A redetermination of (2-methoxyphenyl)diphenylphosphine

The asymmetric unit of the title triphenylphosphine compound, C19H17OP, consists of two crystallographically independent molecules with similar conformations. One of these two molecules has a whole-molecule disorder over two positions with refined occupancies of 0.753 (3) and 0.247 (3). The dihedral angles between the three benzene rings are 89.69 (7), 76.54 (7) and 86.02 (7)° in the non-disordered molecule and the corresponding angles are 88.3 (4), 83.2 (4) and 84.2 (3)° for the major component and 80.2 (11), 89.5 (11) and 74.4 (9)° for the minor component of the disordered molecule. This structure has been reported previously [Suomalainen et al. (2000 ▶). Eur. J. Inorg. Chem. pp. 2607–2613]; however, the disorder detailed here was not mentioned in that determination. In the crystal structure, the molecules are stacked down the b axis and stabilized by C—H⋯π interactions.

The asymmetric unit of the title triphenylphosphine compound, C 19 H 17 OP, consists of two crystallographically independent molecules with similar conformations. One of these two molecules has a whole-molecule disorder over two positions with refined occupancies of 0.753 (3) and 0.247 (3). The dihedral angles between the three benzene rings are 89.69 (7), 76.54 (7) and 86.02 (7) in the non-disordered molecule and the corresponding angles are 88.3 (4), 83.2 (4) and 84.2 (3) for the major component and 80.2 (11), 89.5 (11) and 74.4 (9) for the minor component of the disordered molecule. This structure has been reported previously [Suomalainen et al. (2000). Eur. J. Inorg. Chem. pp. 2607-2613; however, the disorder detailed here was not mentioned in that determination. In the crystal structure, the molecules are stacked down the b axis and stabilized by C-HÁ Á Á interactions.

Related literature
For a previous report of this molecule, see: Suomalainen et al. (2000). For P-C bond lengths and C-P-C angles in related structures, see: Dunne & Orpen (1991); Shawkataly et al. (2009). For the stereochemistry of 2-methoxyphenyl diphenylphosphine complexes, see: Dahlenburg et al. (1997); Moreno et al. (2005). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 Table 1 Hydrogen-bond geometry (Å , ). Interestingly, the evidence of the disorder in this ligand has however been reported by Moreno et al., (2005) in a ruthenium complex.
This study was taken up as part of a project to study the stereochemistry of substituted triphenylphosphine ligands.
The asymmetric unit of (I), consists of two crystallographically independent molecules, A and B/C, with similar conformation ( Fig. 1, 2 & 3). Molecule B/C are the major/minor components of the whole-molecule disorder over two positions with refined occupancies of 0.753 (3) and 0.247 (3) respectively. The P-C bond lengths and C-P-C angles for the asymmetric unit are comparable to the related structures (Dunne & Orpen, 1991;Suomalainen et al., 2000;Shawkataly et al., 2009).
In the crystal structure, the molecules are stacked down the b axis ( Fig. 4) and stabilized by the C-H···π interactions (Table 1).

Experimental
The title compound was supplied by Strem Chemicals. Single crystals of (I) were obtained by slow evaporation of ethanol solution.

Refinement
All hydrogen atoms were positioned geometrically and refined using a riding model with C-H = 0.93-0.96 Å and U iso (H) = 1.2 or 1.5 U eq (C). A rotating-group model was applied for methyl groups. The same U ij parameters were used for atom pair C14B/C14C and all disordered atoms were subjected to rigid bond restraints (SAME and DELU). The C molecule is statistically disordered about the inversion center (3/4, 3/4, 0) with no actual close contacts (i.e. given a C molecule, the opposite molecule is a B molecule). Fig. 1. The molecular structure of the title compound with 30% probability ellipsoids for non-H atoms. Both disorder components are shown, with open bonds for the minor disorder component. Fig. 2. The molecular structure of the title compound with atoms label and 50% probability ellipsoids for non-H atoms. Only major disorder component is shown.  (2-methoxyphenyl)diphenylphosphine