Non-Metal Derivatives of the Bulkiest Known Tertiary Phosphine, Trimesitylphosphine

Abstract

Trimesitylphosphine (Pmes₃) is the bulkiest known tertiary phosphine. The low yield synthesis of this known compound, its failure to form a carbon disulfide adduct or a selenide derivative, the relatively low values for v(P—O), v(P—S) and v(P—H) in its oxide, sulfide and phosphonium salt respectively, and the high barriers to rotation about the P—C_ipso bond in Pmes₃, and its derivatives all attest to this fact. Nevertheless, Pmes₃, does show chemistry typical of most tertiary phosphines due to its relatively high basicity and the electronic character of even this most bulky phosphine must also be considered in any discussion of its chemistry.

Key Words:

• Tertiary phosphine
• triaryl phosphine
• steric effect
• electronic effect