Bis(2-{[(9H-fluoren-2-yl)methylidene]amino}phenolato-κ2 N,O)zinc methanol disolvate

In the title compound, [Zn(C20H14NO)2]·2CH3OH, the ZnII atom lies on a crystallographic twofold rotation axis and is coordinated by two O atoms and two N atoms from two bidentate 2-{[(9H-fluoren-2-yl)methylidene]amino}phenolate ligands within a distorted tetrahedral geometry. The dihedral angle between the two chelate rings is 82.92 (5)°. In the coordinated ligand, the phenol ring is twisted at 30.22 (9)° from the mean plane of the fluorene ring. In the crystal, O—H⋯O hydrogen bonds link the complex molecules to the methanol solvent molecules.

In the title compound, [Zn(C 20 H 14 NO) 2 ]Á2CH 3 OH, the Zn II atom lies on a crystallographic twofold rotation axis and is coordinated by two O atoms and two N atoms from two bidentate 2-{[(9H-fluoren-2-yl)methylidene]amino}phenolate ligands within a distorted tetrahedral geometry. The dihedral angle between the two chelate rings is 82.92 (5) . In the coordinated ligand, the phenol ring is twisted at 30.22 (9) from the mean plane of the fluorene ring. In the crystal, O-HÁ Á ÁO hydrogen bonds link the complex molecules to the methanol solvent molecules.

Experimental
Crystal data [Zn(C 20 Table 1 Selected geometric parameters (Å , ).   Schiff base ligands have attracted attention due to their facile syntheses, easily tunable steric and electronic properties resulting in a good performance in sensor technologies and electroluminescence devices (Ji et al., 2012;Niu et al., 2012;Liu et al., 2011;Roy et al., 2009). Recently, we reported group 12, Hg(II) complexes with Schiff bases with an emphasis on their luminescent properties (Kim & Kang, 2010;Kim et al., 2011). Herein, we designed new Schiff base containing a fluorene moiety since flourene has high triplet energy and good-hole transporting ability (Scaria et al., 2010;Loy et al., 2002;Miteva et al., 2001) and synthesized its Zn(II) complex. The title compound shows a red emission at 611 nm with a quantum yield of 1.2% in a DMF solution upon 300 nm excitation.
Preparation of zinc(II) compound: the reaction of L compound (1.50 g, 10 mmol) with zinc(II) acetate (0.91 g, 5 mmol) in methanol/methylenechloride (1:1 v/v) (40 ml) at 50 °C for 5 h yielded the title compound as an orange powder. The powder was filtered off and washed with hexane. Yield: 0.95 g (30%). Orange crystals of (I) were obtained from its ethanol solution by slow evaporation of the solvent at room temperature.

Refinement
Atom H24 of the OH group was located from a difference Fourier map and refined freely [refined distance; O-H = 0.98 (4) Å]. Other H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 -0.97 Å with U iso (H) = 1.2U eq (carrier C) for aromatic-and methylene-H, and 1.5U eq (carrier C) for methyl-H atoms. program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).  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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq