Protonated amino alcohols as cations in synthesis of vanadium(V) complexes with Schiff base ligands as potential insulin-mimetic agents

•Dioxidovanadium(V) complexes with Schiff base ligands and amino alcohols as cations were studied.•The ionic complexes are very well soluble in water in contrast to their neutral analogues.•The X-ray structure analysis especially with hydrogen bonding description was described.•The complexes are stable at pH = 7 and show better stability at pH = 2 in contrast to neutral vanadium complexes. Series of ionic dioxidovanadium(V) complexes with Schiff base ligands based on 2-hydroxybenzhydrazide and substituted salicylaldehydes were synthesized and described. As cations, the organic compounds like 2-aminoethanol (AMET) and 3-amino-1-propanol (AMPR) were used. The complexes of general formula HAMET[VO2L] and HAMPR[VO2L] (where L = ONO-donor Schiff base ligand) were characterized by X-ray single crystal structure measurements as well as elemental analysis, IR and UV–Vis spectroscopy. The complexes were very well soluble in water in contrast to their neutral analogues, what gives the opportunity to measure their stability in this solvent. The stability was also tested at pH = 2 by UV–Vis spectra measurement. The results were compared to neutral vanadium complexes with Schiff base ligands, previously studied as potential insulin-mimetic agents. [Display omitted]