Burrows Hugh D, Costa Telma, Ramos M Luisa, Valente Artur J M, Stewart Beverly, Justino Licinia L G, Almeida Aline I A, Catarina Nathanny Lessa, Mallavia Ricardo, Knaapila Matti
Centro de Química, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
Instituto de Biología Molecular y Celular, Universidad Miguel Hernandez de Elche, Avda. de la Universidad s/n, 03202 Elche, Spain.
Phys Chem Chem Phys. 2016 Jun 22;18(25):16629-40. doi: 10.1039/c5cp07085f.
We have studied the interaction of 8-hydroxyquinoline-5-sulfonate (8-HQS) with the metal ions Al(iii) and Zn(ii) in aqueous solution in the presence of tetraalkylammonium surfactants using UV/vis absorption, fluorescence, NMR spectroscopy and electrical conductivity measurements, complemented by DFT calculations and molecular dynamics (MD) simulations. Under appropriate conditions, complexes between 8-HQS and metal ions form rapidly, and have similar electronic, spectroscopic and photophysical properties to the corresponding metal quinolates, such as Alq3. These interact with the cationic surfactants, leading to marked increases in fluorescence intensity. However, significant differences are seen in the behavior of the two metal ions. With aluminium, a stable Al(8-QS)3 anion is formed, and interacts, predominantly through electrostatic interactions, with the surfactant, without disrupting the metal ion coordination sphere. In contrast, with Zn(ii), there is a competition between the metal ion and surfactants in the interaction with 8-HQS, although the Zn(8-QS)2(H2O)2 species is stable at appropriate pH and surfactant concentration. The studies are extended to systems with the conjugated polyelectrolyte (CPE) poly-(9,9-bis(6-N,N,N-trimethylammonium)hexyl)-fluorene-phenylene bromide (HTMA-PFP), which has a similar alkylammonium chain to the surfactants. Mixing metal salt, 8-HQS and HTMA-PFP in the presence of a nonionic surfactant leads to the formation of a metal complex/CPE supramolecular assembly between the conjugated polyelectrolyte and the metal/8-HQS complex, as demonstrated by electronic energy transfer. The potential of these systems in sensing, light harvesting, and electron injection/transport layers in organic semiconductor devices is discussed.
我们使用紫外/可见吸收光谱、荧光光谱、核磁共振光谱和电导率测量方法，并辅以密度泛函理论（DFT）计算和分子动力学（MD）模拟，研究了在四烷基铵表面活性剂存在下，8-羟基喹啉-5-磺酸盐（8-HQS）与金属离子铝（Ⅲ）和锌（Ⅱ）在水溶液中的相互作用。在适当条件下，8-HQS与金属离子之间能迅速形成配合物，其电子、光谱和光物理性质与相应的金属喹啉盐（如Alq3）相似。这些配合物与阳离子表面活性剂相互作用，导致荧光强度显著增加。然而，两种金属离子的行为存在显著差异。对于铝，会形成稳定的Al(8-QS)3阴离子，它主要通过静电相互作用与表面活性剂相互作用，而不会破坏金属离子的配位球。相比之下，对于锌（Ⅱ），在与8-HQS的相互作用中，金属离子和表面活性剂之间存在竞争，尽管Zn(8-QS)2(H2O)2物种在适当的pH值和表面活性剂浓度下是稳定的。研究扩展到了含有共轭聚电解质（CPE）聚（9,9-双（6-N,N,N-三甲基铵）己基）-芴-亚苯基溴化物（HTMA-PFP）的体系，该聚电解质具有与表面活性剂相似的烷基铵链。在非离子表面活性剂存在下，将金属盐、8-HQS和HTMA-PFP混合，会导致共轭聚电解质与金属/8-HQS配合物之间形成金属配合物/CPE超分子组装体，这通过电子能量转移得以证明。讨论了这些体系在传感、光捕获以及有机半导体器件的电子注入/传输层方面的潜力。
