐valence molybdenum methoxides is represented just by a few scanty examples 11…”