Complexes {[Zn(bpdc)(Cz-3,6-bpy)]·DMF·H₂O}_n (1α-DMF, H₂bpdc = 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·H₂O}_n (1β-DMAc, DMAc = N,N′-dimethylacetamide) as a couple of solvent-induced supramolecular isomers were hydro(solvo)thermally synthesized using DMF/H₂O 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 CO₂ uptake of 87.9 cm³ g^–1 STP at 195 K and P/P₀ = 1 which is only slight larger than that (73.7 cm³ 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 CO₂ 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 CrO₄^2–, Cr₂O₇^2–, MnO₄^–, and Fe³⁺ with high selectivity and a fairly low limit of detection through perceptible fluorescence quenching effect. The possible sensing mechanisms were also investigated.

中文翻译：

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溶剂诱导的可控超分子异构：相变，CO2吸附和对CrO42-，Cr2O72-，MnO4-和Fe3的荧光传感。

配合物{[Zn（bpdc）（Cz-3,6-bpy）]·DMF·H ₂ O} _n（1α- DMF，H ₂ bpdc =联苯-4,4'-二羧酸，Cz-3,6- bpy = 3,6-双（吡啶-4-基）-9 H-咔唑，DMF = N，N'-二甲基甲酰胺）和{[Zn（bpdc）（Cz-3,6-bpy）]·2DMAc·H分别使用DMF / H ₂ O和仅DMAc作为反应介质水热合成₂ O} _n（1β -DMAc，DMAc = N，N'-二甲基乙酰胺）作为溶剂诱导的超分子异构体。配合物1α- DMF和1β-DMAc采用非常相似的波浪sql表格结构，但是在3D交织2D→2D网络中存在很大差异，分别导致17.6％和33.4％的自由空隙。去溶剂化的1β的游离空隙是去溶剂化的1α的2倍; 但是，前者在195 K和P / P ₀ = 1时显示的CO ₂吸收量为87.9 cm ³ g ^–1 STP，仅略大于（73.7 cm ³ g ^–1STP）在相同条件下。这主要由活化和吸附引起的骨架变形解释，该变形导致晶体相从1β到1α的部分转变，从而减少了空洞。零负荷时，CO ₂吸附的等位热（Q _st）对于去溶剂化的1α为29.8 kJ mol ^–1，对于对溶剂化的1β为30.6 kJ mol ^–1。另一方面，XRPD，IR和TGA测量的结果表明1α- DMF和1β- DMAc在几种不同的溶剂中具有高度稳定性，但1α除外DMAc中的-DMF经历了完全转化，在丙酮和甲醇中分别转化为1β- DMAc和1β- DMAc，这将分别完全和部分转化为1α- DMF的结晶相。值得注意的是，1α- DMF和1β- DMAc分别显示出强烈的蓝色和青色荧光发射，从而使它们成为敏感检测CrO ₄ ^2–，Cr ₂ O ₇ ^2–，MnO ₄ ^–和Fe ^3+的多功能传感平台。通过可察觉的荧光猝灭作用具有很高的选择性和相当低的检测限。还研究了可能的传感机制。