2-[3-(Trifluoromethyl)phenoxy]ethyl 1-oxo-2,6,7-trioxa-1λ5-phosphabicyclo[2.2.2]octane-4-carboxylate

In the crystal structure of the title compound, C14H14F3O7P, the central chain, which connects the phosphate bicyclic system and the benzene ring, is made up of an approximately planar C—C(O)—O—C(H2) fragment and a C(H2)—O—C(Ph) link; the mean planes make a dihedral angle of 75.9 (2)°. The F atoms are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.


S1. Comment
Heterocyclic derivatives containing bicyclic phosphate system are important compounds with versatile industrial and biological applications (Ratz, 1966;Li et al., 2002). In continuation of our work on new biologically active heterocyclic derivatives, we report here the crystal structure of the title compound,(I) (Fig.1).Bond lengths and angles of the phosphorus-containing bicyclic cage of (I) are close to those observed previously in similar compounds (Nimrod et al., 1968;Sheng & He, 2006). The central chain of the molecule, which connects phosphate bicyclic system and benzene ring, is made up of approximately planar C4-C5-O6-C6 fragment and C7-O7-C8 link; their mean planes form dihedral angle of 75.9 (2)°.

S3. Refinement
It was apparent at an early stage, that the CF 3 group showed rotational disorder, and two alternative positions were revealed for each of the F atoms. Refinement of the s.o.f.'s for the F atoms indicated noticeable differences in occupancies of each of the two orientations of the CF 3 group [0.59 (2) versus. 0.41 (2)]. The C-F bond distances were restrained during the refinement using the SADI command (SHELXL97; Sheldrick, 2008). H atoms were included in the refinement in riding model approximation with C-H = 0.93 Å for aromatic and 0.97 Å for all other H atoms; U iso (H) = 1.2U eq of the carrier C atom.  The structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme; the minor component of the CF 3 group disorder is omitted. H atoms are shown as small spheres of arbitrary radius.

Figure 2
Packing diagram for (I).

Figure 3
The formation of the title compound, (I). where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.27 e Å −3 Δρ min = −0.22 e Å −3 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.

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