Phosphorus-31 nuclear magnetic resonance parameters for compounds with the α-tetraphosphorus trisulphide skeleton; substituent constants for an inorganic substrate

Abstract

Phosphorus-31 n.m.r. spectra have been measured and assigned for symmetric compounds α-P₄S₃XY (1) with X = Y = Cl, Br, CN, or NCS, and for unsymmetric compounds (1) with X = CN, Y = Cl, Br, or I; X = N₃, Y = Cl; and X = Br, Y = I. Simple relationships between couplings in unsymmetric compounds and those in the corresponding symmetric compounds were found. Chemical shifts in the symmetric compounds were assigned by comparison with those assigned unambiguously in the unsymmetric compounds. All four coupling constants for the symmetric compounds were well fitted by two-parameter linear relationships involving substituent constants which, while based on organic reaction substituent constants, were substantially different from them.