Construction of [Ag2X2]-based complexes from reactions of Ag(i) salts with N-diphenylphosphanylmethyl-4-aminopyridine: isolation, structures, and luminescent properties

Abstract

Reactions of N-diphenylphosphanylmethyl-4-aminopyridine (dppmapy) with K[Ag(CN)(2)], Ag(dca) (dca = dicyanamide), AgSCN, AgCl, AgBr or AgI gave rise to six [Ag(2)X(2)]-based (X = CN(-), dca, SCN(-), Cl(-), Br(-) and I(-)) compounds, [{Ag(2)(CN)(2)(dppmapy)}.0.5CHCl(3)](n) (1), [Ag(2)L(2)(dppmapy)(2)](n) (2: L = dca; 3: L = SCN), [{Ag(2)L(2)(dppmapy)(2)}.sol](n) (4: L = Cl, sol = 0.5MeOH.0.5CH(2)Cl(2); 5: L = Br, sol = 2CHCl(3)), and [Ag(2)I(2)(dppmapy)(4)].3MeOH (6). Complexes 1-6 were characterized by elemental analysis, IR, powder X-ray diffraction (PXRD), and single crystal X-ray diffraction. Compound 1 has a one-dimensional (1D) spiral chain constructed by bridging the [(CN)Ag(mu-CN)Ag] fragments via dppmapy ligands. In 2, 3 and 4, each [Ag(2)X(2)] (X = dca, SCN, Cl) fragment is linked by dppmapy bridges to the other two equivalent ones to form a 1D chain containing 16-membered rings (2) or a 1D double chain containing 20-membered rings (3) or a 1D spiral chain containing 20-membered rings (4). Compound 5 possesses a two dimensional (2D) (4,4) network consisting of 36-membered metallomacrocycles in which each [Ag(2)Br(2)] fragment acts as a unique planar four-connecting node to link the other four equivalent ones via dppmapy bridges. Complex 6 has a [Ag(2)I(2)] unit with a pair of monodentate dppmapy ligands coordinated at each Ag center. The photoluminescent properties of 1-6 in the solid state at ambient temperature were also investigated.