The preparation of phosphonium iodide is usually effected by the hydrolysis of an intimate mixture of diphosphorus tetraiodide and white phosphorus. [Ref.1, Ref.2]
10P2I4 + 13P4 + 128H2O → 40PH4I + 32H3PO4
Standard molar enthalpy (heat) of formation ΔfH0 (298.15 K, kJ/mol):
-82.8 (s)
References:
Ефимов А.И. и др. Свойства неорганических соединений. Справочник. - Л.: Химия, 1983. - pp. 208-209 [Russian]
Некрасов Б.В. Основы общей химии. - Т.1. - М.: Химия, 1973. - pp. 455 [Russian]