Crystal and molecular structure of 2-phenyl-2-thiono-5,6-(4′,5′-dimethylbenzo)-1,3,2-dithiaphosphepine and 2-methoxy-2-oxo-5,6-benzo-1,3,2-dioxaphosphepine

A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Branch, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 5, pp. 75–80, September–October, 1990.     

Three-dimensional structures of phosphorus-containing heterocycles. Communication 34. 2-Phenoxy-2-oxo-1,3,2-oxathiaphosphorinanes

Conclusions According to the data from the¹H NMR spectra, the dipole moments, and the Kerr effect, the preferred conformation of 2-aroxy-2-oxy-1,3,2-oxathiaphosphorinanes is a chair conformation with an axial orientation of the aroxy grouping and a gauche orientation of the aryl group relative to the P=O bond on the side of the cyclic oxygen atom. In the investigated compounds the p- conjugation is disrupted, as evidenced by the orthogonal orientation of the unshared pair of p electrons of the exocyclic oxygen atom and the orbitals of the benzene ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 570–575, March, 1985.     

Molecular structure of 4,5;7,8-(4′,4″-dimethyl-6′,6″-di-tert-butyl)dibenzo-6h-2-diethylamino-2-thiono-1,3,2-dioxaphosphocine

Conclusions X-ray structure analysis shows that for 4,5;7,8(4,4 -dimethyl-6,6-di-tert-butyl)-dibenzo-6H-2-diethylamino-2-thiono-1,3,2-dioxaphosphocine, the boat-chair conformation of C_s symmetry with an equatorial diethylamino group occurs in the crystal.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 74–77, January, 1989.     

Seven- and Eight-Membered Ring Conformations of Phosphorus Containing Heterocycles

Abstract

The conformational behaviour of seven- and eight-membered heterocycles based on their NMR spectrum and on a theoretical investigation is described. All possible basic conformations and their quantitative parameters have been considered. A molecular mechanics approach is applied to the calculation of the multidimensional maps of potential energy dependence on torsional angles.     

Three-dimensional structure of phosphorus-containing heterocycles

The dipole moments and molar Kerr constants of 2-chloro-5,5-dimethyl-2-chloro-, and 4-methyl-2-chloro-1,3,2-dioxaphosphorinanes were determined. It was found that a chair conformation with an equatorial p-Cl bond is realized in all cases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1324–1328, October, 1971.