(Methanol-κO)(methanolato-κO)oxido[N-(2-oxidobenzylidene)isoleucinato-κ3 O,N,O′]vanadium(V)

In the title complex, [V(C13H15NO3)O(CH3O)(CH3OH)], the VV atom is six-coordinated by a tridentate O,N,O′-donor ligand, derived from the condensation of salicylaldehyde and l-isoleucine, a vanadyl O atom, a methanolate O atom and a methanol O atom in a distorted octahedral geometry. The asymmetric unit contains two complex molecules. In the crystal, intermolecular O—H⋯O and C—H⋯O hydrogen bonds connect the molecules into a one-dimensional chain along [100].

In the title complex, [V(C 13 H 15

Experimental
Crystal data [V(C 13 H 15 NO 3

Data collection
Bruker SMART 1000 CCD diffractometer Absorption correction: multi-scan (SADABS;Sheldrick, 1996) Table 1 Hydrogen-bond geometry (Å , ).  The strong interest in vanadium compounds arises from the presence of vanadium in several metalloenzymes, their use as metallopharmaceutical agents and their catalytic abilities (Horn et al., 2004). Compared with other transition metal complexes, less vanadium complexes have been synthesized and characterized (Thompson et al., 1999;Wikksky et al., 2001). We report herein the synthesis and crystal structure of a new oxovanadium(V) complex with a tridentate Schiff base ligand derived from the condensation of salicylaldehyde and L-isoleucine.
As shown in Fig. 1, the asymmetric unit of the title compound contains two independent molecules. Each V V ion is six- complexes (Bian & Li, 2011;Cao et al., 2011;Chen et al., 2004). In the crystal, intermolecular O-H···O and C-H···O hydrogen bonds connect the molecules into a one-dimensional structure along [100] (Table 1, Fig. 2).

Experimental
L-Isoleucine (1 mmol, 131.2 mg) and potassium hydroxide (1 mmol, 56.1 mg) were dissolved in hot methanol (10 ml) with stirring and added successively to a methanol solution (5 ml) of salicylaldehyde (1 mmol, 0.11 ml). The mixture was then stirred at 333 K for 2 h. Subsequently, an aqueous solution (2 ml) of vanadyl sulfate hydrate (1 mmol, 225.4 mg) was added dropwise and stirred for 2 h continuously. Then the resultant solution was filtered and the filtrate was held at room temperature for several days, whereupon brown blocky crystals suitable for X-ray diffraction were obtained.

Figure 2
The one-dimensional structure of the title compound. Hydrogen bonds are shown as dashed lines.

(Methanol-κO)(methanolato-κO)oxido[N-(2-oxidobenzylidene)isoleucinato-κ 3 O,N,O′]vanadium(V)
Crystal data Orthorhombic, P2 1 2 1 2 1 Hall symbol: P 2ac 2ab a = 6.6148 (9) where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.007 Δρ max = 0.39 e Å −3 Δρ min = −0.41 e Å −3 Absolute structure: Flack (1983), 2690 Friedel pairs Flack parameter: 0.09 (5) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.