A multi-responsive luminescent sensor based on a super-stable sandwich-type terbium(iii)–organic framework

Abstract

A super-stable multifunctional terbium(iii)-organic framework, namely {[Tb(TATAB) (HO)]·NMP·HO} (Tb-MOF, HTATAB = 4,4',4''-s-triazine-1,3,5-triyltri-m-aminobenzoic acid, NMP = N-methyl-2-pyrrolidone) was synthesized. Tb-MOF exhibits a 2D sql structure with binuclear [Tb(COO)(HO)] units as 4-connected nodes, and free water and NMP molecules are inserted between 2D layers through hydrogen-bonding interactions, forming a sandwich-type architecture. Observably, such a framework remains intact in a remarkable variety of environments such as common solvents and aqueous solutions with metal cations and inorganic anions, as well as with a pH ranging from 1 to 13. In particular, Tb-MOF can not only detect small organic molecules, metal cations and inorganic anions with high sensitivity and high selectivity, but also can accurately detect explosive 2-nitrophenol, 3-nitrophenol, 4-nitrophenol and 2,4,6-trinitrophenol in water. Its luminescence quenching response to Fe and CrO ions can be explained in terms of the competitive absorption mechanism. In addition, the luminescence intensity of Tb-MOF is strongly correlated with the pH value in a pH range from 1 to 13. Thus, this material can be potentially used as a multi-responsive luminescent sensor.

Effects of template molecules on the structures and luminescence intensities of a series of porous Tb-MOFs based on the 2-nitroterephthalate ligand

“…The Tb-O bond lengths range from 2.292(2) to 2.601(3)Å, which are in accordance with those found in the other Tb(III) complexes. 13 The 2-ntp 2À ligand in 1 exhibits two m 4 coordination modes, (k 2 -k 1 )-(k 1 -k 1 )-m 4 and (k 1 -k 1 )-(k 1 -k 1 )-m 4 (Chart 1(a) and (b)), linking four Tb 3+ ions. The adjacent Tb 3+ ions (the Tb/Tb distances are 3.96 and 5.23Å) are bridged via carboxyl groups, in (k 2 -k 1 )-m 2 and (k 1 -k 1 )-m 2 modes, from 2-ntp ligands to form a one-dimensional chain with two kinds of rings, four-member rings and six-member rings, joining alternately, as shown in Fig.…”

A highly selective multifunctional Zn‐coordination polymer sensor for detection of Cr (III), Cr (VI) ion, and TNP molecule

“…Although some luminescent CPs have been recently explored for the determination of Cr (III), Cr (VI), and nitroaromatic compounds, respectively, it is still worth noting that few luminescent CPs can preserve their frameworks in acidic or basic environment, thus limit their applications as chemosensors because the coordination bonds of CPs might not be withstood the attack from acids or bases . Moreover, the structural diversity of CPs is mainly determined by the rational selection of metal centers and specific ligands, the commonly used ligands are carboxylic acids, N‐heterocyclic ligands, and containing N‐heterocyclic carboxylic acids, etc.…”

Two‐Dimensional MOF and COF Nanosheets: Synthesis and Applications in Electrochemistry

“…To maximize the utilization of energy, energy conversion, storage and environmental conservation have been extensively explored for reliable electrochemical application devices in recent years. Moreover, the endless electronic products and the constant updating of science and technology also require the energy materials with high performance to be used as electrode materials in electrochemical devices . In 2004, Geim and co‐workers first successfully separated graphene (a single‐layer graphite material), and started the research boom of two‐dimensional (2D) materials …”