共轭聚电解质-铂(Ⅱ)配合物超分子聚集体:相互作用依赖的光物理研究  

Interaction-dependent photophysical behavior of two-component ensembles arising from conjugated polyelectrolytes and platinum(Ⅱ)complexes of different supramolecular architectures

作　　者：陈启彦 钟亦琛 任詠华[1] Kevin Chan;Clive Yik-Sham Chung;Vivian Wing-Wah Yam(Institute of Molecular Functional Materials and Department of Chemistry,The University of Hong Kong,Hong Kong 999077,China)

机构地区：[1]香港大学化学系,分子功能材料研究所,中国香港999077

出　　处：《科学通报》2025年第7期929-943,共15页Chinese Science Bulletin

基　　金：中国香港特别行政区研究资助局一般研究基金(GRF)(HKU 17302723)资助。

摘　　要：一种具有中断π-共轭的阴离子共轭聚电解质(CPE),即带有二苯醚单元的聚(苯撑乙炔磺酸盐)(bPPE-SO_(3)^(-))诱导炔基铂(Ⅱ)配合物在缓冲液中通过静电、Pt…Pt和π-π堆积相互作用形成的双组分CPE-铂(Ⅱ)配合物聚集体.有趣的是,bPPE-SO_(3)^(-)铂(Ⅱ)配合物(1)双组分聚集体的相互作用、能量转移过程及其光物理性质与结构相似的CPE(PPE-SO_(3)^(-))-1聚集体相比,表现出显著差异.由于bPPE-SO_(3)^(-)具有较大的Forster半径、较高的三重态能量以及较大的HOMO-LUMO能隙,光诱导电荷转移(PCT)和Dexter三重态能量回传(TEBT)对铂(Ⅱ)配合物发射的猝灭效应被有效抑制,从而促进了高效FRET过程,进而引发三重态金属-金属到配体电荷转移(3MMLCT)发射.此外,bPPE-SO_(3)^(-)在1浓度增加时表现出多步发射光谱响应,这一结果归因于bPPESO_(3)^(-)的结构非共面性,其扭曲的-O-连接基削弱了分子内的疏水和π-π堆积相互作用,使其更容易受到微环境变化的扰动.Recent works have shown that cationic alkynylplatinum(Ⅱ)2,6-bis(benzimidazol-2′-yl)pyridine(bzimpy)complexes possess the capability of undergoing electrostatic assembly with anionic conjugated polyelectrolytes(CPEs)to form twocomponent supramolecular ensembles.However,previous studies on the FRET properties of CPEs were mainly focused on and restricted to rigid and extendedπ-conjugated polymers,while little discussions have been made on those with flexible linkers or interruptedπ-conjugation.Moreover,the mechanism for the reciprocal interactions between the CPE and platinum(Ⅱ)complexes in the formation of the ensemble is essentially less explored.Therefore,in order to have a more indepth understanding and to provide further insights into these processes,a CPE with interruptedπ-conjugation,poly(phenylene ethynylene sulfonate)with a diphenyl ether unit(bPPE-SO_(3)^(-)),has been employed to induce the formation of supramolecular aggregates of alkynylplatinum(Ⅱ)bzimpy complexes in aqueous buffer solution.The formation of the twocomponent CPE-platinum(Ⅱ)complex ensembles via electrostatic,Pt∙∙∙Pt andπ-πstacking interactions has been investigated by UV-vis absorption,steady-state emission,resonance light scattering,and time-resolved emission experiments.Interestingly,the reciprocal interactions,energy transfer processes and the resultant photophysical properties of the two-component ensemble comprising bPPE-SO_(3)^(-)and[Pt(bzimpy-Et){C≡CC_(6)H_(4)(CH_(2)NMe_(3)-4)}]Cl_(2)(1)have been found to be distinctively different when compared to those formed by 1 with a structurally similar CPE,PPE-SO_(3)^(-).The conformational flexibility and geometrical features imparted by the-O-linker of bPPE-SO_(3)^(-)has empowered it with the capability in forming strong bPPE-SO_(3)^(-)-1 aggregates,as evidenced by the large Stern-Volmer constants in the presence of 1 at low concentrations.Due to the combination of a relatively large Fӧrster radius,high triplet state energy of bPPE-SO_(3)^(-)as well as large HOMO-L

关 键 词：超分子化学 能量转移 共轭聚电解质 金属-金属相互作用 铂 

分 类 号：O641.4[理学—物理化学]