The synthesis, structure and spectroscopic properties of complexes with the formula [V I V O(dsal) 2 (H 2 O)], where Hdsal=salicylaldehyde, o-vanillin and 3-ethoxysalicylaldehyde, are presented. The crystal and molecular structures of [V I V O(o-van) 2 (H 2 O)] (1) (o-Hvan=o-vanillin=3-methoxysalicylaldehyde) is studied by single-crystal X-ray diffraction. Each molecule exhibits an octahedral geometry with the two o-van ligands coordinated cis to the V I V O 2 + group. 1 is the first example of a structurally characterized vanadium complex involving O a l d e h y d e as the donor atom and this enables a comparison between the bonding characteristics and the contributions of O a l d e h y d e , O a m i d e , O c a r b o x y l a t e and O k e t o n e (in acetylacetone) to the parallel hyperfine coupling constant in VOL 2 complexes.