Polynuclear silver(I) complexes of diphosphine ligands and isoquinoline: Synthesis, structural characterization and spectroscopic properties

The reactions of diphosphine ligands and isoquinoline (i-C9H7N) with Ag salts in the mixed solvent of methanol (MeOH) and dichloromethane (CH2Cl2) generate the complexes [Ag2(dppm)2(NO2)2]·(i-C9H7N)2 (1), [Ag2(dppm)2(i-C9H7N)2(BF4)](BF4) (2), {[Ag(dppe)(i-C9H7N)2](CF3SO3)·(i-C9H7N)}n (3), {[Ag(dppb)(i-C9H7N)2](BF4)2·(i-C9H7N)0.5}n (4) and {[Ag(dppb)(i-C9H7N)(CF3SO3)]·(i-C9H7N)}n (5). These complexes were all characterized by IR, elemental analysis, X-ray diffraction, luminescence, 31P and 1H NMR spectroscopy. Complexes 1 and 2 have dinuclear structures, while complexes 3, 4 and 5 have 1D infinite zigzag chain structures. Complexes 1 and 2 are metal clusters in which there exist Ag⋯Ag metal bonds, whilst in compounds 3, 4 and 5, two silver atoms are bridged by the diphosphine ligands to form the 1D infinite zigzag chains. Complexes 3 and 5 are 2D topologically promising architectures and complex 4 is a 3D topologically promising architecture. In addition, complexes 1–5 exhibit interesting fluorescence in the solid state at room temperature. At the same time, we also studied the terahertz spectra of the complexes, which show more accurate characteristics of each group of complex.

Graphical abstractThe crystal packing of all five complexes shows that 1D infinite chains are self-assembled to construct the 2D or 3D supramolecular networks by hydrogen bonding. The choice of inorganic counter anions and co-ligands has great influence on the experimental results and terahertz spectra.Figure optionsDownload full-size imageDownload as PowerPoint slide