The triflate and hexafluorophosphate salts of [Cu-2(mu-dtbpm)(2)](2+) (1(2+)) [dtbpm = bis(di-tert-butylphosphino)methane, (Bu2PCH2PBu2)-Bu-1-Bu-t] and of [Cu-3(mu(3)-F)(mu-dtbpm)(3)](2+) (2(2+)) were synthesized and characterized. Coordination of solvent or counterions to 1(2+) is observed neither in solution nor in the solid state, The two copper(I) centers in 1(2+) indicate weak d(10)-d(10) closed-shell interactions. 1(2+) reacts slowly with PF6- anions in acetone or KF in CH2Cl2 to yield the mu(3)-fluorido complex 2(2+) with idealized Dg symmetry, containing a trigonal planar Cu3F core, as shown by single-crystal X-ray diffraction. Distinct structural differences are observed compared to monocationic bicapped, trinuclear copper(I) dppm halide complexes [dppm = bis(diphenylphosphino)methane, Ph2PCH2PPh2]. The average Cu-Cu, Cu-F, and Cu-P distances and the P-Cu-P' angle in 2(2+) are 3.85, 2.22, and 2.28 Angstrom and 144.3 degrees, respectively. The P2Cu units are twisted out of the Cu3F plane by an average angle of 18.4 degrees. DFT calculations (BPW91/LANL2DZ) for the model [Cu-3(mu(3)-F)(mu-dhpm)(3)](2+) (dhpm = diphosphinomethane, H2PCH2PH2) are used to explain the formation, structure, and bonding pattern of 2(2+).