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Density functional theory study of the oxoperoxo vanadium(V) complexes of glyco...
Justino, Licínia L. G.; Ramos, M. Luísa; Kaupp, Martin; Burrows, Hugh D.; Fiolhais, Carlos; Gil, Victor M. S.The DFT B3LYP/SBKJC method has been used to calculate the gas-phase optimized geometries of the glycolate oxoperoxo vanadium(V) complexes [V2O2(OO)2(gly)2]2-, [V2O3(OO)(gly)2]2- and [VO(OO)(gly)(H2O)]-. The 51V, 17O, 13C and 1H chemical shifts have been calculated for the theoretical geometries in all-electron DFT calculations at the UDFT-IGLO-PW91 level and have been subsequently compared with the experimental...
Conformational Studies of Poly(9,9-dialkylfluorene)s in Solution Using NMR Spec...
Justino, Licínia L. G.; Ramos, M. Luísa; Abreu, Paulo E.; Carvalho, Rui A.; Sobral, Abilio J. F. N.; Scherf, Ullrich; Burrows, Hugh D.Relationships have been obtained between intermonomer torsional angle and NMR chemical shifts (1H and 13C) for isolated chains of two of the most important poly(9,9-dialkylfluorenes), poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6) and the copolymer poly(9,9-dioctylfluorene-co-[2,1,3]benzothiadiazole-4,7-diyl) (F8BT), using DFT calculations. The correlations provide a model for NMR spectral data interpreta...
Density functional theory study of the oxoperoxo vanadium(V) complexes of glyco...
Justino, Licínia L. G.; Ramos, M. Luísa; Kaupp, Martin; Burrows, Hugh D.; Fiolhais, Carlos; Gil, Victor M. S.The DFT B3LYP/SBKJC method has been used to calculate the gas-phase optimized geometries of the glycolate oxoperoxo vanadium(V) complexes [V2O2(OO)2(gly)2]2-, [V2O3(OO)(gly)2]2- and [VO(OO)(gly)(H2O)]-. The 51V, 17O, 13C and 1H chemical shifts have been calculated for the theoretical geometries in all-electron DFT calculations at the UDFT-IGLO-PW91 level and have been subsequently compared with the experimental...
Using Lanthanides as Probes for Polyelectrolyte-Metal Ion Interactions. Hydrati...
Costa, Diana; Ramos, M. Luísa; Burrows, Hugh D.; Tapia, M. José; Miguel, Maria da Graçahttp://www.sciencedirect.com/science/article/B6TFM-4SWFNW8-1/1/aadd2972e76576ca7bf5c347abd5a683
Oxoperoxo Vanadium(V) Complexes of l-Lactic Acid: Density Functional Theory Stu...
Justino, Licínia L. G.; Ramos, M. Luísa; Nogueira, Fernando; Sobral, Abilio J. F. N.; Geraldes, Carlos F. G. C.; Kaupp, Martin; Burrows, Hugh D.Various combinations of density functionals and pseudopotentials with associated valence basis-sets are compared for reproducing the known solid-state structure of [V2O2(OO)2l-lact2]2−cis. Gas-phase optimizations at the B3LYP/SBKJC level have been found to provide a structure that is close to that seen in the solid state by X-ray diffraction. Although this may result in part from error compensation, this optimi...
Oxoperoxo Vanadium(V) Complexes of l-Lactic Acid: Density Functional Theory Stu...
Justino, Licínia L. G.; Ramos, M. Luísa; Nogueira, Fernando; Sobral, Abilio J. F. N.; Geraldes, Carlos F. G. C.; Kaupp, Martin; Burrows, Hugh D.Various combinations of density functionals and pseudopotentials with associated valence basis-sets are compared for reproducing the known solid-state structure of [V2O2(OO)2l-lact2]2−cis. Gas-phase optimizations at the B3LYP/SBKJC level have been found to provide a structure that is close to that seen in the solid state by X-ray diffraction. Although this may result in part from error compensation, this optimi...
Synthesis of flexible dimeric meso-tetrakis-porphyrins
Sobral, Abilio J.F.N.; Melo, Susana M.; Ramos, M. Luísa; Teixeira, Raquel; Andrade, Susana M.; Costa, Silvia M.B.Monofunctionalisation of meso-tetrakis-porphyrins through introduction of a carboxylic group in the meso position of the phenyl group confers the necessary characteristics to anchor them through stable amide bonds to functionalised supports or to molecules. In this Letter we describe the synthesis, characterisation and photophysical evaluation of such a functionalised flexible dimeric porphyrin, bis-(meso-tetra...
Interactions of vanadates with carbohydrates in aqueous solutions
Ribeiro, Ana C. F.; Valente, Artur J. M.; Lobo, Victor M. M.; Azevedo, Eduarda F. G.; Amado, Ana M.; Costa, A. M. Amorim da; Ramos, M. LuísaThe interaction between the vanadate ion (VO3-, i.e. vanadium (V)) and the carbohydrates sucrose, glucose and fructose has been studied in aqueous solutions (pH [approximate]6, 298.15 K) using measurements of diffusion coefficients, electrical conductivity, Raman and multinuclear NMR spectroscopy. With sucrose and glucose, indications of hydrolysis of the anion in the absence of the sugars came from a decrease ...
A multinuclear NMR study of the complexation of W(VI) with meso-2,3-dimercaptos...
Caldeira, M. Madalena; Ramos, M. Luísa; Pereira, Gilberto G.; Gil, Victor M. S.Meso-2,3-dimercaptosuccinic acid (DMSA), which is used as an antidote for heavy metal poisoning and in complexes of 99mTc for diagnostic purposes, forms several complexes with tungsten(VI) in aqueous solutions, as found by 1H, 13C, 17O and 183W NMR spectroscopy. In the pH range ~4-7, there are four complexes in which the acid acts as a bidentate ligand through one carboxyl group and the adjacent sulfhydryl grou...
Peroxovanadium(V) complexes of glycolic acid as studied by NMR spectroscopy
Justino, Licínia L. G.; Ramos, M. Luísa; Caldeira, M. Madalena; Gil, Victor M. S.Multinuclear (1H, 13C, 17O, 51V) 1D and 2D NMR spectroscopy has been used to characterize the peroxovanadium(V) complexes of glycolic acid in aqueous solution. One 2:2:2 (metal:ligand:peroxo) complex, together with a 1:1:1 and a 2:2:1 species, are found in the pH range 1-7. The 2:2:2 complex is a monoperoxo (one peroxide unit per vanadium atom) dinuclear species having a V2O3 4+ seven-coordinated metal centre. ...
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