College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang 455000, Henan, P. R. China.
Dalton Trans. 2018 Jun 12;47(23):7787-7794. doi: 10.1039/c8dt00908b.
Based on the inner filter effect, a luminescent Zn(ii)/Na(i) metal-organic framework (MOF) {[Zn2Na(L)(HL)2(H2O)2][OAc]·2H2O}n (1, H2L = 5-methyl-1,3-benzenedicarboxylic acid) with excellent stability was constructed for the fluorescence detection of Cu2+ ions. MOF 1 holds a 3D cationic framework in which [(OAc)2(H2O)2]n2n- anions are embedded into its 1D channels. Abundant hydrogen-bonding and π-π interactions in the MOF facilitate electron transfer from ligand-to-metal, resulting in a good luminescence peak at 412 nm and an efficient fluorescence quenching of MOF 1 in the presence of Cu2+ ions, due to the inner filter effect. The interactions between the Cu2+ ions and the OAc- anion in the channel endowed the Cu2+ ions with facile access to be adsorbed, and afforded the selective quenching of fluorescence. The MOF particles are well dispersed in water and the Cu2+ ions are pre-concentrated by adsorption, thus facilitating the determination of Cu2+ ions with a detection limit down to 0.65 μM. Our work thus paves a way for developing MOFs as an appealing platform to construct materials for environmental applications.
基于内滤效应，构建了一种发光的 Zn(ii)/Na(i) 金属有机骨架（MOF）{[Zn2Na(L)(HL)2(H2O)2][OAc]·2H2O}n（1，H2L = 5-甲基-1,3-苯二甲酸），具有优异的稳定性，可用于荧光检测 Cu2+离子。MOF 1 具有 3D 阳离子骨架，其中 [(OAc)2(H2O)2]n2n-阴离子嵌入其 1D 通道中。MOF 中丰富的氢键和 π-π 相互作用促进了从配体到金属的电子转移，导致在存在 Cu2+离子时，在 412nm 处出现良好的发光峰，并有效地猝灭 MOF 1 的荧光，这归因于内滤效应。通道中 Cu2+离子与 OAc-阴离子之间的相互作用使 Cu2+离子易于被吸附，从而实现了对荧光的选择性猝灭。MOF 颗粒在水中良好分散，Cu2+离子通过吸附进行预浓缩，从而有利于以检测限低至 0.65 μM 的方式测定 Cu2+离子。我们的工作为开发 MOFs 作为构建环境应用材料的有吸引力的平台铺平了道路。
