Synthesis and crystal structure of trans-2,2′-(1,4-but-2-enediyldithio)-1,3-dithiazole and its Ag(I) complex with two-dimensional framework

A new ditopic thioether ligand, trans-2,2′-(1,4-but-2-enediyldithio)-1,3-dithiazole (L) and its self-assembly product with silver nitrate [AgL(NO3)]∞ (1) have been synthesized and structurally characterized by IR, 1H NMR, elemental analysis and single-crystal X-ray diffraction analysis. In the crystal structure of L, there is a symmetric center located at the midpoint of the 1,4-but-2-enediyl group with the two thiazole rings anti-parallel to each other. The L molecules are further linked through intermolecular C-H⋯N hydrogen bonds to form a 1D polymeric chain along the a axis. The crystal structure of complex 1 is a 2D network, in which the Ag(I) atom adopts a distorted tetrahedral geometry composed of two N and one S donors from three distinct ligands and one O donor from a nitrate anion. There exist weak Ag-Ag interactions in 1. The 2D grid networks are further connected to form an extended 3D structure through intermolecular C-H⋯O hydrogen bonds. The ligand L in 1 adopts two different coordination modes (i.e. N,N-bidentate and N,N,S,S-tetradentate modes) and two different conformations obviously varied to the free L, so as to suit for the coordination geometry of the metal ion.