The complexes tris(4,4,4-Trifluoro-1-(1-naphthyl)-1,3-butanedionate) (2,2 0 -bipiridyl) Ln(III), Ln(tan) 3 bipy, where Ln(III) ¼ Eu 3+ and Gd 3+ have been synthesized, characterized and their photophysical properties (absorption, excitation and luminescence spectra and emission quantum yield) investigated down to 4.2 K. The Eu(tan) 3 bipy complex has its molecular structure experimentally determined using X-ray crystallography and theoretically using the SMLC/AM1 method as well as their electronic singlet and triplet states were calculated, using the INDO/S-CI method with a point charge model to represent the Eu 3+ ion, where two values were adopted, +3.0e and +3.5e, to investigate the imperfect shielding of the 4f shells. The so calculated +3.5e model electronic absorption spectrum and low lying triplet state energies agreed very well with the experimental ones. The emission quantum yield of the Eu 3+ complex is quite low at room temperature, namely 7%, probably due to the too low lying triplet state, 19,050 cm -1 , and increases by a factor of three when the temperature is lowered to 4.2 K. This strong thermal effect indicates the presence of a channel deactivating the main emitting state, what can be due to a LMCT state possibly lying in the same spectral region, as usually found in Eu 3+ compounds.r 2005 Elsevier B.V. All rights reserved.

com o grupo éster do criptato de térbio. A formação do produto foi acompanhada por cromatografia líquida de alta eficiência (CLAE) em 238 nm e 310 nm. A presença de microcistina-LR na molécula marcada foi confirmada através de ensaio com enzima ligada a imunoabsorvente (ELISA) e por reação protéica com ácido bicincônico. O espectro de luminescência do criptato e da molécula conjugada também foram confirmados.A new fluorescent labeled compound of microcystin-LR with terbium cryptate was obtained by initial conjugation of microcystins-LR with aminoethanethiol followed by the reaction with the ester group of terbium cryptate. The product formation was followed by high performance liquid chromatography (HPLC) at 238 nm and 310 nm. The presence of microcystin-LR in the labeled molecule was confirmed by enzyme linked immunosorbent assay ELISA and by protein reaction with bicinhonic acid. Luminescence spectra of cryptate and the conjugated molecule were carried through as well. Keywords: terbium cryptate, microcystin-LR, cyanobacteria IntroductionMicrocystins are a group of stable heptapeptide hepatotoxins produced by freshwater cyanobacteria genera that lower the water quality leading to an increase in the risk of intoxication for animals and humans. Species of genera Microcystis, Anabaena, Aphanizomenon, Planktothrix (Oscillatoria), and Nostoc are frequently described as producers of microcystins. 1 The eutrophication of ponds, rivers and other freshwater ecosystems allows cyanobacteria to flourish, leading to contamination of the water. Microcystins are potent inhibitors of protein phosphatases 1 (PP 1 ) and 2A (PP 2A ), which are regulatory enzymes present in the cytosol of mammalian cells. 3 The general structure of microcystins is composed of cyclo-(D-Ala-X-D-MeAsp-ZAdda-D-Glu-Mdha), where X and Z could be various kinds of L-amino acids; D-MeAsp is D-erythro-β-methylaspartic acid; Mdha is N-methyldehydroalanine; and Adda is the unusual amino acid 2S,3S,8S,9S-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4E,6E-dienoic acid. 4 The most extensively studied form is microcystin-LR that contains L-leucine and L-arginine in the two main variant positions. In the search for more sensitive markers, some chelates of lanthanides had already been obtained and tested in various biological assay models. [25][26][27] Time-resolved fluoroimmunometric assay (TR-FIA) is a method based on the luminescence emission that is measured after a delay has elapsed from a pulsed excitation, enabling the short-lived background fluorescence to be excluded. 28Soini et. al.29 labeled anti-rabbit IgG with europium chelate as a model to detect rabbit IgG for human smooth muscle myosin in a histological section; Bonin et al. 30 used a complex of europium and samarium for the detection of diphteria antitoxins in serum using the ELISA method and Xu et al.31 labeled anti-β-LH and monoclonal anti-β-FSH antibodies with europium and samarium, respectively. The use of luminescent lanthanide as a substitute for labeled enzyme (e.g. horseradish peroxidas...

