Several new heterobimetallic hydrides containing gold have been synthesized. [Au2Os(H)3(PPh3)5]PF6 (1) was made by the reaction of AuPPh3NQ3 and Os(H)4(PPh3)3 with CH2C12 as solvent. [Au2Ru(H)3(PPh3)5]PF6 (2) was synthesized in an analogous manner from AuPPh3NQ3 and Ru(H)4(PPh3)3 with toluene as solvent. [AuRu(H)2(CO)(PPh3)4]PF6 (3) and its osmium analogue, [AuOs(H)2(CO)(PPh3)4]PF6 (4), and [AuOs(H)2(CO)2(PPh3)3]PF6 (5) and its ruthenium analogue, [AuRu(H)2(CO)2(PPh3)3]PF6 (6), were prepared by the reaction of AuPPh3N03 with M(H)2(CO)(PPh3)3 (M = Ru, Os) and M(H)2(CO)2(PPh3)2 ( = Ru, Os), respectively, with CH2C12 as solvent. Compounds 1 and 3 were characterized by single-crystal X-ray diffraction in the solid state [l-3CH2Cl2.2Et20, monoclinic P2¡/n, a = 13.64 (2) A, b = 40.89 (2) k,c= 17.53 (1) A, ß = 102.54 (9)°, = -116 °C, Z = 4,R = 0.051 for 10 180 observations; 3-2CH2Cl2, triclinic PI, a = 15.404 (3) A, b = 19.461 (8) A, c = 13.868 (7) k, a = 98.86 (4)°, ß -105.68 (3)°, y = 87.73 (2)°, T = 22 °C, Z = 2, R = 0.051 for 9648 observations] and by 31P and NMR spectroscopy in solution. The structure of complex 1 consists of two Au(PPh3) units bonded to an Os(PPh3)3 moiety forming a slightly distorted trigonal-bipyramidal geometry with no Au-Au bond (4.28 A). The hydride ligands were not directly observed by X-ray diffraction in 1; however, spectroscopic evidence indicates the presence of one hydride bridging each of the Au-Os bonds on the outside edges of the Au2Os triangle and a third hydride briding one of the Au-Os bonds on the inside edge of the Au2Os triangle. Supporting evidence for the characterization of complex 1 in the solid state was obtained with the use of CP MAS 31P NMR spectroscopy. In the X-ray diffraction analysis of complex 3 one of the hydride ligands was directly observed bridging the Au-Ru bond. Spectroscopic evidence supports the formulation of 3 as a bis(g-hydrido) species. The average Au-Os and Au-Ru distances in 1 and 3 are 2.703 (0) and 2.786 (1) A, respectively, and the Ru-H and Au-H separations in 3 are 1.78 (4) and 1.61 (4) A, respectively. Compounds 2 and 4-6 were also determined to have bridging hydrides by NMR and IR spectroscopy. Preliminary results indicate that the gold adduct [AuRu(H)2(CO)(PPh3)4]PF6 (3) has a significantly higher rate of catalytic activity than its parent complex, Ru(H)2(CO)(PPh3)3, for the isomerization of 1-hexene to cis-and trans-2-hexene in CH2C12 at 25 °C and 1 atm of N2.