Platinum(?)-Based Metallosupromolecules:Synthesis,Self-Assembly And Photophysical Properties

Square-planar platinum???complexes have d⁸electronic configuration and show abundant spectroscopic properties due to the splitting of orbital energy levels.The platinum???based complexes form tightly aggregated structures under the Pt???Pt and?-?stacking interactions and thus show intensive luminescence properties.Among platinum???coordination complexes,N^N^N-type polypyridine platinum???complexes are widely used in drug delivery,fluorescent sensors,luminescence switch materials and catalytic separation field,owing to their excellent luminescence and self-assembly behaviors.In this thesis,a series of N^N^N-typed polypyridine platinum???complexes were prepared firstly.Furthermore,their self-assembly behaviors and photophysical properties in aqueous solution and selective solvent were investigated in detail based on electrostatic interactions.1.Cationic platinum???complex 1 which has two hydrophilic chains,were firstly synthesized.Rod-like and soft belt-like amphiphilic metallosupromolecules formed by self-assembling complex 1 with anionic surfactants sodium deoxycholate?DCA?and sodium taurodeoxycholate sodium salt?TCA?respectively,via electrostatic interaction,Pt???Pt and?-?stacking interactions in aqueous solution.In this process,the intensity of the MMLCT absorption peak and the ³MMLCT emission peak were significantly enhanced,indicating obvious luminescence enhancement.What's more,the intensity of the luminescence quenched back to the original level after?-CD was adding to the system,probably because of the host-guest recognition between DCA or TCA and?-CD,and disassembling of the aggregates.This reversible system could be used as molecular logical response.2.Two kinds of polypyridine Pt???complexes hybrid materials S_I-2 and S_?-2,with tris?dodecyl?benzamide groups of sulfonate groups at each end were firstly designed and synthesized.S_I-2 and S_?-2 complexes self-assembled into rod-like and wormlike aggregates in methanol/chloroform mixed solvent with low methanol content respectively.As the methanol content increasing,the rod-like structure and worm-like structure elongated,shrunk,and interspersed with each other,and finally self-assembled into a network-like layered structure,which accompanied with luminous enhancement.This process has a strong luminous enhancement phenomenon.3.Irregular wormlike structured aggregate was constructed by self-assembling complex 1 with anionic poly?lipoic acid??PLA-1?,via electrostatic interaction,Pt???Pt and?-?stacking interactions in aqueous solution.Compared with the complex 1,the emissive intensity of the resulting aggregate is greatly enhanced.The luminescence also quenched back to the original level after sodium borohydride?NaBH₄?or glutathione?GSH?was adding to the system,because of disassembling of the aggregates.This method can also be used as reversible regulation of luminescence.