Crystal structures of a series of bis-(acetyl-aceto-nato)oxovanadium(IV) complexes containing N-donor pyridyl ligands.

Crystal structures for a series of bis-(acetyl-acetonato)oxovanadium(IV) complexes containing N-donor pyridyl ligands are reported, namely, bis-(acetyl-acetonato-κ2 O,O')oxido(pyridine-κN)vanadium(IV), [V(C5H7O2)2O(C5H5N)], 1, bis-(acetyl-acetonato-κ2 O,O')oxido(pyridine-4-carbo-nitrile-κN)vanadium(IV), [V(C5H7O2)2O(C6H4N2)], 2, and bis-(acetyl-acetonato-κ2 O,O')(4-meth-oxy-pyridine-κN)oxidovanadium(IV), [V(C5H7O2)2O(C6H7NO)], 3, Compounds 1-3 have the formulae VO(C5H7O2)2 L, where L = pyridine (1), 4-cyano-pyridine (2), and 4-meth-oxy-pyridine (3). Compound 1 was previously reported [Meicheng et al. (1984 ▸). Kexue Tongbao, 29, 759-764 and DaSilva, Spiazzi, Bortolotto & Burrow (2007). Acta Crystallogr., E63, m2422] and redetermined here at cryogenic temperatures. Compounds 1 and 2 as pyridine and 4-cyano-pyridine adducts, respectively, crystallize as distorted octa-hedral structures with the oxo and pyridyl ligands trans to one another. A crystallographic twofold axis runs through the O-V-N bonds. Compound 3 containing a 4-meth-oxy-pyridine ligand crystallizes as a distorted octa-hedral structure with the oxo and pyridyl ligands cis to one other, removing the twofold symmetry seen in the other complexes.