Department of Applied Chemistry, National Chi Nan University, Nantou 545, Taiwan.
Dalton Trans. 2019 Jan 15;48(3):1095-1107. doi: 10.1039/c8dt04170a.
Compound [Cu(NI-mbpy-44)2(NO3)2]·4H2O (1, NI-mbpy-44 = N-(pyridin-4-ylmethyl)-4-(pyridin-4-yl)-1,8-naphthalimide) adopting a two-dimensional (2D) periodical rhombus (4,4) grid has been synthesized. This grid doubly interweaves in a parallel fashion to result in overall 2D + 2D → 2D networks with approximately 14% sufficient free volumes in which lattice H2O molecules reside. Dye removal studies show that 1 selectively adsorbs anionic methyl orange (MO) and acid orange 7 (AO7) over cationic methylene blue (MB) and malachite green (MG) from aqueous solutions containing single or mixed dyes in darkness at room temperature. The experimental isotherm data were analyzed using linear Langmuir and Freundlich isotherm equations; the results indicated that the Langmuir model showed a better fit for the adsorption of MO and AO7 over 1, with high dark adsorption capacities of 810 and 370 mg g-1, respectively, although there could also be other associated mechanisms. The dark adsorption kinetics of MO and AO7 over 1 obeyed the pseudo-second-order kinetic model. Electrostatic attraction appears to be the dominating mechanism for adsorptive removal of MO and AO7 by 1, whereas π-π stacking (MO and AO7) and hydrogen-bonding interactions (AO7) could also be responsible. Exploration of the adsorption performance of MO and AO7, including studying the kinetics in daylight, shows similar results to those obtained in darkness, indicating the negligible influence of daylight on the dye removal. Nevertheless, 1 could liberate NI-mbpy-44 and Cu(ii) into water throughout the entire adsorption experiment, which could be a potential environmental hazard, this could cause secondary pollution and mean that 1 is impractical for use as an adsorbent candidate.
采用二维（2D）周期菱形（4,4）网格合成了化合物 [Cu(NI-mbpy-44)2(NO3)2]·4H2O（1，NI-mbpy-44 = N-(吡啶-4-基甲基)-4-(吡啶-4-基)-1,8-萘酰亚胺）。该网格以平行方式双重交织，导致总体上具有 2D + 2D → 2D 网络，其中晶格 H2O 分子存在约 14%的充足自由体积。染料去除研究表明，1 在黑暗室温下从含有单染料或混合染料的水溶液中选择性吸附阴离子甲基橙（MO）和酸橙 7（AO7），而不是阳离子亚甲基蓝（MB）和孔雀石绿（MG）。实验等温线数据使用线性 Langmuir 和 Freundlich 等温线方程进行分析；结果表明，Langmuir 模型更适合于 1 吸附 MO 和 AO7，其黑暗吸附容量分别高达 810 和 370 mg g-1，尽管可能还有其他相关机制。MO 和 AO7 在 1 上的黑暗吸附动力学符合准二级动力学模型。静电吸引似乎是 1 吸附去除 MO 和 AO7 的主要机制，而 π-π 堆积（MO 和 AO7）和氢键相互作用（AO7）也可能起作用。MO 和 AO7 的吸附性能研究，包括在日光下研究动力学，得到的结果与黑暗中得到的结果相似，表明日光对染料去除的影响可以忽略不计。然而，1 在整个吸附实验过程中会将 NI-mbpy-44 和 Cu(ii)释放到水中，这可能是一种潜在的环境危害，这可能会导致二次污染，意味着 1 作为吸附剂候选物不切实际。
