Electric and Magnetic Anisotropy in Structural Organophosphorus Chemistry

Abstract

The principles of study of the electric polarizability and magnetic susceptibility anisotropy of phosphorus derivatives have been discussed. The molar constants of birefringence in the transverse magnetic field (Cotton-frlouton constants, lo¹⁸ e.m.u.) have been determined for 2-methoxy-4-methyl-1,3,2-dioxaphosphorinane (-1.31, its 2-oxoanalogue (1.5), 2-thioanalogue (-16.3), phosphorus chloride (-112), phosphorus oxychloride (-87), and thiophosphoryl chloride (-12). The principal semiaxes of molecular magnetic susceptibility ellipsoids (10²⁹ cm³) for the three latter compounds have been found equal: PCl₃ k₁ ?9.90, k _2,3 ?11.36; POCl₃ k_l ?8.83, k _2,3 ?11.28; PSCl₃ k₁ ?13.28, k_2,3, ?13.17. The components of the magnetic susceptibility tensors of the phosphorus lone pair kL ?2.15, k_t ?2.32 and of the bonds P-0 k_L ?4.35, k_T ?2.23; P-Cl k_L ?4.17, k_T ?2.05; P→O k_L ?1.11, k_T ?0.44; P→S k_L ?4.17, k_T ?2.17 have been calculated using data on the magnetic anisotropy effects on chemical shifts in PYR spectra of dioxaphosphorinanes. The relationship between the mean values of the magnetic susceptibility and electric polarizability phosphorus derivatives has been established, k = ?0.060–1.046.10^?5 b. The magnetic anisotropies of bonds have been shown to depend on their environment, for phosphoryl on the Kabachnik constants of substituents at the phosphorus atom.