Encontrados 8 documentos, a visualizar página 1 de 1
Synthesis and photophysical properties of dansyl-based polyamine ligands and th...
Parola, A. Jorge; Lima, João Carlos; Pina, Fernando; Pina, João; Melo, João Seixas de; Soriano, Conxa; García-España, Enrique; Aucejo, RicardoThe synthesis, potentiometric studies and photophysical properties of two new polyamine ligands (L1 and L2) possessing the dansyl chromophore were studied in aqueous 0.15 M NaCl. The compounds show the absorption and emissions bands characteristic of the dansylamide fluorophore and both present intramolecular excited state proton transfer at intermediate pH ranges. One of the ligands (L2) strongly coordinates Z...
Spectroscopy and Coordination Chemistry of a New Bisnaphthalene−Bisphenanthroli...
Pina, João; Melo, J. Seixas de; Pina, Fernando; Lodeiro, Carlos; Lima, J. C.; Parola, A. Jorge; Soriano, Conxa; Paz Clares, M.; Albelda, M. TeresaA new fluorescent macrocyclic structure (L1) bearing two naphthalene units at both ends of a cyclic polyaminic chain containing two phenanthroline units was investigated with potentiometric and fluorescence (steady-state and time-resolved) techniques. The fluorescence emission spectra show the simultaneous presence of three bands: a short wavelength emission band (naphthalene monomer), a middle emission band (...
A New ZnIITweezer Pyridine-Naphthalene System - An Off-On-Off System Working in...
Aucejo, Ricardo; Alarcón, Javier; García-España, Enrique; Llinares, José M.; Marchin, Katherine L.; Soriano, Conxa; Lodeiro, CarlosThe synthesis, protonation behaviour and Zn2+ coordination chemistry of a new photoactive polyamine exhibiting ldquooff-on-offrdquo fluorescence is presented. Addition of Zn2+ reduces the width of the fluorescence window, which is centred around physiological pH, and sharply enhances the emission intensity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) ; http://dx.doi.org/10.1002/ejic.2...
Synthesis and H+, Cu2+, and Zn2+ Coordination Behavior of a Bis(fluorophoric) B...
Clares, M. Paz; Aguilar, Juan; Aucejo, Ricardo; Lodeiro, Carlos; Albelda, M. Teresa; Pina, Fernando; Lima, J. C.; Parola, A. Jorge; Pina, JoãoThe synthesis, protonation behavior, and Cu2+ and Zn2+ coordination chemistry of the novel bibrachial aza lariat ether (naphthalen-1-ylmethyl)[2-(20-2-[(naphthalen-1-ylmethyl)amino]ethyl-3,6,9,17,20,23,29,30-octaazatricyclo[23.3.1.1*11,15*]triaconta-1(29),11(30),12,14,25,27-hexaen-6-yl)ethyl]amine (L) are discussed. The macrocycle, which has two aminoethyl naphthyl moieties symmetrically appended to a 2:2 azapy...
Intramolecular Excimer Formation in a Tripodal Polyamine Receptor Containing Th...
Albelda, M. Teresa; García-España, Enrique; Gil, Laura; Lima, João C.; Lodeiro, Carlos; Melo, J. Seixas de; Melo, M. João; Parola, A. JorgeA comprehensive investigation on the energetics and dynamics of a new fluorescent sensor constituted by a tripodal polyamine receptor containing three naphthalene fluorophores, compound L, is reported. The influence of external factors such as the solvent, hydrogen ion concentration, and temperature in the photophysics of the sensor is discussed. The temperature dependence of monomer/excimer interconversion of ...
Energetics and Dynamics of Naphthalene Polyaminic Derivatives. Influence of Str...
Melo, J. Seixas de; Pina, J.; Pina, F.; Lodeiro, C.; Parola, A. J.; Lima, J. C.; Teresa Albelda, M.; Paz Clares, M.; Garcia-España, EnriqueTwo new fluorescent macrocyclic structures bearing two naphthalene (Np) units at both ends of a cyclic polyaminic chain were investigated with potentiometric, fluorescence (steady-state and time-resolved) and laser flash photolysis techniques. The fluorescence emission studies show the presence of an excimer species whose formation depends on the protonation state of the polyamine chains implying the existence ...
Switching from intramolecular energy transfer to intramolecular electron transf...
Albelda, M. Teresa; Díaz, Pilar; García-España, Enrique; Lima, João C.; Lodeiro, Carlos; Seixas de Melo, J.; Jorge Parola, A.; Pina, Fernandohttp://www.sciencedirect.com/science/article/B6TFN-44SKJK4-4/1/7cd5958d3acd1757d2b3a88517f1d557
Long Range Electron Transfer Quenching in Polyamine Chains Bearing a Terminal N...
Pina, Fernando; Lima, J. C.; Lodeiro, Carlos; Melo, J. Seixas de; Díaz, Pilar; Teresa Albelda, M.; García-España, EnriqueThe fluorescence emission of a naphthalene unit attached to a polyamine chain is quenched by intramolecular electron transfer from the deprotonated amines to the excited fluorophore. Measurements of the respective quenching rate constants as a function of the distance, reveal an exponential dependence with β = 0.45 Å-1. Identical measurements carried out in deuterated water have shown a similar dependence with ...
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