The First Metal Complexes Derived from 3,5-Diethynylpyridine. X-ray Crystal Structure of [(AuPTo3)2{μ-(C⋮C)2Py}] (Py = Pyridine-3,5-diyl; To =p-Tolyl)

The reactions of 3,5-diethynylpyridine (Py(C⋮CH) 2 ) with PPN[Au(acac) 2 ] (2.5:1; PPN = Ph 3 P N PPh 3 ) or with [AuCl(SMe 2 )] and NEt 3 (1:2:2) give respectively PPN[Au{C⋮C(Py)C⋮CH} 2 ] (1 ) and [Au 2 {μ-(C⋮C) 2 Py}] n ( 2 ). Complex 2 reacts with monodentate ligands (1:2) or with 1,6-bis(diphenylphosphino)hexane (dpph, 1:1) to give neutral dinuclear complexes of the general formula [(AuL) 2 {μ-(C⋮C) 2 Py}] (L = CN t Bu ( 3 ), PMe 3 ( 4 ), PPh 3 ( 5 ), PTo 3 (To = C 6 H 4 Me-4) ( 6 ); Au 2 L 2 = Au 2 (μ-dpph) ( 7 )). The reactions of 6 with the complexes [MCl] and TlTfO (1:1:1) (TfO = CF 3 SO 3 ) give the cationic trinuclear complexes [M{Py(C⋮CAuPTo 3 ) 2 }]TfO (M = AuPTo 3 ( 8 ), cis- PtCl(PPh 3 ) 2 ( 9 )). The crystal structure of complex 6 has been determined.