REACTIONS OF [AU(ACAC)PPH3] WITH DIPHOSPHINE DERIVATIVES - DIFFERENT COORDINATION MODES OF GOLD TO THE LIGAND SYSTEMS - X-RAY STRUCTURE OF [SPPH2C(AUPPH3)2PPH2CH(AUPPH3)COOME]CLO4 AND [AU5(C6F5)((SPPH2)2C-]2(PPH3)]

Reactions of various diphosphine ligands with [Au(acac)PPh3] (acac = acetylacetonate) are reported. In all cases the ligand is deprotonated by displacement of acac as acetylacetone and subsequently coordinates the gold or the AuPPh3+ fragment. The reaction of the diphosphines Ph2PNHPPh2 (dppa) or Ph2PCH2PPh2 (dppm) with [Au(acac)PPh3] leads to the dinuclear complexes [Au(PPh2)2N]2 (1) or [Au(PPh2)2CH]2 (2), with the diphosphines acting as bridging ligands. With the diphosphine disulfides SPh2PNHPPh2S or SPh2PCH2PPh2S the reaction takes place in a different manner; with SdppaS the dinuclear complex [Au(SPPh2)2N]2 (3) is formed, while with SdppmS a mixture of [(SPPh2)2CH(AuPPh3)] (4) and [(SPPh2)2C(AuPPh3)2] (5) is obtained. If the reaction is carried out with 2 equiv of [Au(acac)PPh3], only the disubstituted product 5 is isolated. The mixed phosphine sulfide-phosphonium derivatives [SPPh2CH2PPh2R]ClO4 (R = Me, CH2Ph, CH2COOMe) react with [Au(acac)PPh3] in different stoichiometries to give the deprotonated mononuclear [SPPh2CH(AuPPh3)PPh2R]ClO4 (R = Me (6)), dinuclear [SPPh2C(AuPPh3)2PPh2R]ClO4 (R = Me (7), CH2Ph (8), CH2COOMe (9)), or the trinuclear [SPPh2C(AuPPh3)2PPh2CH(AuPPh3)COOMe]ClO4 (10) (R = CH2COOMe). The reactivity of these methanide complexes toward gold or silver complexes which possess a labile ligand such as tht in [Au(C6F5)tht] (tht = tetrahydrothiophene) or ClO4 in AgClO4 is different. Complex [SPPh2CH(AuPPh3)PPh2Me]ClO4 reacts with [Au(C6F5)tht] or AgClO4 leading to the dinuclear derivatives [Au2(SPPh2CHPPh2Me)2](ClO4)2 (11) or [AuAg(SPPh2CHPPh2Me)2](ClO4)2 (12), and the compounds [Au(C6F5)PPh3] or [Au(PPh3)2]ClO4 are formed as byproducts. Treatment of the complex [(SPPh2)2C(AuPPh3)2] with 2 equiv of [Au(C6F5)tht] gives the pentanuclear complex [Au5(C6F5){(SPPh2)2C}2PPh3] (13). Single-crystal X-ray structure determinations were performed for compounds 10 and 13. [SPPh2C(AuPPh3)2PPh2CH(AUPPh3)COOMe]ClO4 (10) crystallizes in space group P1BAR, triclinic, with a = 14.448(4) angstrom, b = 16.645(4) angstrom, c = 17.780(5) angstrom, alpha = 97.26(2)degrees, beta = 93.76(2)degrees, gamma = 89.71(2)degrees, Z = 2. [Au5(C6F5){(SPPh2)2C}2PPh3] (13) crystallizes in space group P1BAR, triclinic, a = 11.900(11) angstrom, b = 18.425(27) angstrom, c = 18.877(17) angstrom, alpha = 87.85(10)degrees, beta = 86.34(8)degrees, gamma = 79.38(10)degrees, Z = 2.