Synthesis,Structures And Properities Of Atom-precise Carboxyl Ligands Incorporated Silver Chalcogenide Nanoclusters

Silver??? chalcogenide clusters have attracted wide interest in recent years owing to their novel structures,excellent optical properties,and potential applications in various fileds,such as bioimaging,drug transportation,chemical sensing and catalysis.To design and synthesize new functional silvers?I?chalcogenide clusters,the choice of ligands is important.The functional groups of ligands make the silvers?I?clusters exhibit fascinating properties.In previous studies,thiolate,alkynyl or organophosphorus ligands were used to synthesize silver??? clusters.Compared with the above ligands,the coordination ability of the carboxylic ligands is a bit weaker,so this kind of ligands is less used in the synthesis of silver??? clusters.The carboxylic ligands also can make the synthesized silver??? clusters have unique properties.Therefore,a series of carboxylic ligands were selected to synthesize six atom-precise silver??? clusters with good properties.The content of this paper includes three parts as follows:1.Three carboxylic ligands with functional naphthalene groups were synthesized,and then were self-assembled with silver salts to obtain three atomic-precise silver??? clusters,which exhibited blue luminescence:[?CO₃?@Ag₂₀?S^tBu?₁₀(C₁₂H₆O₂N C₂H₄COO)₄?NO₃?₄?DMAc?₄]?1?,[?CO₃?@Ag₂₀?S^tBu?₁₀(C₁₂H₆O₂NC₈H₈COO)₄?NO₃?₄?CH₃CN?₄]?2?,[?CO₃?@Ag₂₀?S^tBu?₁₀(C₁₂H₆O₂NC₂H₃OHCOO)₆?NO₃?₂]?3?.The three clusters have the same drum-like metal core Ag₂₀S₁₀,but the ligands shell are different not only in ligands types but also in ligands numbers.The fluorescence emission spectra of the three clusters are similar to the corresponding ligands,which originate from ligand to ligand charge transition?LLCT?.The aggregation induced emission?AIE?of 1 is also investigated.2.A water-soluble silver??? cluster,[Ag₃₇S₄?C₂H₂S₂?COOH?₂?₁₂?S^tBu?₄]⁺?4?,has been synthesized by using a dicarboxylic ligands.The fluorescence emission spectrum of 4 varies in color in response to a temperature change,which is orange-red at room temperature and yellow at lower temperature.3.The chirality of silver clusters can be induced by the introduction of chiral carboxyl ligands.A pair of atom-precise chiral clusters,[S^2-@Ag₁₄?D-pen?₁₂]?5?and[S^2-@Ag₁₄?L-pen?₁₂]?6?,induced by D/L-penicillamine have been obtained.The coordination of the penicillamine ligands successfully induced the formation of chiral Ag₁₄ core.The CD spectra of 5 and 6 display an excellent mirror image relationship.Moreover,the proton conductivity of 5 was also explored due to the existence of the amino groups and carboxylate groups from ligands,which are beneficial to construct H-bond network for proton transfer.