Wang Wenbo, Wang Ruiying, Ge Yafang, Wu Benlai
College of Chemistry and Molecular Engineering, Zhengzhou University Zhengzhou 450001 P. R. China
School of Chemical Engineering, Henan Vocational College of Applied Technology Zhengzhou 450042 P. R. China.
RSC Adv. 2018 Dec 18;8(73):42100-42108. doi: 10.1039/c8ra06793g. eCollection 2018 Dec 12.
Four lanthanide-based homochiral metal-organic frameworks (Ln-HMOFs), {[Ln(HL)(HO)]·2Cl·5HO} [Ln = Gd (1), Eu (2), Tb (3) and Dy (4)], have been synthesized through solvothermal reactions of chiral ligand ()-5-(((1-carboxyethyl)amino)methyl)isophthalic acid (HL) with corresponding LnCl·6HO. They are binodal (3,6)-connected frameworks with kgd nets based on binuclear cluster units and zwitterionic (HL) linkers. Considering the isostructuralism of these Ln-HMOFs as well as the blue emission of compound 1 and the strong typical Eu and Tb emissions of compounds 2 and 3, single-phase mixed-lanthanide HMOFs have been prepared by doping of Ln into the Ln-HMOFs to modulate light-emitting color. Interestingly, the bimetallic doped Eu/Tb-HMOFs [(Eu Tb )(HL)(HO)]·2Cl·5HO display a fluent change of light-emitting color among green, yellow, orange, orange-red, and red by adjusting the doping concentration of Eu ions into the Tb-HMOF. Very importantly, the trimetallic doped Eu/Gd/Tb-HMOF [(EuGdTb)(HL)(HO)]·2Cl·5HO emits white light upon excitation at 355 nm, whose emission can also be switched between different colors when excited with different ultraviolet light. Furthermore, the fluorescence response of Tb-HMOF to various usual metal ions, and especially fluorescent sensing behaviours to Fe, Cr and Al have been preliminarily investigated.
通过手性配体（）-5-（（（1-羧乙基）氨基）甲基）间苯二甲酸（HL）与相应的LnCl₃·6H₂O进行溶剂热反应，合成了四种基于镧系元素的同手性金属有机框架（Ln-HMOFs），{[Ln(HL)(H₂O)]·2Cl·5H₂O} [Ln = Gd (1)、Eu (2)、Tb (3) 和 Dy (4)]。它们是基于双核簇单元和两性离子（HL）连接体的具有kgd网络的双节点（3,6）连接框架。考虑到这些Ln-HMOFs的同构性以及化合物1的蓝色发射和化合物2和3强烈的典型Eu和Tb发射，通过将Ln掺杂到Ln-HMOFs中来调节发光颜色，制备了单相混合镧系HMOFs。有趣的是，双金属掺杂的Eu/Tb-HMOFs [(EuₓTb₁₋ₓ)(HL)(H₂O)]·2Cl·5H₂O通过调节Eu离子在Tb-HMOF中的掺杂浓度，在绿色、黄色、橙色、橙红色和红色之间呈现出发光颜色的流畅变化。非常重要的是，三金属掺杂的Eu/Gd/Tb-HMOF [(EuₓGdₙTb₁₋ₓ₋ₙ)(HL)(H₂O)]·2Cl·5H₂O在355 nm激发下发射白光，当用不同的紫外光激发时，其发射也可以在不同颜色之间切换。此外，还初步研究了Tb-HMOF对各种常见金属离子的荧光响应，特别是对Fe、Cr和Al的荧光传感行为。
