2-(4-Methoxyphenyl)-4H-1,3,2-benzoxathiaphosphinine 2-sulfide

The asymmetric unit of the title compound, C14H13O2PS2, contains two crystallographically independent molecules, which differ in the conformation of the 1,3,2-benzoxathiaphosphinine moieties (screw boat in the first molecule and envelope in the second molecule). In the crystal, neither classical nor non-classical hydrogen bonds are found. Weak interactions (about 2.9–3.0 Å) between the lone pair of the terminal S atoms with H atoms occur. This compound was further characterized by 1H NMR and IR spectroscopy.

The asymmetric unit of the title compound, C 14 H 13 O 2 PS 2 , contains two crystallographically independent molecules, which differ in the conformation of the 1,3,2-benzoxathiaphosphinine moieties (screw boat in the first molecule and envelope in the second molecule). In the crystal, neither classical nor non-classical hydrogen bonds are found. Weak interactions (about 2.9-3.0 Å ) between the lone pair of the terminal S atoms with H atoms occur. This compound was further characterized by 1 H NMR and IR spectroscopy.
The asymmetric unit of a crystal of I contains two crystallographically independent molecules, which are different by the conformation of the 1,3,2-benzoxathiaphosphinine moieties: in molecule a -screw boat, and in molecule b -distorted envelope. The Zotov-Palyulin puckering parameters for molecule a are: S = 0.886, θ = 80.83°, ψ 2 = 347.94°, σ = 4.21 (Zefirov et al., 1990;Zotov et al., 1997)   Single crystals for X-ray analysis were obtained by slow evaporation of a methanol solution. IR-spectrum was recorded (in KBr) on Shimadzu FTIR-8400S. Mass-spectrum was measured on Finnigan Trance DSQ spectrometer. 1 H NMR spectrum was obtained in DMSO-d 6 on Jeol JNM-ECX400 (400 MHz), using TMS as internal standard. Elemental composition was determined on Euro Vector EA-3000 elemental analyzer.

Refinement
C-bound H-atoms were placed in calculated positions with C-H 0.95 Å for aromatic, 0.99 Å for methylene with U iso (H) = 1.2U eq (C) and 0.98 Å for methyl with U iso (H) = 1.5U eq (C). All H atoms refined as riding.
Technical problems during the diffraction experiment led to the loss of 87 reflections.  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 > 2σ(F 2 ) is used only for calculating Rfactors(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