Novel silver(I)–saccharinate complexes exhibiting Ag···π and C–H···Ag close interactions with a new coordination mode of saccharinate

Abstract

Two novel silver(I) complexes, namely [Ag2(μ3-sac)2(μ-nmpen)]n (1) and [Ag(sac)(mpr)]2 (2) (sac=saccharinate; nmpen=N-methyl-1,3-propanediamine; mpr=2-methyl-1-pyrroline) have been synthesized and characterized by IR spectra, thermal (TG, DTG and DTA) analysis and single crystal X-ray diffraction techniques. Complexes crystallize in the monoclinic system with the space group C2/c and P21/c, respectively. In 1, Ag(I) ion exhibits a distorted tetrahedral geometry by tridentate μ3-bridging sac and μ2-bridging nmpen ligands. The sac ligand exhibits a new μ3-coordination mode by means of μ2-bridging O atom of sulfonyl group and N atom of imino group. Furthermore, complex 1 exhibits a two-dimensional polynuclear structure. In 2, the silver(I) ion is linearly coordinated by the N atoms of a sac and a mpr ligands, forming mononuclear species. The individual molecules are linked into dimers by Ag···Csac (η1) interactions between silver(I) ion and phenyl ring of the adjacent complex and these dimers are assembled into two-dimensional layered networks through weak Ag···Ag (3.507Å), SO···Ag (2.961Å) and π···π interactions. The most interesting structural features of complexes is the presence of obvious C–H···M hydrogen-bonding interactions between the Ag centers and H atoms of nmpen or mpr ligands.