The dinuclear Au(I) amidinate complex AU(2)(2,6-Me2Ph-form)(2) (1) is isolated in quantitative yield by the reaction of (THT)AuCl and the potassium salt of 2,6-Me2Ph-form in a 1:1 stoichiometric ratio. Various reagents such as Cl-2, Br-2, I-2, CH(3)l, and benzoyl peroxide add to the dinuclear Au(I)amidinate complex AU(2)(2,6-Me2Ph-form)(2) to form oxidative-addition Au(II) metal-metal-bonded complexes 2, 3, 4, 5, and 6. The Au(II) amidinate complexes are stable as solids at room temperature. The structures of the dinuclear Au-2(2,6-Me2Ph-form)(2) and the Au(II) oxidative-addition products Au-2(2,6-Me2Ph-form)(2)X-2, X = Cl, Br, I, are reported. Crystalline products with an equal amount of oxidized and unoxidized complexes in the same unit cell, [Au-2(2,6-Me2Ph-form)(2)X-2][Au-2(2,6-Me2Ph-form)(2)], X = Cl, 2m, or Br, 3m, are isolated and their structures are presented. The structure of [Au-2(2,6-Me2Ph-form)(2)X-2][Au-2(2,6-Me2Ph-form)(2)], X = Cl has a Au(II)-Au(II) distance slightly longer, 0.05 angstrom, than that observed in the fully oxidized product Au-2(2,6-Me-2-form)(2)Cl-2, 2. The gold gold distance in the dinuclear complex decreases upon oxidative addition with halogens from 2.7 to 2.5 angstrom, similar to observations made with the Au(I) dithiolates and ylides. The oxidative addition of benzoyl peroxide leads to the isolation of the first stable dinuclear Au(II) nitrogen complex possessing Au-O bonds, Au-2(2,6-Me2Ph-form)(2)(PhCOO)(2), 6, with the shortest Au-Au distance known for Au(II) amidinate complexes, 2.48 angstrom. The structure consists of unidentate benzoate units linked through oxygen to the Au(II) centers. The replacement of the bromide in 3 by chloride, and the benzoate groups in 6 by chloride or bromide also occurs readily. The unit cell dimensions are, for 1, a = 7.354(6) angstrom, b = 9.661(7) angstrom, c 11.421(10) angstrom, alpha = 81.74(5)degrees, beta = 71.23(5)degrees, and gamma = 86.07(9)degrees (space group P (1) over bar, Z = 1), for 2 center dot 1.5C(6)H(12), a = 11.012(2) angstrom, alpha = 18.464(4) angstrom, c = 19.467(4) angstrom, alpha = 90 degrees, beta = 94.86(3)degrees, and gamma = 90 degrees (space group P2(1)/c, Z = 4), for 2m center dot ClCH2CH2Cl, a = 16.597(3) angstrom, b = 10.606(2) angstrom, c = 19.809(3) angstrom, alpha = 90 degrees, beta = 94.155(6)degrees, and gamma = 90 degrees (space group P2(1)/n, Z = 2), for 3m, a 16.967(3) angstrom, b = 10.783(2) angstrom, c = 20.060(4) angstrom, alpha = 90 degrees, beta = 93.77(3)degrees, and gamma = 90 degrees (space group P2(1)/n, Z = 2), for 4 center dot THF, a = 8.0611(12) angstrom, b = 10.956(16) angstrom, c = 11.352(17) angstrom, alpha = 84.815(2)degrees, beta= 78.352(2)degrees, and gamma= 88.577(2)degrees (space group P (1) over bar, Z = 1), for 5, a = 16.688 angstrom, b = 10.672(4) angstrom, c = 19.953(7) angstrom, alpha = 90.00 (6)degrees, beta = 94.565(7)degrees, and gamma = 90.00 degrees (space group P2(1)/n, Z = 4), for 6 center dot 0.5C(7)H(8), a = 11.160(3), angstrom, b 12.112(3) angstrom, c = 12.364(3) angstrom, alpha = 115.168(4)degrees, beta = 161.112(4)degrees, and gamma = 106. 253(5)degrees (space group P (1) over bar, Z =1).
