“Honeycomb” (6, 3) network constructed from 14-membered ring [Ag2(μ-dppb)2]: Synthesis, characterization and crystal structures of two silver(I) complexes of bis(diphenylphosphino)butane

Two new silver(I) complexes [Ag2(μ-dppb)2(CF3SO3)2] (1) and {[Ag2(dppb)3](CF3SO3)2•(4,4′-bipy)•(CH3CN)2}n (2) (dppb = bis(diphenylphosphino)butane, 4,4′-bipy = 4,4′-bipyridine) which contain dppb and trifluoromethanesulfonate anions have been synthesized and characterized by IR, X-ray crystallography, 1H NMR, 31P NMR spectroscopy and luminescence. Complex 1 and 4,4′-bipy reacted in the solution CH3CN to get complex 2. In the reaction, the 14-membered ring [Ag2(μ-dppb)2] of complex 1 is opened to form the “honeycomb” (6, 3) network structure of complex 2. In 2, each [Ag6(μ-dppb) 6] 6+ ring hosts two counterions, one 4,4′-bipy and two acetonitrile guest molecules.

Graphical abstractInduced by nitrogen heterocyclic ligands, [Ag2(dppb)2(CF3SO3)2] (1) was obtained. The 14-membered ring [Ag2(μ-dppb)2] of 1 is opened to form (6,3) network structure of {[Ag2(dppb)3](CF3SO3)2•(4,4′-bipy)•(CH3CN)2}n (2). In 2, each [Ag6(μ-dppb) 6] 6+ ring hosts CF3SO3−, 4,4’-bipy and acetonitrile molecules. 1–2 were characterized by IR, luminescence, 1H NMR, 31P NMR, and X-ray crystal diffraction.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The (6,3) network structure of 2 is formed by the ring-opening reaction of 1 with 4,4′-bipyridine. ► In 2, each [Ag6(μ-dppb) 6] 6+ macrocycle hosts CF3SO3- anions, 4,4′-bipy and acetonitrile molecules. ► The skeletons of silver(I)–dppb complexes are affected by the nitrogen heterocyclic ligands and the solvent. ► 1–2 exhibit strong fluorescence emission peaks at room temperature. ► The 31P NMR spectra of 1or 2 shows that the P atoms coordinated to the center Ag atom have different chemical environment.