Newman Ben, Chen Lifen, Henderson Luke C, Doeven Egan H, Francis Paul S, Hayne David J
School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, Geelong, VIC, Australia.
Institute for Frontier Materials, Deakin University, Geelong, VIC, Australia.
Front Chem. 2020 Oct 15;8:583631. doi: 10.3389/fchem.2020.583631. eCollection 2020.
Four cationic heteroleptic iridium(III) complexes containing a 2,2'-bipyridine (bpy) ligand with one or two tetraethylene glycol (TEG) groups attached in the 4 or 4,4' positions were synthesized to create new water-soluble electrogenerated chemiluminescence (ECL) luminophores bearing a convenient point of attachment for the development of ECL-labels. The novel TEG-derivatized bipyridines were incorporated into [Ir(CN)(R-bpy-R')]Cl complexes, where CN = 2-phenylpyridine anion (ppy) or 2-phenylbenzo[d]thiazole anion (bt), through reaction with commercially available ([Ir(CN)(μ-Cl)] dimers. The novel [Ir(CN)(Me-bpy-TEG)]Cl and [Ir(CN)(TEG-bpy-TEG)]Cl complexes in aqueous solution largely retained the redox potentials and emission spectra of the parent [Ir(CN)(Me-bpy-Me)]PF (where Me-bpy-Me = 4,4'methyl-2,2'-bipyridine) luminophores in acetonitrile, and exhibited ECL intensities similar to those of [Ru(bpy)] and the analogous [Ir(CN)(pt-TEG]Cl complexes (where pt-TEG = 1-(TEG)-4-(2-pyridyl)-1,2,3-triazole). These complexes can be readily adapted for bioconjugation and considering the spectral distributions of [Ir(ppy)(Me-bpy-TEG)] and [Ir(ppy)(pt-TEG)], show a viable strategy to create ECL-labels with different emission colors from the same commercial [Ir(ppy)(μ-Cl)] precursor.
合成了四种含2,2'-联吡啶（bpy）配体的阳离子杂配铱（III）配合物，该配体在4或4,4'位连接有一个或两个四甘醇（TEG）基团，以制备新型水溶性电致化学发光（ECL）发光体，其带有便于ECL标记物开发的连接位点。通过与市售的([Ir(CN)(μ-Cl)]二聚体反应，将新型TEG衍生的联吡啶引入[Ir(CN)(R-bpy-R')]Cl配合物中，其中CN = 2-苯基吡啶阴离子（ppy）或2-苯基苯并[d]噻唑阴离子（bt）。新型[Ir(CN)(Me-bpy-TEG)]Cl和[Ir(CN)(TEG-bpy-TEG)]Cl配合物在水溶液中很大程度上保留了母体[Ir(CN)(Me-bpy-Me)]PF（其中Me-bpy-Me = 4,4'-甲基-2,2'-联吡啶）发光体在乙腈中的氧化还原电位和发射光谱，并且表现出与[Ru(bpy)]以及类似的[Ir(CN)(pt-TEG]Cl配合物（其中pt-TEG = 1-(TEG)-4-(2-吡啶基)-1,2,3-三唑）相似的ECL强度。这些配合物易于进行生物共轭，并且考虑到[Ir(ppy)(Me-bpy-TEG)]和[Ir(ppy)(pt-TEG)]的光谱分布，展示了一种从相同的市售[Ir(ppy)(μ-Cl)]前体创建具有不同发射颜色的ECL标记物的可行策略。
