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), w hereas 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)-deg rees) exhibits the expected linear coordination with the azine acting as N-monodentate ligand. Bond parameters of interest are Au-C(perfluor ophenyl) 1.992(6), Au-N(azine) 2.069(5) angstrom, C-Au-N 175.8(2)-degr ees. 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)-de grees) is an ionic species in which the cation is the monoprotonated d erivative of the azine coordinated to gold in 2. Bond parameters withi n the azine molecule in the two derivatives are comparable. Complex 1 promotes dinitrogen elimination from diazofluorene to form fluoren-9-y lidene via carbene-carbene coupling. An interpretation of the differen t behaviour of the two diazocompounds is presented.