Three heterometallic Au-Pt complexes [Pt-2(PPh3)(4)(mu -S)(mu (3)-S)AU(PPh3)][PF6] (2), [Pt-2(PPh3)(4)(mu (3)-S)(2)Au-2(mu -dppm)]-[PF6](2) (3), and [Pt-2(PPh3)(4)(mu (3)-S)(2)Au-2(mu -dppf)][PF6](2) (4) have been synthesized from Pt-2(PPh3)(4)(mu -S)(2) (1) [dppm = Ph2PCH2PPh2; dppf = (C5H4PPh2)(2)Fe] and characterized by single-crystal X-ray crystallography. In 2, the Au(I) atom is anchored on only one of the sulfur centers. In 3 and 4, both sulfur atoms are aurated, showing the ability of 1 to support an overhead bridge structure, viz. [Au-2(P-P)], with or without the presence of Au-Au bond. The change of dppf to dppm facilitates such active interactions. Two stereoisomers of complex 3 (3a,b) have been obtained and characterized by single-crystal X-ray crystallography. NLDFT calculations on 2 show that the linear coordination mode is stabilized with respect to the trigonal planar mode by 14.0-kJ/mol. All complexes (2-4) are fluxional in solution with different mechanisms. In 2, the [Au(PPh3)] fragment switches rapidly between the two sulfur sites. Our hybrid MM-NLDFT calculations found a transition state in which the Au(I) bears an irregular trigonal planar geometry (DeltaG(double dagger) = 19.9 kJ/mol), as well as an intermediate in which Au(I) adopts a regular trigonal planar geometry. Complexes 3a,b are roughly diastereoisomeric and related by sigma (minor plane) conversion. This symmetry operation can be broken, down to two mutually dependent fluxional processes: (i) rapid flipping of the dppm methylene group across the molecular plane defined by the overhead bridge; (ii) rocking motion of the two Au atoms across the S . . .S axis of the {Pt2S2} core. Modeling of the former by molecular mechanics yields a steric barrier of 29.0 kJ/mol, close to that obtained from variable-temperature P-31{H-1} NMR study (33.7 kJ/mol). In 4, the twisting of the ferrocenyl moiety across the S S axis is in concert with a rocking motion of the two gold atoms. The movement of dppf is sterically most demanding, and hence, 4 is the only complex that shows astatic structure at lower temperatures. Pertinent crystallographic data: (2) space group P1, a = 15.0340(5) Angstrom, b = 15.5009(5) Angstrom, c = 21.9604(7), Angstrom, alpha = 74.805(1)degrees, beta = 85.733(1)degrees, gamma = 78.553(1)degrees, R = 0.0500; (3a) space group Pna2(1), a = 32.0538(4) Angstrom, b = 16.0822(3) Angstrom, c = 18.9388(3) Angstrom, R = 0.0347; (3b) space group Pna2(1),a = 31.950(2) Angstrom, b, 16.0157(8) Angstrom, c = 18.8460(9) Angstrom, R = 0.0478; (4) space group P2(1)/cl a = 13.8668(2) Angstrom, b = 51.7754(4) Angstrom, c = 15.9660(2) Angstrom, beta 113.786(1)degrees, R = 0.0649.