Supramolecular Self-Assembly And Responsiveness Based On Organogold(?) And Organoplatinum(?)

Supramolecular chemistry also called "chemistry beyond molecule" is a kind of chemistry based on the non-covalent bond interactions which include hydrogen bonding interactions,?-? stacking interactions,host-guest interactions,aromatic donor-acceptor interactions and so on.Supramolecular assemblies usually have responsive to the heating,solvents,and others conditions,because of its constructed by non-covalent bond interactions.In this work,we use rod-coil monomer as the building block combined with hydrogen bonding interactions,metal-smetal interactions and other non-covalent bond interactions to construct supramolecular assembly and gels,and then explore the mechanistic and responsiveness of supramolecular assembly..In the first part,rod-coil alkynyl-gold(?)-isocyanide monomer has been successfully designed and synthesized,which represents a novel type of cooperative self-assembled system with the involvement of intermolecular Au(?)-Au(?)interactions.Detailed mechanistic studies illustrate that self-assembly of alkynyl-gold(?)-isocyanide monomer is co-driven by aurophilic Au(?)-Au(?)and hydrogen bonding interactions,leading to the formation of supramolecular fibers and entangled gels in non-polar solvents.Sol-gel transition of alkynyl-gold(?)-isocyanide monomer can be further achieved via the successive addition of AgOTf and Bu4NI.Hence,the current study provides a new avenue toward the development of organogold(?)-based materials.In the second part,we have successfully constructed a novel type of chromic system on the basis of highly emissive 6-phenyl-2,2'-bipyridine complexes.For the rod-coil monomer,it self-assembles in the apolar medium via the isodesmic mechanism,giving rise to the formation of supramolecular gels.Low-energy absorbance and NIR emission metal-metal-to-ligand charge transfer signals are absent in the monomeric state and emerge at the self-assembled state,which lays the basis for the solvatochromic phenomenon.Our study shows that minor structural variations on the rod-coil monomers exert crucial impacts on the gelation capability.Ionochromism phenomenon occurs for the rod-coil-rod monomer,by taking advantage of non-covalent ion-dipole complexation between Na+ cation and the flexible tetra(oxyethylene)spacer.Hence,the precise manipulation of Pt-Pt metal-metal and ?-stacking interactions provides an efficient avenue toward chromic materials with the tailored functionality.