Transformation of dense AgI into a silver-rich framework iodide using thiophenol as mineralizer

A new three-dimensional framework iodide, (DabcoH)₂[(Dabco)₂Ag₁₄I₁₆] (1), was solvothermal synthesized by transformation of dense AgI using p-methylthiophenol as mineralizer, and characterized by elemental analysis, single-crystal and powder X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry analysis, UV–vis diffuse reflectance spectroscopy and fluorescence spectroscopy. Compound 1 crystallizes in the trigonal space group R-3c, a=13.4452(2) Å, c=63.725(2) Å, V=9976.5(4) ų, Z=6. It features a 3D silver-rich [(Dabco)₂Ag₁₄I₁₆]²⁻ anionic framework built up from corner-sharing of hybrid [(Dabco)₂Ag₁₄I₁₉]⁵⁻ clusters, with protonated DabcoH⁺ as counterions residing in the channels. UV–vis reflectance spectroscopy reveals the band gap of 1 is 3.3 eV. Compound 1 exhibits a strong photoluminescent emission band at 567 nm upon excitation at 489 nm. - Graphical abstract: A new 3-D iodoargentate was synthesized by transformation of dense AgI in I⁻-deficient system using thiophenol as mineralizer. - Highlights: • We have developed a new method to synthesize iodide using thiophenol as mineralizer. • A new 3D iodide, (DabcoH)₂[(Dabco)₂Ag₁₄I₁₆], was synthesized by transformation of dense AgI under solvothermal condition. • The compound features a 3D Ag–I framework with highest Ag/I ratio. • Compound 1 is a semiconductor with the band gap of 3.3 eV. • Compound 1 exhibits a strong photoluminescent emission band at 567 nm upon excitation at 489 nm