8‑Hydroxyquinolinate-Based Metal–Organic Frameworks: Synthesis, Tunable Luminescent Properties, and Highly Sensitive Detection of Small Molecules and Metal Ions

• Published in: Inorganic chemistry Vol. 58; no. 4; pp. 2444 - 2453
• Main Authors: Zhao, Xiangxiang, Wang, Shilin, Zhang, Liyan, Liu, Suya, Yuan, Guozan
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 18.02.2019
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.8b03001

Five new metal–organic frameworks, [Zn2L2]·2DMF·2MeOH (1), [Zn2L2(py)2] (2), [Cd2L2]·Diox·MeOH·6H2O (3), [Mn2L2]·2DMF·2MeOH (4), and [Co2L2]·2DMF·4H2O (5), were assembled by using a novel 8-hydroxyquinolinate derivative H2L with different metal ions. Complex 1 features a 3D porous network consisting of meso-helical chains (P + M) built from metal–ligand coordination bonds. The adjacent dinuclear ZnII building blocks in 2 are connected together to generate a 2D grid network. In complex 3, each binuclear motif is bound to four ZnII ions to produce a 2D layer structure that stacks into a 3D porous structure. The framework of complex 4 is isostructural to 5, featuring a 21 helical chain built from [M2L2] units (M = Mn or Co). The adjacent meso-helices associated in parallel are interconnected by the phenolate μ2-O atoms of H2L to give rise to a 2D network. Distinct solid-state luminescence properties of 1–3 were observed, arising from their different metal nodes and frameworks. In particular, complex 1 exhibited excellent stability in both common organic solvents and H2O, thus facilitating its utility as a chemical sensor. Remarkably, luminescent 1 showed highly sensitive detection for nitroaromatic molecules in methanol and Fe3+ ion in H2O even in the presence of other interfering metal cations.