Conformational and solid-state studies of diphenyl 1-hydroxy-1-phenylethylphosphonate

Abstract

The crystal structure of the title compound, diphenyl 1‐hydroxy‐1‐phenylethylphosphonate (1), was determined by the single‐crystal X‐ray diffraction method. The crystallographic data for 1 are as follow: C20H19O4P, Mr = 354.34, monoclinic, P21/n, a = 9.787(1) Å, b = 20.235(1) Å, c = 9.797(1) Å, β = 106.18(3)°, V = 1863.3(4) Å3, Z = 4, Dcalc = 1.26 g/cm3, λ(Mo‐Ka) = 0.71073 Å, μ = 1.6 cm−1, F(000) = 744, R = 0.018, and Rw = 0.032 for 2258 observed reflections. The solid‐state structure in a dimeric packing mode exhibits intermolecular hydrogen bonding of the type P = O···H–O. Infrared solution studies (CCl4) indicate that upon high dilution (10−4 M) the dimers completely dissociate to give conformers with and without intramolecular hydrogen bonds. Theoretical studies (PM3) were undertaken to determine the energy profile about the P–C torsional angle, which exhibited low energy barriers to rotation with no clear minimum energy conformation. © 1996 John Wiley & Sons, Inc.

Diphenyl (hydroxyphenylmethyl)phosphonate

“…They are useful reagents for the synthesis of enol ethers andketophosphonates (Babak & Rahman, 2001). Bond lengths and angles in the title compound, (I), are in agreement with the values reported in the literature (Lane et al, 1996;Fang et al, 2006). The hydroxy group is involved in hydrogen-bonding interactions with the phosphoryl O atom of a neighboring molecule [OÁ Á ÁO = 2.691 (2) Å ] (Table 1 and Fig.…”