Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5215865 | Tetrahedron | 2014 | 10 Pages |
Corroles and porphyrins are very promising probes to be used as materials for anion and metal ion detection. Here, we present the synthesis and characterization of two new corrole-coumarin derivatives 7-8 and some porphyrin-coumarin analogs 3-6.The sensing ability of the metalloconjugates was studied in the presence of spherical (Fâ, Clâ), linear (CNâ), and bulky anions (CH3COOâ). The porphyrin free-base conjugates were studied with Na+, Ca2+, Zn2+, Cd2+, Pb2+, Fe2+, Ba2+, Cu2+, Ag+, and Hg2+, showing a colorimetric effect (color change from purple to yellow) and an unprecedented selectivity for Hg2+.The insertion of coumarin moiety confers an unusual solubility of these conjugates in ethanol. One of the porphyrin free-base conjugate was fully studied in a mixture EtOH/H2O (50:50) and showed a similar behavior with Hg2+. Under these conditions, the conjugate presented a higher association constant than in toluene and was able to detect and quantify a minimal amount of 0.6Â ppm and 1.2Â ppm of Hg2+, respectively. Having in mind the biological and environmental application of these conjugates, non-expensive solid supports, like agarose and natural cellulose polymers were developed. In the cellulose support material (filter paper) the colorimetric effect for Hg2+ reveals a similar behavior as in solution.In addition pH studies carried out with the same conjugate showed a green color at low pH and a yellow color at high pH values in solution and in solid supports.
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