Template-Free Synthesis of Two New Luminescent One-Dimensional High-Nuclearity Silver Polyclusters

Twonew neutral high-nuclearity silver nanopolyclusterswith luminescence properties were synthesized by using Ph2PO2H and characterized. Ph(2)PO(2)Hwas coordinated to Ag centers with some new and rare coordinationmodes. The use of different ratios of the diphenylphosphinate ligandto metal with the same conditions led to the formation of two polyclusterswith different sizes and structures. The metallophilic properties, spherical configuration,and flexiblecoordination of silver ions make them prone to create various coordinationmodes and structural features. Therefore, with the increase of thecomplexities of self-assembly, the effect of various synthetic conditionsin the final structure of silver compounds becomes diverse and attractive.In this study, two new silver polyclusters, 16- and 21-nuclearity,protected by multiple ligands including alkynyl, trifluoroacetate,and diphenylphosphinate, were synthesized and characterized by single-crystalX-ray diffraction, powder X-ray diffraction, and Fourier transforminfrared (FTIR) spectroscopy. The optical properties and thermal stabilityof the polyclusters were studied by solid-state ultraviolet-visible(UV-vis) absorption and solid UV-vis diffuse reflectancespectra and gravimetric analysis, respectively. The formation of thetwo polyclusters can be fine-controlled by simply adjusting the stoichiometricratio of diphenylphosphinate ligands to silver precursors under thesame synthetic condition, leading to the different coordination modesbetween ligands and Ag centers. This work shows a facile and template-freemethod to synthesize and control the silver polycluster assembly,encouraging further development of new polyclusters with the potentialfor various applications.