The phosphinidene-bridged complexes [Mo2Cp2(mu-kappa(1):kappa(1),eta(6)-PR*)(CO)(2)] (1), [Mo2Cp2(mu-kappa(1):kappa(1),eta(4)-PR*)(CO)(3)] (2), [Mo2Cp(mu-kappa(1):kappa(1),eta(5)-PC5H4)(eta(6)-HR*)(CO)(2)] (3), and [Mo2Cp2(Mo2Cp2(mu-kappa(1):kappa(1),PH)(eta(6)-HR*)(CO)(2)] (4) were examined as precursors of heterometallic gold(I) and related derivatives (Cp = eta(5)-C5H5, R* = 2,4,6-(C6H2Bu3)-Bu-t). These complexes reacted with [AuCl(THT)] to give the corresponding derivatives [AuMo2ClCp2(mu-kappa(1):kappa(1),eta(PR)-P-6*)(CO)(2)], [AuMo2ClCp2(mu-kappa(1):kappa(1):kappa(1),eta(4)-PR*)(CO)(3)] (Au-Mo = 2.8493(6) angstrom), [AuMo2ClCp(mu-kappa(1):kappa(1):kappa(1),eta(5)-PC5H4)(CO)(2)(eta(6)-HR*)], and [AuMO2ClCp2(mu(3)-PH)(CO)(2)(eta(6)-HR*)] formally resulting from the addition of an acceptor Au Cl moiety to the short Mo-P bond of the parent substrates almost perpendicular to the corresponding Mo2P plane. The chloride ligand was easily displaced upon reaction of the PC6H4-bridged gold complex with- K[MoCp(CO)(3)] to give the tetranuclear derivative [AuMo3Cp2(mu-kappa(1):kappa(1),kappa(1),eta(5)-PC5H4)(CO)(5)(eta(6)-HR*)](Au-Mo = 2.711(2) and 2.807(2) angstrom). Compound 1 also reacted with HgI2 to give a hexanuclear complex [HgMo2Cp2(mu-I)I(mu-kappa(1):kappa(1),eta(6)-PR*)(CO)(2)](2) containing dative Mo -> Hg bonds (2.820(1) and 2.827(1) angstrom), whereas complex 3 gave the mu(3)-PR bridged complex HgMo2CpI2 (mu-kappa(1):kappa(1),kappa(1),eta(5)-PC5H4)(CO)(2)](2)(eta(6)-HR*)]. Complexes 1 to 4 also reacted easily with [AuL(THT)]PF6 (L = THT, P(p-tol)(3), PMe3, (PPr3)-Pr-i) to give the corresponding cationic trinuclear derivatives [AuMo2Cp2(mu-kappa(1):kappa(1),eta(6)-PR*)(CO)(2)L](PF6) (Au-Mo = 2.8080(3) angstrom for L = Pp-tol)(3)), [AuMo2Cp2(mu-kappa(1):kappa(1):kappa(1),eta(4)-PR*) (CO)(3)L] (PF6), and [AuMo2Cp(mu-kappa(1):kappa(1):kappa(1),eta(5)-PC5H4(CO)(2)(eta(6)-HR*){P(p-tol)(3)}](PF6). The blue, analogous PH-bridged complexes were more conveniently isolated as tetraarylborate salts [AuMo2CP2(mu(3)-PH)(CO)(2)(eta(6)-HR*)L](BAr'(4)) (Au-Mo = 2. 8038(6) angstrom for L = (PPr3)-Pr-i; Ar'= 3,5-C6H3(CF3)(2)]. Compounds 1, 3, and 4 reacted readily with the cation [Au(THT)(2)](+) (as PF6- or BAr'(-)(4) salts) in a 2:1 ratio to give respectively the corresponding pentanuclear derivatives [Au{Mo2Cp2 (mu-kappa(1):kappa(1):kappa(1),eta(6)-PR*)(CO)(2)}(2)](PF6), [Au{mo(2)Cp(mu-kappa(1):kappa(1):kappa(1),eta(5)-PC5H4)-(CO)(2)(eta(6)-HR*)}(2)](PF6) (Au-mo = 2.7975(7) and 2.8006(7) angstrom), and [Au{Mo2Cp2(mu(3)-PH)(CO)(2)(eta(6)-HR*)}(2)](BAr4') (Au-Mo = 2.8233(8) and 2.8691(7) angstrom). Related silver complexes were obtained from the reaction of 3 and 4 with [AgCl(PPh3)](4) after spontaneous symmetrization, while reaction of 1 with [Cu(NCMe)(4)]PF6 in a 2:1 ratio yielded the analogous copper complex [Cu(Mo2Cp2(mu-kappa(1):kappa(1):kappa(1),eta(6)-PR*)(CO)(2)}(2)](PF6). All the above cationic gold complexes having (mu-kappa(1):kappa(1):kappa(1),eta(6)-PR*) ligands (but not the copper complex) rearranged into [Au{Mo2Cp(mu-kappa(1):kappa(1):kappa(1),eta(5)-PC5H4)(eta(6)-HR*)}(2)](PF6) in refluxing 1,2-dichloroethane solution.