X-ray and high resolution selenium-77 solid state NMR spectroscopy as complementary probes to structural studies of organophosphorus diselenides

• Published in: Solid state nuclear magnetic resonance 1998-06, Vol.11 (3), p.215-224
• Main Authors: Potrzebowski, Marek J, Błaszczyk, Jarołsaw, Majzner, Wiesław R, Wieczorek, Michał W, Baraniak, Janina, Stec, Wojciech J
• Format: Article
• Language: English
• Subjects: Humans; Magnetic Resonance Spectroscopy - methods; NMR spectroscopy; Organophosphorus diselenide; Selenium - chemistry; Selenium-77
• ISSN: 0926-2040; 1527-3326
• DOI: 10.1016/S0926-2040(98)00030-7

77 Se high resolution solid state NMR spectroscopy was employed to study structural properties of bis(diisopropoxyphosphorothioyl) diselenide 1 and bis(dineopentoxyphosphorothioyl) diselenide 2. The principal elements T ii of 77 Se effective dipolar/chemical shift tensor were calculated from spinning sideband intensities employing the WIN-MAS program. The values of anisotropy and asymmetry parameters reflect the distortion of the selenium environment. It was found that the T 33 component mostly contributes to changes in the isotropic chemical shifts. 77 Se CP/MAS experiments were used to decide the assignment of space group by counting the number of crystallographically unique selenium centers in the unit cell. Crystals of diselenide 1 are triclinic, space group P1̄ with a=8.485(3) Å, b=8.508(1) Å, c=8.511(2) Å, α=98.835(15)°, β=111.653(24)°, γ=93.524(21)°, V=559.5(3) Å 3, D c=1.544(2) g/cm 3 and Z=1. Refinement using 2222 reflections for 157 variables gives R=0.037. Crystals of diselenide 2 are triclinic, space group P1 with a=9.1418(8) Å, b=9.1465(8) Å, c=9.9200(9) Å, α=74.751(8)°, β=74.629(7)°, γ=82.216(7)°, V=769.7(1) Å 3, D c=1.365(2) g/cm 3 and Z=1. Refinement using 3316 reflections for 297 variables gives R=0.0272.