title: Synthesis, spectroscopy studies, and theoretical calculations of new fluorescent probes based on pyrazole containing porphyrins for Zn(II), Cd(II), and Hg(II) optical detection.
abstract: New pyrazole-porphyrin conjugates were successfully prepared from a reaction of β-porphyrin-chalcone derivatives with phenylhydrazine in acetic acid followed by an oxidative step. This fast and efficient synthetic approach provided the expected compounds in yields up to 82%. The sensing ability of the new porphyrin-pyrazole derivatives to detect the metal ions Ag(+), Na(+), K(+), Mg(2+), Ca(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+), Pb(2+), and Cr(3+) was studied by spectrophotometric and spectrofluorimetric titrations. In the presence of Zn(2+), the conjugates exhibit changes in the emission spectra that are desired for a ratiometric-type fluoroionophoric detection probe. The studies were extended to gas phase, where the pyrazole-porphyrin conjugates show ability to sense metal ions with high selectivity toward Cu(2+) and Ag(+), and in poly(methyl methacrylate) doped films with promising results for Zn(2+) detection.
authors.affiliation: Department of Chemistry and QOPNA, University of Aveiro , 3810-193 Aveiro, Portugal.
authors.forename: Nuno M M
authors.initials: NM
authors.lastname: Moura
authors.forename: Cristina
authors.initials: C
authors.lastname: Núñez
authors.forename: Sérgio M
authors.initials: SM
authors.lastname: Santos
authors.forename: M Amparo F
authors.initials: MA
authors.lastname: Faustino
authors.forename: José A S
authors.initials: JA
authors.lastname: Cavaleiro
authors.forename: M Graça P M S
authors.initials: MG
authors.lastname: Neves
authors.forename: José Luis
authors.initials: JL
authors.lastname: Capelo
authors.forename: Carlos
authors.initials: C
authors.lastname: Lodeiro