VanadylIV

Vanadyl(IV) refers to the vanadium(IV) oxido cation, commonly described as the vanadyl ion VO2+. The term vanadyl highlights the characteristic short V=O bond that is present in this oxidation state and in many oxido-vanadium complexes. In coordination compounds, VO2+ is typically five- or six-coordinate, with one strong axial V=O bond and additional ligands in the equatorial plane, leading to a distorted octahedral or square-pyramidal geometry.

Electronic and magnetic properties arise from vanadium in the d1 configuration. VO2+ species are paramagnetic and exhibit characteristic electronic spectra and, in many cases, a distinctive electron-paramagnetic-resonance (EPR) signal due to the unpaired electron. Complexes of vanadyl(IV) often feature ample ligand flexibility, including oxygen- and nitrogen-donor ligands such as sulfates, carboxylates, polyaminocarboxylates, and Schiff bases.

Occurrence and preparation are typically through vanadium(IV) salts, such as vanadyl sulfate or related oxido derivatives, and VO2+ motifs are common in solution and solid-state complexes. They also serve as useful precursors to broader vanadium-oxide chemistry and to VO2-containing materials.

Applications and significance include use as catalysts in oxidation reactions (for example, alkane or sulfide oxidations) and as precursors to vanadium oxide catalysts and materials for energy storage. VO2+-based complexes are investigated for fundamental coordination chemistry and for their role in designing selective oxidation catalysts.

Safety considerations: vanadium(IV) compounds can be toxic and should be handled with appropriate precautions, including avoidance of inhalation and ingestion and proper waste disposal.