Construction of a Stable Lanthanide Metal-Organic Framework as a Luminescent Probe for Rapid Naked-Eye Recognition of Fe3+ and Acetone

Abstract

Four lanthanide metal-organic frameworks (Ln-MOFs), namely {[Me2NH2][LnL]·2H2O}n (Ln = Eu 1, Tb 2, Dy 3, Gd 4), have been constructed from a new tetradentate ligand 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid (H4L). These isostructural Ln-MOFs, crystallizing in the monoclinic P21/c space group, feature a 3D structure with 7.5 Å × 9.8 Å channels along the b axis and the point symbol of {410.614.84} {45.6}2. The framework shows high air and hydrolytic stability, which can keep stable after exposed to humid air for 30 days or immersed in water for seven days. Four MOFs with different lanthanide ions (Eu3+, Tb3+, Dy3+, and Gd3+) ions exhibit red, green, yellow, and blue emissions, respectively. The Tb-MOF emitting bright green luminescence can selectively and rapidly (<40 s) detect Fe3+ in aqueous media via a fluorescence quenching effect. The detection shows excellent anti-inference ability toward many other cations and can be easily recognized by naked eyes. In addition, it can also be utilized as a rapid fluorescent sensor to detect acetone solvent as well as acetone vapor. Similar results of sensing experiments were observed from Eu-MOF. The sensing mechanism are further discussed.

Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72− in H2O

“…Luminescent coordination polymers (CPs) or metal-organic frameworks (MOFs) or hydrogen-bonded organic frameworks (HOFs) have received much attention, attributing the success to their potential applications in photocatalysis, biomedical imaging and fluorescent sensors [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 67 ]. The solid-state fluorescence properties of 1 and 2 were investigated at room temperature.…”

“…HOFs have attracted a significant deal of attention especially because of their broad applications, ranging from chemical sensing [ 6 ] and bioimaging [ 7 , 8 ] to lighting [ 9 ] and 3D optical storage [ 10 , 11 ]. The metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) are usually connected by coordination bonds or covalent bonds between atoms and show relatively high stabilities [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], while the HOFs are linked by weak non-covalent interactions, such as hydrogen bonds and π−π stacking interactions, and exhibit relatively low stabilities [ 21 , 22 , 23 , 24 , 25 ]. For HOFs, the solvent guests play important roles in the construction of the supermolecular network system.…”

Mono- and Mixed Metal Complexes of Eu3+, Gd3+, and Tb3+ with a Diketone, Bearing Pyrazole Moiety and CHF2-Group: Structure, Color Tuning, and Kinetics of Energy Transfer between Lanthanide Ions

“…The unique luminescent properties of lanthanide ions are actively studied due to the possibility of their use in emitting materials [ 1 , 2 , 3 ], biovisualization [ 4 , 5 , 6 , 7 ], banknote protection [ 8 ] and in creating sensing materials [ 9 , 10 , 11 ].…”

Construction of a Luminescent Cadmium-Based Metal–Organic Framework for Highly Selective Discrimination of Ferric Ions

“…Iron ions are an important component of hemoglobin and myoglobin but are also related to transferrin. In addition, the level of iron ions content has a profound impact on industrial and agricultural production, as well as daily life [1][2][3][4][5]. Therefore, the detection of iron ions is of great significance for environmental detection and life science.…”