Synthesis and crystal structures of the dioxovanadium complexes [VO2L1] and [VO2L2]2

Two new oxovanadium complexes, [VO₂L¹] (I) and [VO₂L²]₂ (II), where L¹ and L² are the deprotonated forms of 4-bromo-2-[(2-diethylaminoethylimino)methyl]phenol (HL¹) and 4-bromo-2-{[2-(2-hydroxyethylamino)ethylimino]methyl}phenol (HL²), respectively, have been synthesized and characterized by IR spectra and single crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/n, a = 14.300(3), b = 7.010(2), c = 15.460(2) ?, ?? = 107.401(2)°, V = 1478.7(5) ?³, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 7.270(2), b = 15.373(3), c = 11.893(3) ?, ?? = 99.302(2)°, V = 1311.8(5) ?³, Z = 2. Complex I is a mononuclear dioxovanadium(IV) complex. Complex II is a centrosymmetric dinuclear dioxovanadium(V) complex with a V...V distance of 3.117(2) ?. The Vatom in I is in a distorted square-pyramidal coordination, and that in II is in an octahedral coordination. The difference in the structures of the complexes is largely induced by the hydrogen bonds during the self-assembly process.