Just as the amines are derived from ammonia, so from phosphine are derived the primary, secondary and tertiary organic phosphines by the exchange of hydrogen for alkyl groups, and corresponding to the phosphonium salts there exists a series of organic phosphonium bases.
The tertiary phosphines, discovered by L.
The primary and secondary phosphines are colourless compounds, and with the exception of methyl phosphine are liquid at ordinary temperature.
The primary phosphines are very weak bases, their salts with acids being readily decomposed by water.
The tertiary phosphines are characterized by their readiness to pass into derivatives containing pentavalent phosphorus, and consequently they form addition compounds with sulphur, carbon bisulphide, chlorine, bromine, the halogen acids and the alkyl halides with great readiness.