Solvent-Induced Controllable Supramolecular Isomerism: Phase Transformation, CO₂ Adsorption, and Fluorescence Sensing toward CrO₄^2–, Cr₂O₇^2–, MnO₄^–, and Fe³⁺

Abstract

Complexes {[Zn(bpdc)(Cz-3,6-bpy)]•DMF•H 2 O} n (1α-DMF, H 2 bpdc = biphenyl-4,4′-dicarboxylic acid, Cz-3,6-bpy = 3,6-bis(pyridine-4-yl)-9H-carbazole, DMF = N,N′-dimethylformamide) and {[Zn(bpdc)(Cz-3,6-bpy)]• 2DMAc•H 2 O} n (1β-DMAc, DMAc = N,N′-dimethylacetamide) as a couple of solvent-induced supramolecular isomers were hydro(solvo)thermally synthesized using DMF/H 2 O and DMAc-only as reaction media, respectively. Complexes 1α-DMF and 1β-DMAc adopt very similar wavy sql sheet structures but present great differences in the 3-fold interweaving 2D → 2D nets, which result in free voids of 17.6 and 33.4%, respectively. Desolvated 1β has about 2 times the free voids compared to that of desolvated 1α; however, the former displays a CO 2 uptake of 87.9 cm 3 g −1 STP at 195 K and P/P 0 = 1 which is only slight larger than that (73.7 cm 3 g −1 STP) of the latter under the same conditions. This is mainly interpreted by activation-and adsorption-induced framework distortion that caused partial transformation of crystal phase from 1β to 1α and thus reduced free voids. The isosteric heat of CO 2 adsorption (Q st ) at zero loading is 29.8 kJ mol −1 for desolvated 1α and 30.6 kJ mol −1 for desolvated 1β. On the other hand, results from XRPD, IR, and TGA measurements imply that 1α-DMF and 1β-DMAc are highly stable in several different solvents, with the exception of 1α-DMF in DMAc, which experienced complete transformation to convert to 1β-DMAc and 1β-DMAc in acetone and methanol, which would respectively completely and partially transform to the crystal phase of 1α-DMF. Remarkably, 1α-DMF and 1β-DMAc display intense blue and cyan fluorescence emissions, respectively, promising them to be multifunctional sensing platforms in sensitive detection of CrO 4 2− , Cr 2 O 7 2− , MnO 4 − , and Fe 3+ with high selectivity and a fairly low limit of detection through perceptible fluorescence quenching effect. The possible sensing mechanisms were also investigated.

Three Zn(II) coordination polymers as dual‐responsive luminescent probes for highly selective detection of Fe3+ cation and MnO4− anion

“…By fitting, K sv values were about 2.6×10 4 M −1 for LCP 1 , 1.5×10 3 M −1 for LCP 2 , and 2.8×10 4 M −1 for LCP 3 . The LOD were 3.93×10 −6 M for LCP 1 , 6.62×10 −5 M for LCP 2 , and 3.64×10 −6 M for LCP 3 (Table S7), which were values comparable to other reported CP‐based sensors of MnO 4 − with excellent performances [1,15,32–35] . Next, the anti‐interference ability of LCPs 1 – 3 was studied.…”

“…À with excellent performances. [1,15,[32][33][34][35] Next, the anti-interference ability of LCPs 1-3 was studied.…”

Water-Robust Zinc–Organic Framework with Mixed Nodes and Its Handy Mixed-Matrix Membrane for Highly Effective Luminescent Detection of Fe3+, CrO42–, and Cr2O72– in Aqueous Solution

“…As shown in Figure , the S–V curves for Fe 3+ , CrO 4 2– , and Cr 2 O 7 2– show a good linear correlation ( R 2 = 0.99, 0.97, and 0.99) in the concentration ranges of 0–0.1, 0–0.183, and 0–0.21 mM, respectively. The calculated K SV of Fe 3+ is 42210.27 M –1 , which is much higher than those in some reported works. ,, Furthermore, the LOD of compound 1 toward Fe 3+ is calculated by using the equation of LOD = 3σ/slope (σ = standard deviation) with a low LOD of 1.06 μM. Meanwhile, the K SV and LOD of compound 1 toward CrO 4 2– /Cr 2 O 7 2– are 11605.28 M –1 and 3.87 μM and 18972.72 M –1 and 2.37 μM, respectively.…”

Structural transformation of copper coordination complexes accompanied with chiral transformation

“…32–34 Detailed changes in the crystal structure are exhibited during the transformation and offer the opportunity to explore the reaction mechanism at the atomic level, such as the addition and removal of solvent or guest molecules. 28,35–41 Chirality is also a universal feature in nature and living organisms, and chiral complexes show unique properties including circular dichroism (CD), circularly polarized luminescence (CPL), optical rotation, chiroptical switching processes, and nonlinear optical (NLO) activity. 42–48 When structural transformation meets chirality, the generation, reversal and disappearance of chiral structures is of considerable interest.…”