Abstract

Phosphine, PH₃, was discovered over 200 years ago but the first, large-scale production of this compound and its derivatives did not begin until the mid- to late 1970s. The delay was due largely to the pyrophoric and highly toxic nature of phosphine which requires specialized technology for safe handling. Nevertheless, two viable manufacturing processes were eventually invented, patented (in 1961 and 1962), and later commercialized.

This article describes these processes and compares their advantages and disadvantages. However, more emphasis is given to the growing number of applications for this relatively new and versatile class of specialty chemicals. Phosphine itself is used both as a dopant in semiconductors and as a fumigant for grain silos. The former requires high purity or electronic-grade phosphine, whereas in the latter case, less pure phosphine is employed as a 2% mixture with carbon dioxide. The derivatives of phosphine, such as alkylphosphinic acids, phosphine oxides, and phosphonium salts find utility as textile flame retardants, mining chemicals, solvent extraction reagents, biocides, phase-transfer catalysts, and uv photoinitiators. The chemistry involved in the synthesis of these compounds is discussed in addition to the applications.