Exploring the emissive properties of new azacrown compounds bearing aryl, furyl, or thienyl moieties: a special case of chelation enhancement of fluorescence upon interaction with Ca(2+), Cu(2+), or Ni(2+).
Three new compounds bearing furyl, aryl, or thienyl moieties linked to an imidazo-crown ether system (1, 2, and 3) were synthesized and fully characterized by elemental analysis, infrared, UV-vis absorption, and emission spectroscopy, X-ray crystal diffraction, and MALDI-TOF-MS spectrometry. The interaction toward metal ions (Ca(2+), Cu(2+), Ni(2+), and Hg(2+)) and F(-) has been explored in solution by absorption and fluorescence spectroscopy. Mononuclear and binuclear metal complexes using Cu(2+) or Hg(2+) as metal centers have been synthesized and characterized. Compounds 2 and 3 show a noticeable enhancement of the fluorescence intensity in the presence of Ca(2+) and Cu(2+) ions. Moreover compound 3 presents a dual sensory detection way by modification of the fluorimetric and colorimetric properties in the presence of Cu(2+) or Hg(2+). EPR studies in frozen solution and in microcrystalline state of the dinuclear Cu(II)3 complex revealed the presence of an unique Cu(2+) type.
REQUIMTE, Department of Chemistry, FCT-UNL, 2829-516 Monte de Caparica, Portugal.
Elisabete
E
Oliveira
Rosa M F
RM
Baptista
Susana P G
SP
Costa
M Manuela M
MM
Raposo
Carlos
C
Lodeiro
D002118:Calcium / Q000737:chemistry; D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D047248:Crown Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D009532:Nickel / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013053:Spectrophotometry
D002614:Chelating Agents; D047248:Crown Compounds; D005456:Fluorescent Dyes; D007093:Imidazoles; D008670:Metals; D003300:Copper; D009532:Nickel; D002118:Calcium