Construction of silver–organic framework with silver rods of repeated Ag-triangle units: Synthesis, structure, and properties

A new thick silver rod incorporating repeated Ag3 units sustained by 1,3,5-benzenetricarboxylic acid (1,3,5-H3BTC) and Ag⋯Ag interactions, {[Ag3(BTC)(pyz)]·(H2O)}n (1) (pyz = pyrazine), has been synthesized and structurally characterized. Compound 1 displays a three-dimensional coordination framework with infinite 1D Ag rod, and adjacent silver rods bridged by the 1,3,5-H3BTC and pyz ligand. Argentophilicity plays an important role in determining the infinite silver(I) rods. Complex 1 exhibits photoluminescence maximized at 542 nm upon 363 nm excitation at room temperature, which may be mainly assigned to ligand-to-metal charge transfer (LMCT) perturbed by Ag⋯Ag interactions. Temperature dependent luminescence spectra from 298 to 77 K have been studied. Upon decreasing the temperature from 298 to 77 K, the emission bands grow in intensity. In addition, the thermogravimetric analysis and powder X-ray diffraction (PXRD) of complex 1 have also been investigated.