{4-Hydroxy-N′-[(2E,3Z)-4-oxido-4-phenylbut-3-en-2-ylidene]benzohydrazidato}diphenyltin(IV) methanol monosolvate

Two independent diphenyltin molecules and two independent methanol molecules comprise the asymmetric unit of the title compound, [Sn(C6H5)2(C17H14N2O3)]·CH3OH. The Sn atom in each is five-coordinated by a tridentate ligand and the ipso-C atoms of the Sn-bound benzene substituents. The resulting C2N2O donor set defines a coordination geometry that is intermediate between trigonal-bipyramidal (TP) and square-pyramidal (SP), with one molecule slightly tending towards TP and the other slightly towards SP. The molecules differ in terms of the relative orientations of the terminal benzene rings [dihedral angles = 45.71 (18) and 53.98 (17)°] and of the Sn-bound benzene substituents [dihedral angles = 59.5 (2) and 45.77 (18)°, respectively]. The most prominent feature of the crystal packing is the formation of four-molecule aggregates via O—H⋯O and O—H⋯N hydrogen bonds, in which the hydroxy group is connected to a methanol molecule which, in turn, is linked to a non-coordinating N atom. Weak C—H⋯π interactions also occur.

Two independent diphenyltin molecules and two independent methanol molecules comprise the asymmetric unit of the title compound, [Sn(C 6 H 5 ) 2 (C 17 H 14 N 2 O 3 )]ÁCH 3 OH. The Sn atom in each is five-coordinated by a tridentate ligand and the ipso-C atoms of the Sn-bound benzene substituents. The resulting C 2 N 2 O donor set defines a coordination geometry that is intermediate between trigonal-bipyramidal (TP) and squarepyramidal (SP), with one molecule slightly tending towards TP and the other slightly towards SP. The molecules differ in terms of the relative orientations of the terminal benzene rings [dihedral angles = 45.71 (18) and 53.98 (17) ] and of the Snbound benzene substituents [dihedral angles = 59.5 (2) and 45.77 (18) , respectively]. The most prominent feature of the crystal packing is the formation of four-molecule aggregates via O-HÁ Á ÁO and O-HÁ Á ÁN hydrogen bonds, in which the hydroxy group is connected to a methanol molecule which, in turn, is linked to a non-coordinating N atom. Weak C-HÁ Á Á interactions also occur.

Related literature
For background to the biological interest in related compounds, see: Affan et al. (2010). For related structures, see: Affan et al. (2009Affan et al. ( , 2011. For additional structural analysis, see: Addison et al. (1984).
1. The resulting C 2 NO 2 donor set defines a coordination geometry intermediate between square pyramidal and trigonal bipyramidal geometry. This is quantified by the value of τ = 0.55 [Sn1] which compares to the τ values of 0.0 and 1.0 for ideal square pyramidal and trigonal bipyramidal geometries, respectively (Addison et al., 1984). The value for the Sn2 atom, τ = 0.47, indicates a small deviation towards square pyramidal. The τ value for the dimethyl derivative of 0.51 (Affan et al.,

2011) is intermediate between those calculated for the molecules in (I).
The five-membered SnCN 2 O chelate ring is buckled with a r.m.s. deviation = 0.182 Å and with maximum deviations of 0.116 (1) and -0.144 (2) Å for the Sn1 and N2 atoms, respectively [the equivalent parameters for the second molecule are r.m.s. = 0.224 Å, max. deviations: 0.142 (1) for Sn2 and -0.176 (3) for N4]. There is also considerable distortion in the SnC 3 NO six-membered chelate with the r.m.s. deviation being 0.185 Å, and with the O3 and Sn1 atoms lying 0.214 (2) and -0.160 (1) Å out of the least-squares plane [the equivalent parameters for the second molecule are r.m.s. = 0.222 Å, max. deviations: 0.255 (2) for O6 and -0.191 (1) for Sn2]. The hydroxybenzene ring is slightly twisted out of the plane from the adjacent five-membered chelate ring as seen in the O1-C1-C2-C3 torsion angle of -4.8 (5) ° [an even greater twist is found for the second molecule with O4-C30-C31-C32 being -170.3 (3) °]. By contrast, significant twists are found between the benzene ring and six-membered chelate ring with the O3-C11-C12-C13 torsion angle being -159.6 (3) ° [again, an even greater twist is found for the second independent molecule with O6-C40-C41-C42 = 150.4 (3)°] . The dihedral angle between the terminal benzene rings is 45.71 (18) ° consistent with twist in the tridentate ligand [the equivalent value for the second molecule is 53.98 (17) °]. The aforementioned differences are highlighted in the overlay diagram shown in Fig. 3. The other notable difference between the two independent molecules is found in the dihedral angle formed between the tin-bound benzene rings, i.e. 59.5 (2) ° for the Sn1-molecule and 45.77 (18) ° for the Sn2-molecule.
The crystal structure features four molecule aggregates whereby centrosymmetrically related molecules are bridged by methanol molecules. The connections between the molecules are O-H···O hydrogen bonds formed between the benzenehydroxy group and the methanol-O, and O-H···N hydrogen bonds formed between the methanol and the non-coordinating nitrogen atom, Table 2. The resultant aggregate is cyclic and is stabilized by a 20-membered {···HO···HOC 5 N} 2 synthon as illustrated for the Sn1 molecule in Fig. 4. Globally, the crystal structure comprises alternating layers made up of Sn1 and Sn2 molecules that stack along the a direction and are connected by C-H···π interactions, Table 2. supplementary materials sup-2 Experimental Benzoylacetone 4-hydroxybenzhydrazone (0.59 g, 2 mmol) was dissolved in distilled methanol (20 ml) under a nitrogen atmosphere. Potassium hydroxide (0.23 g, 4 mmol) dissolved in methanol (10 ml) was added drop wise to the solution during which the colour of the solution changed from yellow to orange. The resulting mixture was refluxed for 1 h, then treated with diphenyltin dichloride (0.687 g, 2 mmol) in methanol (10 ml), heated under reflux for 4 h and allowed to cool to room temperature. Potassium chloride that formed during the reaction was removed via filtration. The filtrate was evaporated to dryness using a rotary evaporator to obtain yellow microcrystals. The microcrystals were filtered off, washed with ethanol and dried in vacuo over P 2 O 5 overnight. Yellow blocks of (I) were obtained by slow evaporation of methanol and diethyl

Refinement
Carbon-bound H-atoms were placed in calculated positions (O-H = 0.84 Å; C-H = 0.95 to 0.98 Å) and were included in the refinement in the riding model approximation with U iso (H) set to 1.2-U eq (C) and 1.5-U eq (O, methyl-C). Fig. 1. The molecular structure of the first independent molecule of (I) showing displacement ellipsoids at the 50% probability level.