Graphical Abstract: Two vanadium(V) complexes comprising VO3+ and VO2+ cores with o-vanillin semicarbazone (H2L) have been synthesized and characterized by IR, NMR spectroscopies and single-crystal X-ray diffraction study. The coordination polyhedra are a O5N distorted octahedron in the mono-oxidovanadium complex [VO(HL)(EtO)(EtOH)0.6(H2O)0.4][VO(HL)(SO4)(EtO)]•0.4EtOH (1) and a O4N square-pyramid in the dioxidovanadium compound [VO2(HL)]•2H2O (2).