Synthesis And Structure Of High-Nuclearity Silver Clusters Constructed With Phosphonates

This dissertation focuses on the synthesis of novel high-nuclearity silver clusters and heterometallic clusters using phosphonates and RC?CAg or RSAg precursors.The synthesis conditions and rules of these clusters are studied.The impaction of the ancillary ligands and template ion-pairs on the structure of the silver clusters are explored,as well as the relationship between the structure and performance of the new materials formed.We synthesized a series of novel high-nuclearity silver clusters via conventional reaction methods.The crystal structures were characterized by elemental analysis and Single crystal X-ray diffraction.The main research contents and results of this paper are as follows:(1)The ancillary ligand hfac-,template ions,and tert-butyl phosphonate ligands were employed to construct eight new silver-ethynide clusters.Single crystal structure analysis revealed that complexes 2a–2h are functionalized by hexafluoroacetylacetones,which serve as the terminal protective ligands.Different kinds of templates are located in the center of the compounds 2c–2h,respectively.While in compounds 2g and 2h,the tert-butyl phosphonate ligands function as the bridging ligands link two small silver(I)clusters together to form an enlarged cluster.Therefore,the introduction of hexafluoroacetylacetone and tert-butyl phosphonates greatly increase the structural diversity of silver-ethynide clusters.[Ag10(tBuC?C)7(hfac)3(CH3OH)](2a)[Ag12(tBuC?C)8(hfac)4(CH3OH)2](2b)[Cl@Ag16(tBuC?C)11(hfac)3(CF3COO)](2c)[Ag@Ag16(tBuC?C)12(hfac)2(CF3COO)3](2d)[Mo O4@Ag19(tBuC?C)12(hfac)2(CF3COO)3](2e)[V2O7@Ag24(tBuC?C)14(hfac)6](2f){[NO3@Ag22(tBuC?C)14(tBuPO3)2(hfac)(CF3COO)(OH)]·CH3CN}(2g)[V2O7@Ag40(tBuC?C)22(tBuPO3)4(hfac)4(CF3COO)2(H2O)2](2h)(2)The reaction of tBuSAg with tBuPO3H2 obtained one silver thiolate cluster of [(NO3)@Ag20(tBuS)10(tBuPO3H)6(tBuPO3H2)4(NO3)2]?(OH)?4CH3OH?6H2O,in which phosphonate ligands and thiolates distributed around the skeleton of NO3@Ag20 and coordinated with the silver ions to stabilize the silver cluster.The reaction of nBuPO3H2 with R1SAg(R1 = 3-Methyl-2-butane),tBuSAg,respectively,resulted in six novel silver thiolate clusters of 3b–3g with a core-shell structure,of which compounds 3d–3g feature a three-shell arrangement.During the synthesis of silver thiolate clusters,nBuPO3H2 act as structure-directing agents for the first time,and constitute the silver cluster framework or cover its surface,leading to the formation of silver thiolate clusters in the core-shell structure.[(NO3)@Ag20(tBuS)10(tBuPO3H)6(tBuPO3H2)4(NO3)2]?(OH)?4CH3OH?6H2O(3a){Ag3S6@Ag42(R1S)30(nBuPO3)(nBuPO3H)}(R1 = 3-Methyl-2-butane)(3b){[Ag@Ag17@(nBuPO3)9@Ag39(tBuS)26(NO3)3]·10NO3·23CH3OH}n(3c){[S@Ag12@(nBuPO3)9@Ag36(tBuS)23(CH3O)2(NO3)3]·2CH3OH}n(3d){[S@Ag11@(nBuPO3)7(Mo O4)2@Ag40(tBuS)27(CH3O)2(NO3)2(H2O)2]·8CH3OH?1.5H2O}n(3e)[CH3OH2]6{Mo O4@Ag12@(nBuPO3)8S6@Ag36(tBuS)24}(3f)[CH3OH2]6{VO4@Ag12@(nBuPO3)8S6@Ag36(tBuS)24}(3g)(3)Phosphonate ligands(tBuPO3H2 or nBuPO3H2)were introduced into the coexistent system of tBuC?CAg and t BuSAg precursors,and then four novel silver sulfide-ethynide-thiolate clusters with core-shell structure were isolated.Single crystal X-ray diffraction analysis showed that compounds 4a–4d all have a silver sulfide cluster as the core,and the silver(I)aggregates tBuC?C?Ag3,tBuC?C?Ag4 and 2tBuC?C?Ag7 are bridged by thiolate ligands peripheral to engender respective silver(I)ethynide-thiolate clusters function as integral shell components,which are supported by phosphonate ligands.The phosphonate ligands serve as a structure-directing agent and enter the interior of the silver cluster framework or cover the surface of the silver shell to guide the synthesis of the silver cluster and the stabilizing of its structure.{S@Ag12S6@Ag36(tBuC?C)12(tBuS)12(nBuPO3)2(nBuPO3H)6}(4a){[S@Ag12S6@Ag36(tBuC?C)12(tBuS)12(tBuPO3)8][S@Ag16(tBuS)8(CH3OH)2(H2O)4]}? 5CH3OH(4b){[(Ag3S3)S3]@Ag42(tBuC?C)12(tBuS)18(nBuPO3)(nBuPO3H)(NO3)4(CH3OH)2(H2O)2}? 4[H3O](4c){Ag3S3@Ag30(tBuC?C)6(tBuS)12(tBuPO3)(tBuPO3H)(hfac)6(H2O)2}(4d)(4)The tert-butylphosphonate ligand was employed to react with Bi and Sn precursors to obtain Bi-O and Sn-O clusters functionalized by phosphonate ligand,which combined with tBuC?CAg forming three novel heterometallic clusters of 5a–5c.The formation of the heterometallic clusters is due to the fact that the phosphonate ligands can connect two or three small metal cluster units together function as bridging ligands during the self-assembly process of the metal clusters.Complexes 5b and 5c are sandwich structures in which three metal cluster units are sequentially connected.The method for synthesizing the heterometallic clusters has important guiding significance for the introduction of more metal ion sources into the silver cluster synthesis system later.{[Ag8(tBuC?C)4Bi9O6(tBuPO3)9(tBuPO3H)(CH3OH)2(H2O)2]?2CH3OH?4H2O}(5a){[Cl@Ag15(tBuC?C)8(hfac)]2[Bi6O4(OH)4(tBuPO3)6(hfac)2(CF3COO)2](CH3OH)2(H2O)2}?6CH3OH?4H2O(5b){[Cl@Ag12(tBuC?C)6][(nBuSn)3(?3-O)(tBuPO3)3(OMe)(OH)2]2}?2(CH3OH)?(H2O)?(OH)(5c)...