Abstract
The reactions between [VO(acac)~2~] (acac^–^ = acetylacetonate ion) or [VO(OPr)~3~] and trianionic tetradentate N,N‐bis(2‐methylene‐4,6‐alkylphenolate)aminoethanolate ligands, [L1^3–^ (4,6‐dimethyl), L2^3–^ (4‐methyl, 6‐tert‐butyl), L3^3–^ (4‐tert‐butyl, 6‐methyl), L4^3–^ (4,6‐di‐tert‐butyl)], afford mononuclear complexes [VO(L1)] (1) and [VO(L2)] (2) with a trigonal bipyramidal coordination sphere around the V^V^ ion, or dinuclear octahedral complexes [V~2~O~2~(L3)~2~] (3) and [V~2~O~2~(L4)~2~] (4). In methanol an adduct with the formula [VO(L1)(MeOH)]·1/2MeOH (5) is obtained. According to multinuclear NMR spectroscopy all those complexes have a mononuclear structure in CDCl~3~ solutions. In wet polar solvents complex 1 reacts with water and N‐dealkylation occurs producing 3,5‐dimethylsalicyl alcohol, which condensates with 1 and forms a new oxidovanadium complex 6. An ether bond links 3,5‐dimethylsalicyl alcohol to the L1^3–^ ligand. To support the reaction mechanism, we have found that in dry acetonitrile 1 reacts directly with salicyl alcohol forming compound 7, which is similar to 6. All compounds 1–7 have been characterized by elemental analysis, multinuclear NMR and X‐ray diffraction.