Costa Ana L, Gomes Ana C, Pillinger Martyn, Gonçalves Isabel S, de Melo J Sérgio Seixas
Coimbra Chemistry Centre, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra (Portugal).
Department of Chemistry, CICECO - Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal).
Chemistry. 2015 Aug 17;21(34):12069-78. doi: 10.1002/chem.201501344. Epub 2015 Jul 17.
Zn-Al layered double hydroxides (LDHs) containing solely indigo carmine (IC) or 1-hexanesulfonate (HS) anions, or a mixture of the two with different HS/IC molar ratios, were prepared by the direct synthesis method and characterized by various techniques. Hydrotalcite-type phases were obtained with basal spacings of 17.6 Å for the LDH intercalated by IC (IC-LDH) and 18.2-18.3 Å for the other materials containing HS. From the basal spacing for IC-LDH and UV/Vis spectroscopic data, it is proposed that the dye molecules assemble within the interlayer galleries to form a J-type stacking arrangement. A comprehensive electronic spectral and photophysical study was undertaken for IC in solution and all materials, aiming to obtain a detailed characterization of the host-guest and guest-guest interactions. In solution (the solvent surrounded "isolated" molecule), IC presents a fast excited state proton transfer with rate constants of ∼1.2-1.4×10(11) s(-1) , which is linked to the very efficient radiationless deactivation channel. In the solid state it is shown that incorporation of IC within the LDH decreases the level of aggregation, and that further addition of HS induces the appearance of isolated IC units within the LDH galleries. The indigo carmine-based nanocomposites reported constitute a step forward in the design of hybrid materials with tunable properties.
通过直接合成法制备了仅含有靛蓝胭脂红（IC）或1-己烷磺酸盐（HS）阴离子，或两者以不同HS/IC摩尔比混合的锌铝层状双氢氧化物（LDH），并采用多种技术对其进行了表征。对于由IC插层的LDH（IC-LDH），获得了水滑石型相，其层间距为17.6 Å，对于其他含HS的材料，层间距为18.2 - 18.3 Å。根据IC-LDH的层间距和紫外/可见光谱数据，提出染料分子在层间通道内组装形成J型堆积排列。对溶液中的IC和所有材料进行了全面的电子光谱和光物理研究，旨在详细表征主客体和客体-客体相互作用。在溶液中（溶剂包围“孤立”分子），IC呈现快速的激发态质子转移，速率常数约为1.2 - 1.4×10(11) s(-1)，这与非常有效的无辐射失活通道有关。在固态中表明，将IC掺入LDH中会降低聚集水平，并且进一步添加HS会导致在LDH通道内出现孤立的IC单元。所报道的基于靛蓝胭脂红的纳米复合材料在具有可调性质的杂化材料设计方面向前迈进了一步。
