Cadmium(II)–Triazole Framework as a Luminescent Probe for Ca²⁺ and Cyano Complexes

Abstract

A bidentate ligand, 1-{4-[4-(1H-1,2,4-triazol-1-yl)phenoxy]phenyl}-1H-1,2,4-triazole (TPPT), has been designed and synthesized. By using TPPT as a building block for self-assembly with Cd(NO3 )2 ⋅4 H2 O and CdCl2 ⋅10.5 H2 O, novel 1D double-chain {[Cd(TPPT)(NO3 )2 ]⋅3 H2 O}n (1) and 2D (4,4) layer [Cd(TPPT)Cl2 (H2 O)]n (2) have been constructed. When 1 was employed as a precursor and exposed to DMF or N,N'-dimethylacetamide (DMAC), the crystals of 1 dissolved and reassembled into two types of brown block-shaped crystals of 1D double chains: {[Cd(TPPT)2 (NO3 )2 ]⋅DMF}n (1 a) and {[Cd(TPPT)2 (NO3 )2 ]⋅DMAC}n (1 b). The anion-exchange reactions of complex 2 have also been investigated. After gently stirring crystals of 2 in CHCl3 /C2 H5 OH/H2 O containing NaBr, NaI⋅2 H2 O, or NaOAc⋅3 H2 O, the crystals retained their crystalline appearances. A remarkable single crystal to single crystal transformation was observed and 1D double chains of {[Cd(TPPT)Br2 ]⋅C2 H5 OH}n (2 a) and {[Cd(TPPT)2 I2 ]⋅CHCl3 }n (2 b), and 1D single chains of [Cd(TPPT)(H2 O)2 (CH3 COO)2 ]n (2 c), can be obtained. Luminescent properties indicate that 1 shows excellent selectivity for Ca(2+) and cyano complexes. To the best of our knowledge, this is the first example of a luminescent probe for Ca(2+) based on triazole derivatives.

A Highly Efficient Luminescent Metal–Organic Framework with Strong Conjugate Unit for Sensing Small Molecules

“…As is well‐known, the emission of organic ligands embracing rich π electron is usually attributed to π* → π and/or π* → n electronic transition. [ 42‐44 ] The solid state emission peak of JXUST‐10 ensues at 466 nm ( λ ex = 394 nm), which just respectively shows the slight shifts of 14 nm and 18 nm, compared with the free ligands BBZB and 2,6‐NDC. Therefore, the fluorescence behaviour of JXUST‐10 may be caused by the metal‐perturbed intraligand charge transition in the framework.…”

Stable bifunctional ZnII-based sensor toward acetylacetone and l-histidine via a fluorescence red shift and turn-on effect

“…S4 (ESI†), the emission bands of bbip, NH 2 –H 2 BDC and JXUST-15 are at 374 nm ( λ ex = 345 nm), 560 nm ( λ ex = 370 nm) and 425 nm ( λ ex = 367 nm), respectively. The emission of organic ligands is usually attributed to the π* → π and/or π* → n electronic transitions, 52 and the emission of JXUST-15 should largely correspond to the metal-perturbed intraligand charge transfer because of the d 10 electron configuration of Zn II . Moreover, compared with the NH 2 -H 2 BDC ligand, the obvious blue shift of the emission band for JXUST-15 may be on account of the metal–ligand coordination interactions.…”

A CdII‐Based Metal‐Organic Framework with pcu Topology as Turn‐On Fluorescent Sensor for Al3+

“…Strong emissions of H 2 ndc and JXUST‐1 were observed at about 485 nm and 404 nm upon excitation at 375 nm and 354 nm, respectively (Figure ). To our knowledge, the emission of organic ligand constituted from σ and π bonds is usually ascribed to π*→n and/or π*→π electronic transitions . The emission of JXUST‐1 may be due to the metal‐perturbed intraligand charge transferring owing to the d 10 electron configuration of Cd II .…”