Lewis Base Behavior of Bridging Nitrido Ligands of Titanium Polynuclear Complexes

The Lewis base behavior of mu(3)-nitrido ligands of the polynuclear titanium complexes [{Ti(eta(5)-C(5)Me(5))(mu-NH)}(3)(mu(3)-N)] (1) and [{Ti(eta(5)-C(5)Me(5))}(4)-(mu(3)-N)(4)] (2) to MX Lewis acids has been observed for the first time. Complex 1 entraps one equivalent of copper(I) halide or copper(I) trifluorornethanesulfonate through the basal NH imido groups to give cube-type adducts [XCu{(mu(3)-NH)(3)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}] (X=Cl (3), Br (4), I (5), OSO(2)CF(3) (6)). However, the treatment of 1 with an excess (>= 2 equiv) of copper reagents afforded complexes [XCu{(mu(3)-NH)(3)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(4)-N)(CuX)}] (X=Cl (7), Br (8), I (9) OSO(2)CF(3) (10)) by incorporation of an additional CuX fragment Lit the mu(3)-N nitrido apical group. Similarly, the tetranuclear cube-type nitrido derivative 2 is capable of incorporating one, two, or up to three CuX units at the mu(3)-N ligands to give complexes [{Ti(eta(5)-C(5)Me(5))}(4)(mu(3)-N)(4-n)-{(mu(4)-N)CuX}(n)] (X=Br (11), n=1; X=Cl (12) n=2; X=OSO(2)CF(3) (13), n=3). Compound 2 also reacts with silver(I) trifluoromethanesulfortate (>= 1 equiv) to give the adduct [{Ti(eta(5)-C(5)Me(5))}(4)(mu(3)-N)(3){(mu(4)-N)AgOSO(2)CF(3)}] (14). X-ray crystal structure determinations have been performed for complexes 8-13. Density functional theory calculations have been carried out to understand the nature and strength of the interactions of [{Ti(eta(5)-C(5)H(5))(mu-NH)}(3)(mu(3)-N)] (1') and [{Ti(eta(5)-C(5)H(5))}(4)-(mu(3)-N)(4)] (2') model complexes with copper and silver MX fragments. Although coordination through the three basal NH imido groups is thermodynamically preferred in the case of V, in both complexes the mu(3)-nitrido groups act as two-electron donor Lewis bases to the appropriate Lewis acids.MINISTERIO DE EDUCACIÓN Y CIENCIA, COMUNIDAD DE MADRID, UNIVERSIDAD DE ALCALÁ, GENERALITAT DE CATALUNY

An Ultra‐Long‐Lived Triplet Excited State in Water at Room Temperature: Insights on the Molecular Design of Tridecafullerenes

Suitably engineered molecular systems exhibiting triplet excited states with very long lifetimes are important for high-end applications in nonlinear optics, photocatalysis, or biomedicine. We report the finding of an ultra-long-lived triplet state with a mean lifetime of 93 ms in an aqueous phase at room temperature, measured for a globular tridecafullerene with a highly compact glycodendrimeric structure. A series of three tridecafullerenes bearing different glycodendrons and spacers to the C60 units have been synthesized and characterized. UV/Vis spectra and DLS experiments confirm their aggregation in water. Steady-state and time-resolved fluorescence experiments suggest a different degree of inner solvation of the multifullerenes depending on their molecular design. Efficient quenching of the triplet states by O2 but not by waterborne azide anions has been observed. Molecular modelling reveals dissimilar access of the aqueous phase to the internal structure of the tridecafullerenes, differently shielded by the glycodendrimeric shell

Compartir ideas, la universidad va al instituto. Análisis de la primera edición de un proyecto de aprendizaje servicio transversal a la Universidad de Barcelona

Esta comunicación presenta las principales claves de análisis y evaluación de la 1a edición del proyecto Compartir Ideas. La Universidad va al instituto. Este es un proyecto de aprendizaje servicio transversal que consiste en un ciclo de conferencias-taller impartidas por estudiantes de la UB sobre temes de interés general relacionados con sus estudios. El objetivo es compartir conocimientos y conversar sobre un tema que la universidad trabaja y que será relevante para la formación del alumnado de secundaria.El proyecto cuenta con el apoyo del Vicerectorado de Política Docente y Lingüística de la Universitat de Barcelona

