Synthesis, spectral and structural studies of silver and gold(I) complexes containing some symmetrical diphosphine ligands

New silver(I) and gold(I) complexes [Ag3(μ2-CN)3(κ2-P,P-dppf)2]n·C6H12 (1), [Ag4(μ2-CN)4(κ1-P,P-dtbpf)]n (2), [Au2(μ1-CN)2(κ1-P,P-dppf)] (3), [Au2(μ1-CN)2(κ1-P,P-dtbpf)] (4), [Ag4(μ3-CN)2(μ1-CN)2(κ1-P,P-dcpf)2] (5), and [Au2(μ1-CN)2(κ1-P,P-dcpf)] (6) were prepared starting with MCN (M = Ag, Au) and dppf/dtbpf/dcpf (dppf = 1,1′-bis(diphenylphosphino) ferrocene; dtbpf = 1,1′-bis(di-tert-butylphosphino) ferrocene; dcpf = 1,1′-bis(dicyclohexylphosphino) ferrocene) in 1:1 M ratio in DCM:MeOH (50:50 V/V) at room temperature. The resulting complexes have been characterized by elemental analysis, IR, 1H & 31P NMR, ESI-MS and electronic absorption spectroscopy. Molecular structures for the complexes 1, 2, 5, and 6 were determined crystallographically. Complex 1 and 2 exist as an infinite one-dimensional (1D) polymeric chain constructed by [(μ2-CN)Ag(μ2-CN)Ag] fragments bridged via dppf/dtbpf ligands. The molecular structure of 5 reveals a centrosymmetric dimeric complex in which the two silver atoms are bonded to two dcpf ligands in κ1 manner and two cyanide groups in a μ3 bonding mode to generate nearly planar Ag2(μ3-CN)2 framework, while complex 6 exists in open bridging mode containing Au atoms in ideal linear coordination defined by P,CN-donor sets.