The reaction of syn-[Pt-2(mu-dpmp)(2)(XylNC)(2)](PF6)(2) (1) with AuPF6 yielded the Pt2Au trinuclear complex [Pt2Au(mu-dpmp)(2)(XylNC)(2)](PF6)(3) (7) in 60% yield. The structure was determined by X-ray crystallography to comprise a Pt2Au trinuclear core bridged by two dpmp ligands (7 .(CH3)(2)CO : monoclinic, P2(1)/n (No. 14), a = 15.147(3) Angstrom, b = 25.947(8) Angstrom, c = 25.759(6) Angstrom, beta = 104.10(2)degrees, V = 9818 Angstrom(3), Z = 4, D-calcd = 1.593 g cm(-3), R = 0.065, and R(w) = 0.059). An Au(I) ion is trapped by two uncoordinated phosphine units in 1 to lead a deformed Pt-Pt-Au aggregation. The Pt-Pt and Pt ... Au distances are 2.708(2) and 3.045(2) Angstrom, respectively, and the Pt-Pt ... Au angle is 110.68(5)degrees. The similar Pt2Ag cluster, [Pt2Ag(mu-dpmp)(2)(XylNC)(2)](PF6)(3) (8), was also prepared by the reaction of complex 1 with AgPF6 in 70% yield. The crystal structure is essentially identical to that of 7 (monoclinic, C2/c(No. 15), a = 18.302(6) Angstrom, b = 25.056(6) Angstrom, c = 47.172(9) Angstrom, beta = 99.11(3)degrees, V = 21359 Angstrom(3), Z = 8, D-calcd = 1.373 g cm(-3), R = 0.089, and R(w) = 0.078). The Pt-Pt and Pt ... Ag distances are 2.657(2) and 3.118(3) Angstrom, respectively, and the Pt-Pt ... Ag angle is 136.36(8)degrees. Reactions of 1 with CuX (X = I, Pr, Cl) gave yellow complex [Pt(2)CuX(mu-dpmp)(2)(XylNC)(2)](PF6)(2) (9, X = I; 10, X = Pr; 11, X = Cl), in good yield (9 . Et(2)O : monoclinic, P2(1)/c (No. 14), a = 15.048(4) Angstrom, b = 21.922(3) Angstrom, c = 27.840(3) Angstrom, beta = 101.89(1)degrees, V = 8987 Angstrom(3), Z = 4, D-calcd = 1.641 g cm(-3), T = 23 degrees C, R = 0.056, and R(w) = 0.046. 10 . Et(2)O : monoclinic, P2(1)/c (No. 14), a = 14.910(4) Angstrom, b = 21.891(7) Angstrom, c = 27.226(8) Angstrom, beta = 101.66(6)degrees, V = 8702 Angstrom(3), Z = 4, D-calcd = 1.658 g cm(-3), T = -95 degrees C, R = 0.042, and R(w) = 0.046. 11 . Et(2)O : monoclinic, P2(1)/c (No. 14), a = 15.037(4) Angstrom, b = 22.081(6) Angstrom, c = 27.449(4) Angstrom, beta = 101.92(2)degrees, V = 8917 Angstrom(3), Z = 4, D-calcd = 1.585 g cm(-3), T = 23 OC, R = 0.040, and R(w) = 0.041). The Pt(2)CuX assembly forms a rhombic structure with the Pt-Pt, Pt ... Cu, Cu-X, and Pt ... X distances being 2.715-2.727, 2.857-2.872, 2.276-2.597, and 3.088-3.130 Angstrom, respectively. The CuI fragment is trapped by the pendant phosphorus arms of 1. The Pt ... Cu-X angle is interestingly less than 90 degrees, resulting in a relatively short interatomic distance between the terminal Pt and X atoms. A monovalent group 11 metal ion (Au(I), Ag(I), or Cu(I)), which has a d(10) configuration, was readily incorporated into the Pt-2 core, leading to a heterotrimetallic Pt(2)M aggregation.