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, Bus, But, 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.