Design And Synthesis Of Novel Triphenylamine Derivatives Founctionalized POSS-Based Fluorescent Porous Polymers

Organic fluorescent porous polymer possesses the twin superiorities of porosity and fluorescence,has the potential to be employed as multifunctional material in detection,adsorption,drug delivery,bio-imaging,heterogeneous catalysis,energy transfer and other fields.Although some organic fluorescent porous polymers have been developed,there still are some the challenges of design,synthesis,stability,porosity and fluorescence.Polyhedral oligomeric silsesquioxane(POSS)is an unique organosilicon species,offering many advantages of light weight,low skeleton density,high stability,resistance to acid,resistance to oxidation,low permittivity,good biocompatibility and so on,is ideal building block for porous polymer.In the cross-linked networks of fluorescent porous polymers,POSS could prevent the emission quenching derived from the aggregation of fluorescent units,enhance the emission signal of polymer;meanwhile,their three-dimensional and rigid structure prefers to produce stable porosity in cross-linked network.However,conventional organic fluorophore functionalized POSS polymer generally displayed short emission wavelength,low quantum yield,small Stokes shift and so on,which seriously restricted their application in many fields.Therefore,triphenylamine derivatives with long emission wavelength,large Stokes shift,high quantum yield,and rigid structure are preferable to produce excellent fluorescence and porosity when they link with POSS to generate cross-linked network.These processes develop a avenue for the design and preparation of functional porous polymer,and further provide a new method for the developing of triphenylamine(TPA)derivatives.Chapter 1.We introduce the progress of organic fluorescence polymer,outline the properties of POSS and TPA derivatives.Finally,we highlight the scientific significance and content of this thesis.Chapter 2.An aggregation-induced emission(AIE)active TPA derivative(TPA-TCMP)with large Stokes shift,high quantum yield,large ?-conjugated system and rigid structure is designed and synthesized.Employing OVS and TPA-TCMP as building blocks,polymer THPP-1 with high stability,preferable fluorescence and porosity is synthesized based on Fridel-Crafts reaction.According to their good fluorescence and porosity,THPP-1 is applied to the detection and adsorption of Ru3+.Chapter 3.Two species of near infrared and AIE behavioral compounds(TPA-B-DCM and TPA-N-DCM)deriving from TPA fluorogen are synthesized.These molecules display larger Stokes shift of 200 nm,high solid quantum yield of 19%.Furthermore,the AIE fluorescence mechanism of TPA-B-DCM and TPA-N-DCM is determined to be the restricted intramolecular rotation and twisted molecular plane deriving from steric effect.Employing TPA-B-DCM/TPA-N-DCM and OVS as building blocks,polymer THPP-2 and THPP-3 with hyper-cross-linked network,large specific surface area and preferable fluorescence are prepared.The large ?-conjugation and high porous volume in cross-linked network ensure THPP-2 and THPP-3 to absorb CO2efficiently with the high adsorption capacity of 5.45%and 66%,respectively.Chapter 4.TPA derivatives TPA-O-DCM and TPA-S-DCM with aggregation-caused quenching feature are designed and synthesized.Near infrared fluorescence polymers HPP-O and HPP-S are synthesized from OVS and TPA-O-DCM/TPA-S-DCM by Friedel-Crafts reaction,exhibit large Stokes shift,high specific surface areas and microporous content.The high content of heteroatoms and micropores in the cross-linked network could efficiently absorb CO2 and Au3+.Interestingly,the adsorption of Au3+could quench the fluorescence emission of polymers,and realize the concurrent detection and adsorption of noble metal ions Au3+.In addition,theprocessability of hyper-cross linked polymer is still a challenge,using their dispersibility and good compatibility with polyacrylonitrile to fabricate red emission nanofibrous membrane by eletrospinning method.Chapter 5.Near infrared fluorescent porous polymer TPAIE-1 is synthesized though Friedel-Craft reaction employing TPA-DCM and OVS as building blocks.TPAIE-1 is disordered and amporphous hyper-cross linked networks,possesses large Stokes shift and high thermal stability.To deeply understand the performance of fluorescence unit in cross-linked network,the fluorescent fragment is simplified to be M-TPA-DCM.M-TPA-DM exhibits AIE feature and enhanced emission,which is completely different from monomer TPA-DCM.Therefore,producing cross-linked network is accompanied with the generation of in situ enhanced fluorescence and AIE fragments.