Bis(1-ferrocenylethanone oximato)triphenylantimony(V)

In the title compound, [Fe2Sb(C5H5)2(C6H5)3(C7H7NO)2] or [Sb(C6H5)3{Fe(C5H5)(C7H7NO)}2], the Sb center has a slightly distorted trigonal-bipyramidal geometry, with the three phenyl ligands in equatorial positions and the two O atoms from the ferrocenylethanone oximate ligands in axial positions. The crystal structure is stabilized by two intermolecular C—H⋯π interactions.

In the title compound, [Fe 2 Sb(C 5 H 5 ) 2 (C 6 H 5 ) 3 (C 7 H 7 NO) 2 ] or [Sb(C 6 H 5 ) 3 {Fe(C 5 H 5 )(C 7 H 7 NO)} 2 ], the Sb center has a slightly distorted trigonal-bipyramidal geometry, with the three phenyl ligands in equatorial positions and the two O atoms from the ferrocenylethanone oximate ligands in axial positions. The crystal structure is stabilized by two intermolecular C-HÁ Á Á interactions.

Related literature
For antimony compounds with cytotoxicity and antitumor activities, see: Takahashi et al. (2002). For a related structure, see: Sharma et al. (2003).

S1. Comment
Research on some main group and early transition metal complexes with internally functionalized oximes have shown that oximes were an important class of N/O donor ligands having different coordinating abilities with the metal centers (Sharma, et al., 2003). On the other hand, antimony compounds have been reported with good cytotoxicity and antitumor activities, some of them can affect the repair of the DNA-double strand break (Takahashi et al., 2002). However, to our best knowledge, corresponding triorganoantimony (V) compounds with these ligands were hitherto unknown. Here we report the crystal structure of the title compound, bis(acetylferrocenyoximato)triphenylantimony(V) (Fig. 1).
The compound was an interesting heterometallic (Sb, Fe) compound (Fig.1). The Sb atom is five-coordinated with a distorted trigonal-bipyramidal geometry (Table 1 [119.6 (4)°] bond angles is 360°, which shows that these atoms have slightly deviations from ideal trigonal-bipyramidal geometry. The crystal structure is stabilized by two intermolecular C-H···π interactions (Table 1 and Fig. 2); one between a cyclopentadienyl-H atom and the cyclopentadienyl ring of a neighbouring molecule, with a C11-H11···Cg1 i separation of 2.78 Å, a second between a cyclopentadienyl H atom and the benzene ring of an adjacent molecule, with a C21-H21···Cg2 ii separation of 3.03 Å (Cg1 and Cg2 are the centroids of the C15-C19 cyclopentadienyl ring and the C25-C30 benzene ring, respectively, symmetry code as in Fig. 2).

S2. Experimental
Acetylferrocenyloxime (1.46 g, 6 mmol) was added to a stirring solution containing dibromotriphenylantimony (1.54 g, 3 mmol) in tetrahydrofuran (50 ml). After stirring for 12 h at room temperature the orange solution was obtained and then  The molecular structure of (I) with displacement ellipsoids for non-hydrogen atoms drawn at the 30% probability level.

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.