Ligand Side Chain Structure Tuned Argentophilic Interaction And Supramolecular Chirality Of Ag~+-SR Coordination Polymers

Metal-metal interactions have in recent decades received extensive attention in the field of supramolecular chemistry due to their physical and chemical properties.Our laboratory has constructed Ag+-SR supramolecular coordination polymers facilitated by Ag+…Ag+interactions through the in situ reaction of thiol ligands and Ag+and developed their applications in supermolecular gels,recognition and sensing of chemical molecules.However,researches of the structure-property relationships remains to be explored.Therefore,rational design and synthese of Ag+-SR systems,as well as their applications are active subjects.Encouraged by the previous work of our group,a series of chiral thiol ligands were designed and synthesized based on the cysteine ethyl ester(CysOEt)in an attempt to tune the supramolecular chirality and Ag+…Ag+interactions of the Ag+-CysOEt coordination polymers of thiol ligands of different side chain structures,and to explore the structure-property relationships of the Ag+-SR coordination polymers.This dissertation consists of three chapters.Chapter 1:The origin and characterization of metal-metal interactions were briefly summarized.The formation,governing factors and research progresses of the Ag+-SR coordination polymers are discussed,with a focus on the chirality expression of the supramolecular polymers.Research objectives of this dissertation were finally presented.Chapter 2:We designed and synthesized N-(l-naphthoyl)and N-(2-naphthoyl)cystein ethyl esters(1-NCysOEt and 2-NCysOEt),together with a series of control compounds of N-benzoyl derivatives with one or two methhyl groups substituted on the phenyl ring to investigate the effect of side chain modification on supramolecular chiral expression of the Ag+-CysOEt coordination polymers.We found that the Ag+-1NCysOEt coordination polymers exhibit majority rules effect(MRE)characteristic of chiral amplication,while Ag+-2-NCysOEt polymers show the "Racemate Rules Effect(RRE)".Control experiments with coordination polymers of Ag+with N-benzoyl derivatives revealed that the difference in the substituations at ortho or meta position of methyl group is a key to regulate the chirality expression of the Ag+-1-/2-NCysOEt supramolecular coordination polymers.This study explores the structure-property relationships of supramolecular chirality expression,which brings new examples for the RRE in supramolecular chiral systems.Chapter 3:We designed and synthesized N-(2-hydroxybenzoyl)cysteine ethyl ester(2-OH-PhCysOEt)and N-(2-methoxybenzoyl)cysteine ethyl ester(2-OMePhCysOEt)with an intramolecular hydrogen bond in the former and Nbenzoylhomocysteine ethyl ester(Ph-HCysOEt)with a more flexible side chain to regulate the Ag+…Ag+interactions in their coordination polymers of Ag+,through the side chain hydrogen bonding and side chain flexibility.The study revealed the effect of the intramolecular hydrogen bonding in the ligand compound and inter-ligand hydrogen bonding,which provides new hints for rational construction of functional Ag+-CysOEt coordination polymers.In conclusion,we have developed various types of Ag+-CysOEt coordination polymers and regulated their supramolecular chirality expression and Ag+…Ag+interactions,through side chain structures.The work in this dissertation provides new guidances for the structure-property relationships of the Ag+-CysOEt systems and for the design of functional coordination polymers facilitated by Ag+…Ag+interactions.