The crystal and molecular structure of the 2 : 1 triphenylphosphine copper(I) benzoate complex [(PPh3)2CuO2CC6H5] have been determined by a room-temperature single-crystal X-ray study. The complex is isomorphous with the dithiobenzoate analogue, crystallizing in the orthorhombic space group P212121 with a 20簹4(5), b 16繲9(9), c 10綵9(8) Ŭ Z 4; conventional R on |F| was 0簳9 for 4261 independent 'observed' (I > 3s(I)) reflections. Comparison of structural data for this and other [(PPh3)2CuO2CR] complexes shows that the P-Cu-P angle and the anion coordination are dependent on both the donor strength of the anion and on steric interactions between the anion and the triphenylphosphine ligands. The structure of the analogous nitrate complex [(PPh3)2CuNO3] has also been redetermined.