Various Silver Phosphinate Inorganic Architectures\nin Three-Dimensional Frameworks with Argentophilic Interactions

Abstract

Three\nsilver compounds\nwith the formulas: [Ag₂(HL¹)] (<b>1</b>), [Ag₁₀(L²)₂(H₂O)_1.25] (<b>2</b>), and [Ag₅(L³)]·1.5H₂O (<b>3</b>) were obtained\nby self-assembly of silver nitrate with 4,4′-phosphinicobis-dibenzoic\nacid (H₃L¹), 4,4′-phosphinicobis-diisophthalic\nacid (H₅L²), and 2,2′-phosphinicobis-diisophthalic\nacid (H₅L³) under hydrothermal conditions. The\nstructures of these compounds were confirmed by various characterization\nmethods. Both <b>1</b> and <b>2</b> crystallize in <i>P</i>2₁/n space group and present three-dimensional\n(3D) frameworks, which contain a sliver phosphinate inorganic chain\nor sheet formed by Ag–Ag interactions. Meanwhile, compound <b>3</b> is in <i>C</i>2/<i>c</i> space group\nand also displays a 3D silver-organic architecture. The open-framework\ncontains narrow channels along the <i>c</i>-axis with an\nopening of 0.26 nm × 0.32 nm. The intriguing feature of the structure\nis emergence of a 3D inorganic skeleton in <b>3</b>, which struts\nthe whole framework. The 3D inorganic skeleton is generated from a\nsilver phosphinite chain connected by strong Ag–Ag interactions.\nAt room temperature, the compounds exhibit blue photoluminescence.