Palaeogene-Neogene/Present Day (?) Growth Folding in the Bahamian Foreland of the Cuban Fold and Thrust Belt

The Santaren Anticline constitutes the frontal termination of the Cuban fold and thrust belt within the Bahamian foreland. New well and seismic data allow us to constrain in detail the evolution of this anticline. Pre-growth and syntectonic (partly post-tectonic?) units, separated by a major unconformity, are associated with the Santaren Anticline. Their geometrical features are consistent with a detachment fold. The precise age of the beginning of fold growth remains unknown. However, the complete record of well-dated syntectonic sediments documents its kinematic evolution from Mid-Eocene to Pliocene/present day, and reveals an approximately constant and very slow growth rate from Early Miocene to Pliocene/present day. The timing of evolution of the Santaren Anticline is not consistent with previous models that postulate that deformation associated with the Cuban fold and thrust belt ended in the Eocene. Our data suggest that the most external part of the Cuban fold and thrust belt was still being deformed under a compressional regime during the late Palaeogene, Neogene and probably during the Quaternary. We propose that this folding may result from compressive stresses transmitted approximately 400 km northwards from the actual plate boundary, as a result of slow convergence between the N and S American plates

Tuning Photoinduced Electron Transfer in POM‐bodipy Hybrids by Controlling the Environment, Experiment and Theory.

International audienceThe optical and electrochemical properties of a series of polyoxometalates (POMs) oxoclusters decorated with two bodipy (boron-dipyrromethene) light harvesting units were examined. We evaluated in this polyanionic donor-acceptor system the effect of the solvent and associated counterions on the intramolecular photoinduced electron transfer. Our results show that both solvents and counterions have a major impact upon the energy of the charge transfer state by modifying the solvation shell around the POM. This leads to a significantly shorter charge separation time in case of smaller counterion and slower charge recombination in a less polar solvent. We rationalize these results in terms of Marcus theory and show that solvent and counterion both affect the driving force for photoinduced electron transfer and the reorganization energy. This was corroborated with theoretical investigations combining DFT and molecular dynamics simulations

Ergonómia az építőipar szolgálatában a Tam-Bau Kft.-nél

We conducted a systematic review and individual participant data meta-analysis to explore the role of C-reactive protein (CRP) in early detection or prediction of post-stroke infections. CRP, an acute-phase reactant binds to the phosphocholine expressed on the surface of dead or dying cells and some bacteria, thereby activating complement and promoting phagocytosis by macrophages. We searched PubMed up to May-2015 for studies measuring CRP in stroke and evaluating post-stroke infections. Individual participants' data were merged into a single database. CRP levels were standardized and divided into quartiles. Factors independently associated with post-stroke infections were determined by logistic regression analysis and the additional predictive value of CRP was assessed by comparing areas under receiver operating characteristic curves and integrated discrimination improvement index. Data from seven studies including 699 patients were obtained. Standardized CRP levels were higher in patients with post-stroke infections beyond 24 h. Standardized CRP levels in the fourth quartile were independently associated with infection in two different logistic regression models, model 1 [stroke severity and dysphagia, odds ratio = 9.70 (3.10-30.41)] and model 2 [age, sex, and stroke severity, odds ratio = 3.21 (1.93-5.32)]. Addition of CRP improved discrimination in both models [integrated discrimination improvement = 9.83% (0.89-18.77) and 5.31% (2.83-7.79), respectively], but accuracy was only improved for model 1 (area under the curve 0.806-0.874, p = 0.036). In this study, CRP was independently associated with development of post-stroke infections, with the optimal time-window for measurement at 24-48 h. However, its additional predictive value is moderate over clinical information. Combination with other biomarkers in a panel seems a promising strategy for future studies

Compartir ideas, la universidad va al instituto. Análisis de la primera edición de un proyecto de aprendizaje servicio transversal a la Universidad de Barcelona

Esta comunicación presenta las principales claves de análisis y evaluación de la 1a edición del proyecto Compartir Ideas. La Universidad va al instituto. Este es un proyecto de aprendizaje servicio transversal que consiste en un ciclo de conferencias-taller impartidas por estudiantes de la UB sobre temes de interés general relacionados con sus estudios. El objetivo es compartir conocimientos y conversar sobre un tema que la universidad trabaja y que será relevante para la formación del alumnado de secundaria.El proyecto cuenta con el apoyo del Vicerectorado de Política Docente y Lingüística de la Universitat de Barcelona