The flash photolysis of phosphine

Abstract

The equation representing the decomposition of phosphine by flash photolysis is shown to be PH 3 → P red + 3/2H 2 . The phosphorus is produced in the form of small particles which remain suspended in the gas phase for several minutes provided that the total pressure is high enough. The variation with time of the spectra of PH 2 , PH and P 2 has been studied and the secondary reactions consequent upon the photolysis are shown to be homogeneous. The P 2 is produced in a vibrationally excited state at room temperature, transitions involving levels of up to v' = 7 being observed. A mechanism for the photolysis and the production of excited P 2 is proposed.