Electron-coupled spin–spin coupling tensor for 31P in tetraethyldiphosphine disulfide

The traceless part of the 31P–31P spin–spin coupling tensor was determined from a single crystal NMR study of tetraethyldiphosphine disulfide (TEPS). The electron-coupled part of this tensor, obtained by subtracting the known dipolar part, admits of two assignments. These have different anisotropies (δI = +1491 Hz, δII = +5861 Hz). Both show approximate axial symmetry (ηI = 0.1, ηII = 0.02) about the P–P bond, supporting the intuitive notion that J coupling is primarily determined by the local sigma-bonding electrons.