Organophosphines are organophosphorus compounds with the formula PRnH3−n, where R is an organic substituent. These compounds can be classified according to the value of n: primary phosphines (n = 1), secondary phosphines (n = 2), tertiary phosphines (n = 3). All adopt pyramidal structures.[1] Organophosphines are generally colorless, lipophilic liquids or solids.[2] The parent of the organophosphines is phosphine (PH3). [3]