Self-assembly of thiolate-protected silver coordination polymers regulated by POMs

Abstract

Two polyoxometalate (POM)-based thiolate-protected silver coordination polymers were obtained using different Lindquist-type POM precursors under the same conditions. [Ag₁₀(S^tBu)₆(CH₃CN)₈(Mo₆O₁₉)₂·2CH₃CN]_n (abbreviated as Ag₁₀-Mo₆) was observed to feature chain-like structures containing Ag₁₀ clusters linked by [Mo₆O₁₉]²⁻ anions through Ag–O bonds and to exhibit unprecedented green photoluminescence at room temperature. Interestingly, [Ag₁₈(S^tBu)₁₂(CH₃CN)₅(Mo₆O₁₉)₂·Mo₆O₁₉·2CH₃CN]_n (abbreviated as Ag₁₈-Mo₆) was found to contain 20-membered cycle-Ag₁₀S₁₀ each with a diameter of approximately 11.382 Å and constructed from alternating silver and sulfur atoms and interconnected into an elegant Ag–S sheet by interstitial the Ag₃S^tBu and AgCH₃CN motifs, and to also contain [Mo₆O₁₉]²⁻ counter ions filling in the spaces made by the cycle-Ag₁₀S₁₀ and strengthening the structure by forming Ag–O bonds. Such a stacking structure for thiolate-protected silver compounds has not been previously reported.