An organocuprate(III) complex, [Cu-(TMS)PS3)(CH2CN)](-) (2), was identified along with a sequential derivative, [Cu((TMS)PS3)(CN)](-) (3), and an intermediate, [Cu((TMS)PS3)(HN=PPh3)] (4), formed in a relative transformation. Apical ligands among these complexes all strongly associate with a robust trigonal copper(III) platform. The nature of the ligand binding was spectroscopically and computationally investigated through a series of copper(III) complexes. The bonding along the principal C-3 axis is adaptable, and sigma interaction dominates the axial ligand coordination, where the cyanomethyl group exhibits the strongest bonding. Complex 2 is a scarce example of a thermostable aliphatic organocuprate(III) compound, which sheds some light on the organocopper(III) chemistry widely involved in many copper-mediated catalyses.