The Cu(I) complexes, (Ph₃P)₂CuL (L = [S₂PMe₂]^-, [OSPR₂]^- (R = Me, Ph), [(XPR₂)(YPR'₂)N]^- (X, Y, R, R' = O, O, Ph, Ph; O, S, Ph, Ph; O, S, OEt, Ph; S, S, Me, Me)) and Cu(II) complexes, CuL₂ (L = [(XPR₂)(YPR'₂)N]^- (X, Y, R, R' = O, O, Ph, Ph; O, S, Ph, Ph)), have been prepared. The Cu(I) derivatives were characterized by multinuclear NMR spectroscopy and in two cases by X-ray crystallography. (Ph₃P)₂Cu[S₂PMe₂] (1) crystallizes in the orthorhombic space group P2₁2₁2₁ (No. 19) with cell parameters a = 9.782(2), b = 17.808(4), c = 20.216(4) Å, V = 3521(6) ų and Z = 4, and (Ph₃P)₂Cu[(OPPh₂)₂N] (4) in the triclinic space group P[Formula: see text] (No. 2) with cell parameters a = 9.8079(2), b = 12.9141(3), c = 22.5666(5) Å, α = 75.714(2), β = 79.465(2), γ = 68.2770(8)°, V = 2559.9(1) ų and Z = 2. In both cases the phosphorus ligands are bidentate, thus resulting in monomeric molecules that contain tetrahedral CuP₂S₂ and CuP₂O₂ cores. The molecular structures of two of the Cu(II) derivatives were also determined. Cu[(OPPh₂)₂N]₂ (8) and Cu[(OPPh₂)(SPPh₂)N]₂ (9) crystallize in the triclinic space group P[Formula: see text] (No. 2) with cell parameters a = 8.887(2), b = 10.739(2), c = 12.477(3) Å, α = 77.61(3), β = 76.15(5), γ = 79.46(3)°, V = 1118.3(4) ų and Z = 1 for 8, and a = 9.626(2), b = 14.151(3), c = 24.752(5) Å, α = 88.23(3), β = 79.93(3), γ = 89.77(3)°, V = 3181(1) ų and Z = 3 for 9. The molecule of Cu[(OPPh₂)₂N]₂ (8) has a planar CuO₄ core, while in Cu[(OPPh₂)(SPPh₂)N]₂ (9) both planar and tetrahedral copper cores are observed in a ratio of 1:2.Key words: structure, copper, thiophosphinates, oxo- and thio-imidodiphosphinates