Iodophosphonium Salts with Unusual Properties and a Structural Alternative for Halophosphoranes

Abstract

The NMR spectroscopically monitored course of the reaction of t Bu 3 P with I 2 in CH 2 Cl 2 is most unusual: no separate signals are found for the products, and the continuous changing of the chemical shifts and coupling constants does not cease at the “equivalence point” ( t Bu 3 PI: I 2 = 1:1). This can be explained in terms of the equilibria (a)–(c). Also unusual is the structure of t Bu 3 PI 2 in the solid state: t Bu 3 PII. equation image