Vanadium Part II. Benzohydroxamic Acid Complexes

Benzohydroxamic acid (RH₂) reacts with quadri- and quinque-valent vanadium to form compounds (I) [VO(BH)₂] and (II) [VO(OH)(RH)₂] in rose and violet-black colour respectively. Both these compounds dis­solve in boiling alcohols (methyl. ethyl and isopropyl) yielding red solutions from which silky brick-red crystals of composition, [VO(OX)(RH)₂] (III), have been characterised. Besides, violet-black complexes of the type M[VO(OH) (R)₂]{ where M=a bivalent cation such as Ba²⁺, [Cu[Big)₂]²⁺ or [Cu(Gau)₂]²⁺ } have also been prepared. Compound (I) is paramagnetic. whearas others are diamagnetic. Structural dispositions of the func­tional group of the ligand have also been related from the IR spectra of the potassium salt of the ligand and the complexes.