Steric control of vanadium(V) coordination geometry: a mononuclear structural model for transition-state-analog RNase inhibitors

Abstract

The role played by vanadium in biochemistry has become widely appreciated in recent years.1-3 Its involvement ranges from being the active-site metal in a number of enzymes (bromoperoxidase and nitrogenase) to being a potent inhibitor of others.4-7 Among this latter group are the phosphate-metabolizing enzymes such as RNase, where bound vanadate has been proposed to function as a transition state analog of the pentavalent trigonal bipyramidal intermediate of phosphate hydrolysis.8 This supposition, first presented by Lindquist et al., was based on the known coordination

N,N′‐Ethylenebis(pyridoxylideneiminato) and N,N′‐Ethylenebis(pyridoxylaminato): Synthesis, Characterization, Potentiometric, Spectroscopic, and DFT Studies of Their Vanadium(IV) and Vanadium(V) Complexes

“…The VÀV separation is 3.166(1) ä, comparable to the values found in related complexes that range from 3.103 ä to 3.372 ä. [30,31,33,34] Owing to the presence of two crystallization water molecules, there is an extended hydrogen-bonding network in the three-dimensional crystal structure, which involves both the bridging m-oxygen atom O2, the hydroxyl O5 atom, and the pyridine N3 atom (see Supporting Information).…”

Effect of the chloro-substitution on lowering diabetic hyperglycemia of vanadium complexes with their permeability and cytotoxicity

“…The apical position is occupied by a second oxo ligand O1. The V1eO1 and V1eO2 distances of 1.608(2) and 1.6801 (19) Å are somewhat longer than the value of 1.585 (7) Å reported for VO (salen) [31,32] complexes but compare well with the values of 1.605 (2) and 1.647 (2) Å reported by Plass [33] and Ligtenbarg [34] for dioxovanadium complexes. The average VeO bond length and OeVeO angle are similar to those reported previously for the cis-VO 2 moiety in other complexes [35].…”

Synthesis, characterization and urease inhibitory activity of oxovanadium(V) complexes with similar Schiff bases

“…The coordination geometry around the metal center in each of the complexes can be best described as a distorted square pyramid, The bond distances between the V atoms and the oxo O atoms indicate that they are typical double bonds. The corresponding bond distances and bond angles in the complexes are very close to each other, and also comparable to those observed in other oxovanadium (V) complexes with Schiff bases [25][26][27].…”