Macrocyclization of N,N′-propylenebis(3-formyl-5-tert-butylsalicylaldimine): a ratiometric fluorescence chemodosimeter for ZnII
| Autor: | Jaydeep Adhikary, Tonmoy Chakraborty, Debasis Das, Prateeti Chakraborty, Sudhanshu Das |
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| Rok vydání: | 2016 |
| Předmět: |
Quenching (fluorescence)
Chemistry Ligand General Chemical Engineering Metal ions in aqueous solution Imine chemistry.chemical_element 02 engineering and technology General Chemistry Zinc 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Zinc nitrate Diamine Polymer chemistry Lewis acids and bases 0210 nano-technology |
| Zdroj: | RSC Advances. 6:98620-98631 |
| ISSN: | 2046-2069 |
| DOI: | 10.1039/c6ra05478a |
| Popis: | Addition of 1,3-propane diamine to 2,6-diformyl-4-tert-butyl phenol in ethanol produces a site-selective imination product N,N′-propylenebis(3-formyl-5-tert-butylsalicylaldimine), an acyclic side-off compartmental ligand (H2L). In the presence of zinc nitrate the ligand goes on hydrolysis in 50 : 50 water–acetonitrile medium and forms a partially hydrolyzed ligand (H2L′) which slowly metallates to generate a macrocyclic dinuclear zinc(II) complex (1), as characterized by single crystal X-ray analyses. The formation of H2L′ is believed to occur through the cleavage of an imine bond of the acyclic compartmental ligand (H2L) in the presence of zinc nitrate which acts as a Lewis acid. The formation of H2L′ has been monitored by means of 1H NMR and further confirmed by HRMS spectroscopic studies. The interactions of H2L with nickel(II) and copper(II) nitrate produce dinuclear complexes 2 and 3 (reported in Inorg. Chem. Commun. 2012, 15, 266–268) respectively, which are formed with unchanged ligand. Various spectroscopic techniques have been used to further characterize the complexes. H2L hardly exhibits yellowish green fluorescence emission at 523 nm when excited at 437 nm in 1 : 1 water–acetonitrile. Upon addition of Zn2+, a new fluorescence emission band at 481 nm appears, the intensity of which slowly enhances. Thus, the ligand H2L is a ratiometric fluorescence chemodosimeter for the selective detection of Zn2+ ions. On addition of CaII, MgII, NaI and KI in the same concentrations as that of Zn2+, the emission band at 523 nm is slightly enhanced, whereas the addition of paramagnetic metal cations like CuII, FeII, NiII, CoII, and MnII resulted in quenching of fluorescence. The quenching effect is also observed in the presence of CdII, a d10 metal cation exhibiting similar coordination properties to ZnII. The ZnII ion selectivity has also been studied in the presence of other biologically relevant metal ions in 50 : 50 water–acetonitrile. |
| Databáze: | OpenAIRE |
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