REACTIONS OF [AU(C6F5)(SC4H8)] WITH DIAZOALKANES - SYNTHESIS AND MOLECULAR-STRUCTURES OF [AU(C6F5)(PH2C=N-N=CPH2)]

Treatment of [Au(C6F5)(SC4H8)] (1) (SC4H8 = tetrahydrothiophene, tht) with Ph2CN2 affords the azine complex [Au(C6F5)(Ph2C=N-N=CPh2)] (2), whereas HAuCl4 reacts with diphenyldiazomethane to form the salt [Ph2C=N(H)-N=CPh2][AuCl4] (3). The molecular structures of both 2 and 3 have been established by single crystal X-ray diffraction studies. Complex 2 (triclinic, P1BAR, Z = 2, a = 10.805(4), b = 13.066(2), c = 10.094(3) angstrom, alpha = 112.06(3), beta = 100.63(2), gamma = 88.45(2)-degrees) exhibits the expected linear coordination with the azine acting as N-monodentate ligand. Bond parameters of interest are Au-C(perfluorophenyl) 1.992(6), Au-N(azine) 2.069(5) angstrom, C-Au-N 175.8(2)-degrees. 3 (triclinic, P1BAR, Z = 1, a = 9.145(5), b = 9.333(1), c = 8.228(3) angstrom, alpha = 100.08(1), beta = 107.30(3), gamma = 74.17(2)-degrees) is an ionic species in which the cation is the monoprotonated derivative of the azine coordinated to gold in 2. Bond parameters within the azine molecule in the two derivatives are comparable. Complex 1 promotes dinitrogen elimination from diazofluorene to form fluoren-9-ylidene via carbene-carbene coupling. An interpretation of the different behaviour of the two diazocompounds is presented.