454 results on '"Martínez, José I."'
Search Results
202. Titelbild: Fast Prediction of Adsorption Properties for Platinum Nanocatalysts with Generalized Coordination Numbers (Angew. Chem. 32/2014)
- Author
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Calle-Vallejo, Federico, primary, Martínez, José I., additional, García-Lastra, Juan M., additional, Sautet, Philippe, additional, and Loffreda, David, additional
- Published
- 2014
- Full Text
- View/download PDF
203. Cover Picture: Fast Prediction of Adsorption Properties for Platinum Nanocatalysts with Generalized Coordination Numbers (Angew. Chem. Int. Ed. 32/2014)
- Author
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Calle‐Vallejo, Federico, primary, Martínez, José I., additional, García‐Lastra, Juan M., additional, Sautet, Philippe, additional, and Loffreda, David, additional
- Published
- 2014
- Full Text
- View/download PDF
204. Fast Prediction of Adsorption Properties for Platinum Nanocatalysts with Generalized Coordination Numbers
- Author
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Calle-Vallejo, Federico, primary, Martínez, José I., additional, García-Lastra, Juan M., additional, Sautet, Philippe, additional, and Loffreda, David, additional
- Published
- 2014
- Full Text
- View/download PDF
205. Imaging Molecular Orbitals of PTCDA on Graphene on Pt(111): Electronic Structure by STM and First-Principles Calculations
- Author
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Martínez-Galera, Antonio J., primary, Nicoara, Nicoleta, additional, Martínez, José I., additional, Dappe, Yannick J., additional, Ortega, José, additional, and Gómez-Rodríguez, José M., additional
- Published
- 2014
- Full Text
- View/download PDF
206. Detailed mechanical design of the LIPAc beam dump radiological shielding
- Author
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Nomen Escoda, Oriol, Mollá, Joaquin, Sanmartí Cardona, Manel, Martínez, José I., Arranz, Fernando, Iglesias, Daniel, Barrera, German, Brañas, Beatriz, Ogando, Francisco, Nomen Escoda, Oriol, Mollá, Joaquin, Sanmartí Cardona, Manel, Martínez, José I., Arranz, Fernando, Iglesias, Daniel, Barrera, German, Brañas, Beatriz, and Ogando, Francisco more...
- Abstract
The LIPAc is a 9 MeV, D+ linear prototype accelerator for the validation of the IFMIF accelerator design. The high intensity, 125 mA CW beam is stopped in a copper cone involving a high production of neutrons and gamma radiation and activation of its surface. The beam stopper is surrounded by a shielding to attenuate the resulting radiation so that dose rate values comply with the limits at the different zones of the installation. The shielding includes for that purpose polyethylene rings, water tanks and gray cast iron rings. A lead shutter has also been designed to shield the gamma radiation that comes through the beam tube when the linear accelerator is not in operation, in order to allow access inside the building for maintenance tasks. The present work summarizes the detailed mechanical design of the beam dump shielding and the lead shutter taking into account the design constraints, such as working conditions and other external loads, as well as including provisions for dismantling., Peer Reviewed, Postprint (published version) more...
- Published
- 2013
207. Tailored Formation of N-Doped Nanoarchitectures by Diffusion-Controlled on-Surface (Cyclo)Dehydrogenation of Heteroaromatics
- Author
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Ministerio de Ciencia e Innovación (España), Comunidad de Madrid, Czech Science Foundation, Academy of Sciences of the Czech Republic, Pinardi, Anna Lisa, Otero, Gonzalo, Palacio, Irene, Martínez, José I., Sánchez-Sánchez, Carlos, Tello Ruiz, Marta, Rogero, Celia, Cossaro, Albano, Preobrajenski, Alexei, Gómez-Lor, Berta, Jancarik, Andrej, Stará̈, Irena G., Starý, Ivo, López, María Francisca, Méndez, Javier, Martín-Gago, José A., Ministerio de Ciencia e Innovación (España), Comunidad de Madrid, Czech Science Foundation, Academy of Sciences of the Czech Republic, Pinardi, Anna Lisa, Otero, Gonzalo, Palacio, Irene, Martínez, José I., Sánchez-Sánchez, Carlos, Tello Ruiz, Marta, Rogero, Celia, Cossaro, Albano, Preobrajenski, Alexei, Gómez-Lor, Berta, Jancarik, Andrej, Stará̈, Irena G., Starý, Ivo, López, María Francisca, Méndez, Javier, and Martín-Gago, José A. more...
