Phosphorus–nitrogen compounds. Part 56. The solution synthesis of some trans-1,3-dialkyl-2,4-diphenyl-2,4-dithiocyclodi-λ5-phosphazanes and their proton, carbon-13, and phosphorus-31 nuclear magnetic resonance spectra

Abstract

A series of trans-1,3-dialkyl-2,4-diphenyl-2,4-dithiocyclodi-λ⁵-phosphazanes, [PhP(S)NR]₂(R = Me, Et, Prⁿ, Prⁱ, Buⁿ, Buⁱ, Bu^s, Bu^t, neopentyl, CH₂Ph, or cyclohexyl) has been synthesized by a solution method and their proton, carbon-13, and phosphorus-31 n.m.r. spectra obtained. The relationships between phosphorus-31 and carbon-13 n.m.r. chemical shift data are explored; interpretation of proton n.m.r. data has led to the assignment of trans structures for the cyclodi-λ⁵-phosphazane molecules. Inductive and resonance substituent coefficients have been evaluated using the dual-substituent parameter method from the relative shieldings of the meta- and para-carbon nuclei in the phenyl ring.