Solid-state ³¹P n.m.r., far-i.r. spectroscopy and single-crystal X-ray diffraction techniques have been used to characterize a new type of ionic copper(I) compound: [PPh₃Me][Cu(PPh₃)Br₂]. X-Ray analysis shows the PPh₃ ligand to be co-ordinated to the copper atom of the CuBr₂ unit in a trigonal planar arrangement, with Cu–P 2.210(3), Cu–Br 2.367(2), 2.386(2)Å and Br–Cu–Br 114.9(1)°{monoclinic, space group Pn, a= 11.779(5), b= 9.914(5), c= 14.705(10)Å, β= 94.92(5)°, Z= 2, R= 0.037 for 1 570 ‘observed’[I > 3σ(I)] reflections}. The far-i.r. spectrum shows a strong band at 195 cm^–1 assigned to the antisymmetric Cu–Br stretching mode of the CuBr₂ unit, and a weaker band at 150 cm^–1 assigned to the symmetric Cu–Br stretching mode. This assignment is supported by an approximate normal-co-ordinate analysis, and the resulting Cu–Br force constant is compared with values obtained in similar analyses of related bromocopper(I) complexes. The cross-polarization magic angle spinning ³¹P n.m.r. spectrum shows a strong signal at 21 p.p.m. (relative to 85% H₃PO₄) due to the cation, and a weaker quartet centred at –14 p.p.m. due to the co-ordinated PPh₃ in the anion, with line spacings due to Cu–P coupling of 1.37, 1.69, and 1.92 kHz.