Synthesis and characterization of novel S,N and Se,N homodimetallic Ag(i)-complexes

Abstract

Novel C2-symmetric doubly bidentate Se,N and S,N-ligands based on a readily available Tröger's base backbone were synthesized and fully characterized. Their coordination properties were studied in dinuclear Ag(I)-complexes employing ¹H, ⁷⁷Se and ¹H–¹⁵N HETCOR NMR spectroscopy as well as X-ray diffraction crystallography. In solution, a single ligand can accommodate two silver atoms by coordination to nitrogen and sulfur or selenium. The investigations in the solid state revealed the presence of a pentacoordinated silver atom (NSO₃ and N₃Se₂ donor sets are influenced by the solvent employed during the crystallization). In the solid state, the Ag(I)-complex with the S,N-ligand 2b forms dimeric structures bridged by the two perchlorate counterions. The analogous Se,N-ligand 2c coordinates to Ag(I) and forms polymeric enantiomerically pure helices, although the crystal is racemic.