Nickel(II)-Based Two-Dimensional Coordination Polymer Displaying Superior Capabilities for Selective Sensing of Cr(VI) Ions in Water

Abstract

Three fluorescent coordination polymers (CPs) including [Zn(ppvppa)(5-NO 2 -1,3-BDC)(H 2 O)] ( 1), [Cd-(ppvppa) Compound 1 has a onedimensional (1D) double-stranded chain structure. 2 and 3 have different two-dimensional (2D) grid-like networks formed by either bridging 1D [Cd(ppvppa) 2 ] n chains with 2,5-FDC ligands or linking 1D [Ni 2 (ppvppa) 2 ] n chains with 5-NO 2 -1,3-BDC ligands. The ligand ppvppa and the three CPs could detect Cr 2 O 7 2− and CrO 4 2− in aqueous solutions by selective fluorescence quenching. The detection limit of the most responsive complex 3 was 1.39 ppb for Cr 2 O 7 2− (pH = 4) or 0.09 ppb for CrO 4 2− (pH = 12), which are below the allowable limits set by the United States Environmental Protection Agency and European Union and the lowest among the known CPs-based sensors. The mechanism of such an emission quenching process may be ascribed to the overlap between the absorption band of the analyte and those of the excitation and emission bands of 3.

Polytorsional-amide/carboxylates-directed Cd(ii) coordination polymers exhibiting multi-functional sensing behaviors

“…In addition, the detection limits (LOD = 3 σ / K sv ) of CP 1 for MnO 4 − , CrO 4 2− and Cr 2 O 7 2− were calculated based on the K sv value and standard deviation ( σ ) of repeated fluorescence measurement of blank solution, and listed in the Table 2 . 11 Yong and Cui's groups synthesized several complexes for the detection of anions. 69,70 In contrast, the target complexes have higher fluorescence quenching constants, which are of great significance for the detection of anions (Table S5 † ).…”

“…Hexavalent chromium is an inhalant poison, which is one of the most allergenic metal elements. [11][12][13] It is easily absorbed by human body and has carcinogenic effect in specic parts such as lung and nasal cavity. 14,15 Potassium permanganate is a strong oxidizing substance, which is oen used in daily life to disinfect and remove peculiar smell.…”

“…According to the formula [I 0 À I]/I 0 Â 100% (I and I 0 are the same as mentioned above), the quenching efficiency is 94.1% for uorescence measurement of blank solution, and listed in the Table 2. 11 Yong and Cui's groups synthesized several complexes for the detection of anions. 69,70 In contrast, the target complexes have higher uorescence quenching constants, which are of great signicance for the detection of anions (Table S5 †).…”

A Water-Stable 2-Fold Interpenetrating cds Net as a Bifunctional Fluorescence-Responsive Sensor for Selective Detection of Cr(III) and Cr(VI) Ions

“…The World Health Organization (WHO) has claimed a permissible limit of 50 μg/L for Cr(VI) in drinking water [ 20 ]. Lately, MOF/CP-based, fluorescence-sensory materials have been actively pursued as excellent platforms for the flourishing utilization in detection of Cr(III) and Cr(VI) ions though fluorescence quenching (turn off) effect [ 15 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. However, there are still rare examples to achieve the detection of Cr(III) via the fluorescence enhancement (turn on) response [ 15 , 43 , 44 , 45 , 46 , 47 , 48 ] and fluorescence shift (ratiometric) effect [ 41 , 42 , 43 ].…”

Framework Materials Based on Naphthalenediimide Derivatives Supported by Aromatic Carboxylic Acids for Application as Multifunctional Fluorescence Sensors

“…Therefore, it is urgent to develop a more convenient detection method to detect Cr 2 O 7 2À ions quickly and accurately, using, for example, a fluorescence detection method. [13] Amino acids, as the basic components of proteins, [14] play a vital role in most aspects of the body, such as participating in metabolism, maintaining the normal redox environment of cells, and the balance of the central nervous system of the human body. [15,16] In the detection of amino acids, Fourier transform infrared spectroscopy (FT-IR), [17] high performance liquid chromatography, [18] capillary electrophoresis [19] mass spectrometry, [20] have shown excellent results.…”