Synthesis and crystal structures of dimeric schiff base oxovanadium(V) complexes with antimicrobial activity

Two new dimeric oxovanadium(V) complexes, VO₂L₁]₂ · 2H₂O (I) and VO₂L₂]₂ (II), where L¹ and L² are the monoanionic form of 5-methoxy-2-(2-methylaminoethylimino)methyl]phenol (HL¹) and 5-diethylamino-2-(2-methylaminoethylimino)methyl]phenol (HL²), respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination. The crystal of I is monoclinic: space group P2₁, a = 6.858(2), b = 16.630(3), c = 12.306(2) Å, β = 103.985(2)°, V = 1361.9(5) ų, Z = 2. The crystal of II is triclinic: space group $P\bar 1$ , a = 7.378(2), b = 8.838(2), c = 13.312(3) Å, α = 102.576(2)°, β = 92.044(2)°, γ = 113.017(2)°, V = 772.7(3) ų, Z = 2. The V...V distances are 3.140(1) Å in I and 3.254(1) Å in II. The V atoms in the complexes are in octahedral coordination. The effect of the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.