trans-Bis(1,3-diphenylpropane-1,3-dionato)(methanol)oxidovanadium(IV) methanol disolvate

In the title compound, [V(C15H11O2)2O(CH3OH)]·2CH3OH, the VIV atom is coordinated by two 1,3-diphenylpropane-1,3-dionate ligands and an oxide ligand in an axial position. The sixth position is occupied by the O atom of a methanol group bonded trans to the oxide atom. The octahedral geometry is significantly distorted, with the VIV atom lying 0.330 (3) Å above the equatorial plane formed by the O atoms of the two β-diketonate ligands. In the crystal, O—H⋯O hydrogen bonds between the coordinating methanol group in the complex and the two methanol solvent molecules lead to the formation of polymeric chains along the c-axis direction. Weak C—H⋯O contacts are also observed.

In the title compound, [V(C 15 H 11 O 2 ) 2 O(CH 3 OH)]Á2CH 3 OH, the V IV atom is coordinated by two 1,3-diphenylpropane-1,3dionate ligands and an oxide ligand in an axial position. The sixth position is occupied by the O atom of a methanol group bonded trans to the oxide atom. The octahedral geometry is significantly distorted, with the V IV atom lying 0.330 (3) Å above the equatorial plane formed by the O atoms of the two -diketonate ligands. In the crystal, O-HÁ Á ÁO hydrogen bonds between the coordinating methanol group in the complex and the two methanol solvent molecules lead to the formation of polymeric chains along the c-axis direction. Weak C-HÁ Á ÁO contacts are also observed.
Intermolecular O6-H6A···O7 hydrogen bonding in the order of 2.644 (2) Å was observed with a methanol solvent molecule. Additional intermolecular hydrogen bonding was also noted between O7-H7A···O8 i of the order 2.749 (2) Å and O8-H8A···O3 in the order of 2.853 (2) Å. These interactions eventually lead to the formation of polymeric chains of the complex along the c-axis, as illustrated in Figure 2.

Experimental
V 2 O 5 (1.0 g, 5.5 mmol) was added to a mixture of ethanol, water and sulfuric acid (5 cm 3 , 2 cm 3 and 2 cm 3 respectively) and refluxed for one hour, after which the yellow mixture turned a brilliant blue colour. A solution of 1,3-diphenylpropane-1,3-dione (4.93 g, 22 mmol) in ethanol (10 cm 3 ) was added to the reaction mixture which was then stirred for ca 10 min. A saturated solution of sodium carbonate in water (20 cm 3 ) was added to the mixture and the resulting green precipitate was collected by filtration. The precipitate was recrystallized from methanol and, after two weeks, small red needle-like crystals of [VO(dbm) 2 (MeOH)] were formed (yield: 2.35 g, 70%).

Refinement
The methyl and aromatic H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H = 0.95 and 0.98 Å and U iso (H) = 1.5Ueq(C) and 1.2Ueq(C), respectively. The hydrogen atoms of the methine groups, the methanol hydroxyl groups as well as the H atoms on C32 were located on the Fourier difference map and refined isotropically. The highest residual electron density was located 0.54 Å from H31C and the deepest hole was 0.68 Å from V1.

Figure 1
Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability displacement level.  Hydrogen bonds (indicated in blue) linking one of the compound molecules and a solvent molecule leads to the formation of polymeric chains of the compound along the c-axis. Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.