SYNTHESIS, CHARACTERIZATION AND SPECTROSCOPIC PROPERTIES OF [Ln⊂(bipy) 2 py(CO 2 Et) 2 ] 3+ LANTHANIDE CRYPTATES. This work reports on the synthesis, characterization (infrared and hidrogen nmr spectra) and photophysical properties (luminescence spectra and emission quantum yield) of the lanthanide cryptates [Ln⊂(bipy) 2 py(CO 2 Et) 2 ] 3+ with Ln = Eu 3+ , Tb 3+ or Gd 3+ , which can be applied as efficient Light-Conversion-Molecular-Devices. From emission spectra of [Eu⊂(bipy) 2 py(CO 2 Et) 2 ] 3+ it was possible to assign C 3 symmetry to the metal ion. The spectroscopic studies show a higher emission quantum yield (q=25%) for [Tb⊂(bipy) 2 py(CO 2 Et) 2 ] 3+ in aqueous solution, whereas the europium cryptate presents q=14%. This is justified by a more efficient energy transfer between triplet and emission levels of terbium (T→ 5 D 4).

ResumoMetal-Organic Framework (MOF) é uma rede de coordenação com ligantes orgânicos e estrutura porosa. O objetivo dessa pesquisa foi sintetizar por via eletroquímica a MOF [Cu3(BTC)2(H2O)3]n e aplicá-la como material adsorvente para a remoção de corantes de tecidos nos efluentes. A MOF foi síntizada eletroquimicamente e por via amperométrica, fixando-se o potencial em 12 V durante 17 min, resultando em 73% de rendimento de um sólido azul. O produto final foi usado na sua forma bruta e caracterizado por FTIR e voltametria cíclica. Essa MOF, quando em contato com uma mistura que simulou um efluente de indústria têxtil, permitiu sua descoloração, acompanhada da decantação de um sólido colorido. Essa despigmentação também foi observada através da análise do sobrenadante por espectroscopia UV-Vis. O espectro de FTIR do sólido decantado após a mistura da MOF com o corante, evidenciou a adsorção dos pigmentos da solução pela MOF. Esse resíduo sólido de MOF apresentou-se ambientalmente vantajoso, por ter sido facilmente separado do efluente tratado e por ser regenerável e reutilizável. Isso o diferencia do lodo gerado nos processos de coagulação/floculação tradicionais, que pode ser danoso ao meio ambiente. Palavras-chave:Efluente Têxtil, MOF, Síntese Eletroquímica, Tratamento de efluentes. Adsorption of textile dyes using metal-organic framework [Cu3(BTC)2(H2O)3]n obtained by electrochemical synthesisAbstract Metal-Organic Framework (MOF) is a coordination network with organic binders and porous structure. The objective of this research was to synthesize the MOF of [Cu3(BTC)2(H2O)3]n by electrochemical route and to apply it as adsorbent material for removal of dyes from tissues in effluents. The synthesis of this MOF was given electrochemically via amperometric, setting the potential at 12V for 17 min, resulting in 73% yield of a blue solid. The final product was used in its crude form and characterized by FTIR and cyclic voltammetry. This MOF, when in contact with a mixture that simulates an effluent of the textile industry, allowed its discoloration, accompanied by the decanting of a colored solid. This depigmentation was also observed by analysis of the supernatant by UV-Vis spectroscopy. The FTIR spectrum of the solid decanted after mixing the MOF with the dye showed the adsorption of the pigments from the solution by the MOF. This solid MOF residue was environmentally advantageous because it was easily separated from the treated effluent and being regenerated and reusable. This differentiates it from the sludge generated in traditional coagulation/flocculation process that can be harmful to the environment.

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