An interesting ligand for the preparation of luminescent plastics: the picrate ion

• Autor(a) principal: Zea Bermudez, V. de
• Data de Publicação: 2000
• Outros Autores: Carlos, Luís, Silva, Maria Manuela, Smith, Michael John
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/1822/32430
• topic: Solid polymer electrolytes; Luminescence; X-ray diffraction; Infrared spectroscopy; Ciências Naturais::Ciências Físicas; Ciências Naturais::Ciências Químicas; Science & Technology

Electrolytes formed with poly(oxyethylene), POE, and europium picrate [Eu(pic)2(OH2)6]pic.6H2O (where pic denotes the picrate anion) or simply Eu(pic)3xH2O, have been represented by POEnEu(pic)3xH2O (where n represents the molar ratio of (OCH2CH2) units per Eu3+ ion). Materials with n ranging from 133 to 11 have been examined. A tentative attribution of the absorption bands of the mid-infrared spectra is presented. The spectral changes detected in the mid-infrared region and the modifications in the XRD patterns at increasing salt content show that PEOnEu(pic)3xH2O exerts an effective plasticizing role which leads to the complete supression of crystallinity at n = 11. The emission spectra of the complexes and their signature in the vC-O spectral region provide conclusive evidence that the Eu3+ ions are coordinated to the oxygen atoms of the polyether chains over the whole range of compositions studied. The photoluminescence spectra of the PEOnEu(pic)3xH2O electrolytes indicate that the Eu3+/ether oxygen complexation occurs with concomittant partial substitution of the water molecules from the cation coordination shell. The luminescence data obtained