Síntese, caracterização e estudo fotoquímico de formação do complexo de cobre [CuI/II(mbpy-pyr)2]

Abstract

The development of probes capable of binding to transition metals has attracted widely attention due to its important application of biological and environment. The pyrene fluorophore has been investigated for this purpose. The compound mbpy-pyr (4'-methyl-4- (iminepyrenyl)-2,2'-bipyridine) was synthesized in view of obtaining a fluorescent coordinating ligand. This compound was characterized by spectroctrochemical techniques as UV-Vis, IR, NMR and fluorescence. After coordination to the Cu(II) metal ion, two absorption bands appear in the UV-Vis spectra, one strong absorption band at 453 nm assigned to the ligand-metal charge transfer transition and another weak band at 764 nm due to d-d transition. The stoichiometry of complex formation is 2:1 (ligand:metal) with binding constant of about 109. The cyclic voltammogram of [CuI/II(mbpy-pyr)2] complex shows two oxidation waves (219 e 358 mV) and one reduction wave (97 mV), indicating that the two reduction processes are overlapped. All the results suggest that the mbpy-pyr ligand is eficiente for detection of Cu(II) ions.