Photoluminescent Coordination Polymers Based on Group 12 Metals and 1H-Indazole-6-Carboxylic Acid

Abstract

Two new coordination polymers (CPs) based on Zn(II) and Cd(II) and 1H-indazole-6-carboxylic acid (H2L) of general formulae [Zn(L)(H2O)]n (1) and [Cd2(HL)4]n (2) have been synthesized and fully characterized by elemental analyses, Fourier transformed infrared spectroscopy and single crystal X-ray diffraction. The results indicate that compound 1 possesses double chains in its structure whereas 2 exhibits a 3D network. The intermolecular interactions, including hydrogen bonds, C–H···π and π···π stacking interactions, stabilize both crystal structures. Photoluminescence (PL) properties have shown that compounds 1 and 2 present similar emission spectra compared to the free-ligand. The emission spectra are also studied from the theoretical point of view by means of time-dependent density-functional theory (TD-DFT) calculations to confirm that ligand-centred π-π* electronic transitions govern emission of compound 1 and 2. Finally, the PL properties are also studied in aqueous solution to explore the stability and emission capacity of the compounds.

A Cr(iii) supramolecular network composite membrane with high water stability and proton conductivity

“…Nitrogen-containing heterocycles and carboxylic acid derivatives contain N atoms and O atoms in their molecular structure and are easy to coordinate with transitional metal ions, so they are often used to synthesize supramolecular hydrogen-bond complexes. 21…”

“…Nitrogen-containing heterocycles and carboxylic acid derivatives contain N atoms and O atoms in their molecular structure and are easy to coordinate with transitional metal ions, so they are often used to synthesize supramolecular hydrogen-bond complexes. 21 Most of the polymer materials used for the preparation of polymer films, such as polyvinylidene fluoride (PVDF), 22 polyvinyl alcohol (PVA), 23 and polyacrylonitrile (PAN), 11 either have poor affinity binding sites or lack of stability in water. 24 Due to this, the blending matrix membrane will result in a composite membrane with the advantages of individual components.…”

Palladium‐Catalyzed Site‐Selective C7 Oxidative Arylation of 4‐EWG‐1H‐Indazoles

“…Due to their biological properties, 1H-indazole molecules are extensively studied in organic chemistry, [16] material science, [17,18] and nanotechnology. [19,20] Nevertheless, the regioselective functionalization at the six membered ring still remains a challenging task.…”