A Cobalt-Organic Framework with Sensitive Detection of Fe3+, Cr2O72–, and CrO42– Ions in Water

Abstract

A six-coordinated 3D metal-organic framework (MOF), namely, [Co(BPDC)(3-bpdb)(H 2 O) 2 ] n (1) (H 2 BPDC = 4,4′-biphenyldicarboxylic acid, 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene) was purposefully constructed and characterized by single-crystal XRD, IR, elemental analyses, PXRD, SEM, and TGA. Crystal structural analysis revealed that the complex consists of a cds-type three-fold interpenetrated framework.Hirshfeld surface analysis yielded details of the surface characteristics of 1. Signi cant O−H•••O hydrogen bonding interactions, which could promote the stability of the framework, were found is extremely stable in aqueous solution and can resist acids and bases over an extensive pH range of 2 -13. 1 shows brilliant uorescent emission in the solid state and in aqueous solution. Fluorescence titration, cyclic, and antiinterference experiments demonstrated that 1 is an excellent probe for Fe 3+ , CrO 4 2and Cr 2 O 7 2in water.The K sv values of 1 for Fe 3+ , CrO 4 2-, and Cr 2 O 7 2-, which were as high as 1.06 × 10 4 M −1 , 1.50 × 10 4 M −1 , and 1.16 × 10 4 M −1 , respectively, were comparable with those of other sensors. The quenching mechanism of the novel probe was subsequently explained.

Zn(II) and Cd(II) Metal–Organic Frameworks with Azine-Functionalized Pores: Crystal Structures, Photoluminescence, Solvent Exchange, and Molecular Simulations of Carbon Dioxide Binding Sites

“…MOFs obtained from the combination of H 2 (bpdc) with N , N ′-azine donor ligands are scarce − and include [Co 2 (bpdc) 2 (4-bph)·3dmf] n and [Cd 2 (bpdc) 2 (4-bph) 2 ·2dmf] n [bph = bis­(pyridinylethylidene)­hydrazine] with “single-pillared” and “double-pillared” MOF-5-like motifs, {[Zn 3 (μ 4 -bpdc) 3 (μ-bpdb)]·5dmf} n and {[Zn 2 (μ 4 -bpdc) 2 (μ-bpdb)]·7dmf} n [bpdb = 1,4-bis­(4-pyridyl)-2,3-diaza-1,3-butadiene] with doubly interpenetrated pcu networks. , Compound [Co­(bpdc)­(3-bpdb)­(H 2 O) 2 ] n revealed sensitive detection of Fe 3+ , Cr 2 O 7 2– , and CrO 4 2– ions in water …”

A Water-Soluble Naphthalimide-Based Fluorescent Probe for Specific Sensing of Fe3+ and $\text{C}{{\text{r}}_{2}}\text{O}_{7}^{2-}$

“…With the rapid development of modern industry and ag-riculture, more and more toxic heavy metal ions, inorganic anions, small organic molecules, antibiotics and pesticides enter the environment and become the main pollution source in water. [1][2] Therefore, it inevitably poses a serious threat to human life, health and living environment. [3][4] Fe 3 ＋ is an essential trace element in organisms.…”

“…[8,17,26,35] In contrast, fluorescent probe detection has the characteristics of high selectivity, high sensitivity, low cost, rapid response, visualization and biological imaging, which can make up for the shortcomings of traditional analytical methods. [11,[15][16]24,37] At present, there are many reports on fluorescence sensing for the detection of Fe 3 ＋ , including organic small molecules, [4][5][6][11][12]16,18,20,26] metal organic frameworks [2,[7][8]10,38,[40][41][42] , quantum dots and so on. [9,[13][14][15]39,43] However, when considering the practical application ability of the probe in selectivity, sensitivity, competitiveness and applicable conditions, researchers believe that there is still a need for development and progress for Fe 3 ＋ fluorescent sensors.…”

“…[9,[13][14][15]39,43] However, when considering the practical application ability of the probe in selectivity, sensitivity, competitiveness and applicable conditions, researchers believe that there is still a need for development and progress for Fe 3 ＋ fluorescent sensors. [6,11,15,39] Compared with the fluorescence sensor of Fe 3 ＋ , there are fewer reports on the fluorescence sensor of Cr O -, and most of them are based on metal-organic framework (MOFs) sensors, such as Zn-MOFs, [1,[31][32][35][36]44] Cd-MOFs, [25,[33][34]45] Co-MOFs, [2] In-MOFs, [46] Eu-MO-Fs, [47] Mn-MOFs, [48] Zr-MOFs [28] and Pb-MOFs. [48] Although the preparation process of MOFs sensors is relatively simple, it is not enough safe, convenient and quick, because the preparation or detection process may cause metal ions such as Zn 2 ＋ , Co 2 ＋ , Cd 2 ＋ , Eu 2 ＋ , Mn 2 ＋ , Pb 2 ＋ to enter the environment, and most of the detection processes require ultrasonic treatment or room temperature storage for a certain time.…”