Reactions of the linear triplatinum complex [Pt-3(mu-dpmp)(2)(XylNC)(2)](2+) (3) with small organic molecules led to formation of asymmetrical A-frame triplatinum complexes with an additional bridge across one of the metal-metal bonds, where dpmp is bis((diphenylphosphino)methyl)phenylphosphine. Reaction of complex 3 with electron deficient alkynes (R(1)C=CR(2) : R(1) = R(2) = CO(2)Me; R(1) = H, R(2) = CO(2)Me; R(1) = R(2) = CO(2)Et) afforded a new series of triplatinum clusters formulated as [Pt-3(mu-dpmp)(2)(mu-R(1)CCR(2))(XylNC)(2)](PF6)(2) (5a, R(1) = R(2) = CO(2)Me; 5b, R(1) = H, R(2) = CO(2)Me; 5c, R(1) = R(2) = CO(2)Et) in good yields. The complex cation of 5b was characterized by X-ray crystallography to have an asymmetrical A-frame structure comprising three Pt atoms bridged by two dpmp ligands, in which an acetylene molecule was inserted into one of the Pt-Pt bonds (triclinic, , a = 19.507-(3) Angstrom, b = 20.327(4) Angstrom, c = 14.499(4) Angstrom, alpha = 107.69(2)degrees, beta = 102.08(2)degrees, gamma = 71.30(1)degrees, V = 5148 Angstrom(3), Z = 2, R = 0.070, and R(w) = 0.084). The Pt-Pt bond length is 2.718(1) Angstrom and the Pt ... Pt nonbonded distance is 3.582(1) Angstrom. Treatment of 3 with an excess of HBF4 . Et(2)O gave the asymmetrical cluster [Pt-3(mu-dpmp)(2)(mu-H)-(XylNC)(2)](BF4)(3) . CH2Cl2 (6 . CH2Cl2), in 61% yield, and a similar reaction with p-NO2C6H4NC led to the formation of [Pt-3(mu-dpmp)(2)(mu-R(3)NC)(XylNC)(2)](PF6)(2) . CH2Cl2 (7 . CH2Cl2) in 94% yield (R(3) = p-NO2C6H4). : R(1) = R(2) = CO(2)Me; R(1) = H, R(2) = CO(2)Me; R(1) = R(2) = CO(2)Et) afforded a new series of triplatinum clusters formulated as [Pt-3(mu-dpmp)(2)(mu-R(1)CCR(2))(XylNC)(2)](PF6)(2) (5a, R(1) = R(2) = CO(2)Me; 5b, R(1) = H, R(2) = CO(2)Me; 5c, R(1) = R(2) = CO(2)Et) in good yields. The complex cation of 5b was characterized by X-ray crystallography to have an asymmetrical A-frame structure comprising three Pt atoms bridged by two dpmp ligands, in which an acetylene molecule was inserted into one of the Pt-Pt bonds (triclinic, , a = 19.507-(3) Angstrom, b = 20.327(4) Angstrom, c = 14.499(4) Angstrom, alpha = 107.69(2)degrees, beta = 102.08(2)degrees, gamma = 71.30(1)degrees, V = 5148 Angstrom(3), Z = 2, R = 0.070, and R(w) = 0.084). The Pt-Pt bond length is 2.718(1) Angstrom and the Pt ... Pt nonbonded distance is 3.582(1) Angstrom. Treatment of 3 with an excess of HBF4 . Et(2)O gave the asymmetrical cluster [Pt-3(mu-dpmp)(2)(mu-H)-(XylNC)(2)](BF4)(3) . CH2Cl2 (6 . CH2Cl2), in 61% yield, and a similar reaction with p-NO2C6H4NC led to the formation of [Pt-3(mu-dpmp)(2)(mu-R(3)NC)(XylNC)(2)](PF6)(2) . CH2Cl2 (7 . CH2Cl2) in 94% yield (R(3) = p-NO2C6H4).