- Abstract
Surface-assisted cyclodehydrogenation and dehydrogenative polymerization of polycyclic (hetero)aromatic hydrocarbons (PAH) are among the most important strategies for bottom-up assembly of new nanostructures from their molecular building blocks. Although diverse compounds have been formed in recent years using this methodology, a limited knowledge on the molecular machinery operating at the nanoscale has prevented a rational control of the reaction outcome. We show that the strength of the PAH–substrate interaction rules the competitive reaction pathways (cyclodehydrogenation versus dehydrogenative polymerization). By controlling the diffusion of N-heteroaromatic precursors, the on-surface dehydrogenation can lead to monomolecular triazafullerenes and diazahexabenzocoronenes (N-doped nanographene), to N-doped oligomeric or polymeric networks, or to carbonaceous monolayers. Governing the on-surface dehydrogenation process is a step forward toward the tailored fabrication of molecular 2D nanoarchitectures distinct from graphene and exhibiting new properties of fundamental and technological interest. more...
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- 2013
208. Chemistry and temperature-assisted dehydrogenation of C60H30 molecules on TiO2(110) surfaces
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Sánchez-Sánchez, Carlos, Martínez, José I., Lanzilotto, Valeria, Biddau, Giulio, Gómez-Lor, Berta, Pérez, Rubén, Floreano, Luca, López, María Francisca, Martín-Gago, José A., Sánchez-Sánchez, Carlos, Martínez, José I., Lanzilotto, Valeria, Biddau, Giulio, Gómez-Lor, Berta, Pérez, Rubén, Floreano, Luca, López, María Francisca, and Martín-Gago, José A. more...
- Abstract
The thermal induced on-surface chemistry of large polycyclic aromatic hydrocarbons (PAHs) deposited on dielectric substrates is very rich and complex. We evidence temperature-assisted (cyclo)dehydrogenation reactions for C 60H30 molecules and the subsequent bottom-up formation of assembled nanostructures, such as nanodomes, on the TiO2(110) surface. To this aim we have deposited, under ultra-high vacuum, a submonolayer coverage of C60H30 and studied, by a combination of experimental techniques (STM, XPS and NEXAFS) and theoretical methods, the different chemical on-surface interaction stages induced by the increasing temperature. We show that room temperature adsorbed molecules exhibit a weak interaction and freely diffuse on the surface, as previously reported for other aromatics. Nevertheless, a slight annealing induces a transition from this (meta)stable configuration into chemisorbed molecules. This adsorbate-surface interaction deforms the C60H30 molecular structure and quenches surface diffusion. Higher annealing temperatures lead to partial dehydrogenation, in which the molecule loses some of the hydrogen atoms and LUMO levels spread in the gap inducing a net total energy gain. Further annealing, up to around 750 K, leads to complete dehydrogenation. At these temperatures the fully dehydrogenated molecules link between them in a bottom-up coupling, forming nanodomes or fullerene-like monodisperse species readily on the dielectric surface. This work opens the door to the use of on-surface chemistry to generate new bottom-up tailored structures directly on high-K dielectric surfaces. © 2013 The Royal Society of Chemistry. more...
- Published
- 2013
209. Number of outer electrons as descriptor for adsorption processes on transition metals and their oxides
- Author
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Calle-Vallejo, Federico, Inoglu, Nilay G., Su, Hai-Yan, Martínez, José I., Man, Isabela C., Koper, Marc T. M., Kitchin, John R., Rossmeisl, Jan, Calle-Vallejo, Federico, Inoglu, Nilay G., Su, Hai-Yan, Martínez, José I., Man, Isabela C., Koper, Marc T. M., Kitchin, John R., and Rossmeisl, Jan more...
- Abstract
The trends in adsorption energies of the intermediates of the oxygen reduction and evolution reactions on transition metals and their oxides are smoothly captured by the number of outer electrons. This unique descriptor permits the construction of predictive adsorption-energy grids and explains the existence of scaling relationships among these compounds. more...
- Published
- 2013
210. Solvent‐Induced Delamination of a Multifunctional Two Dimensional Coordination Polymer (Adv. Mater. 15/2013)
- Author
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Gallego, Almudena, primary, Hermosa, Cristina, additional, Castillo, Oscar, additional, Berlanga, Isadora, additional, Gómez‐García, Carlos J., additional, Mateo‐Martí, Eva, additional, Martínez, José I., additional, Flores, Fernando, additional, Gómez‐Navarro, Cristina, additional, Gómez‐Herrero, Julio, additional, Delgado, Salome, additional, and Zamora, Félix, additional more...
- Published
- 2013
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211. Energy Level Alignment in Organic–Organic Heterojunctions: The TTF/TCNQ Interface
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Beltrán, Juan I., primary, Flores, Fernando, additional, Martínez, José I., additional, and Ortega, José, additional
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- 2013
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212. Number of outer electrons as descriptor for adsorption processes on transition metals and their oxides
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Calle-Vallejo, Federico, primary, Inoglu, Nilay G., additional, Su, Hai-Yan, additional, Martínez, José I., additional, Man, Isabela C., additional, Koper, Marc T. M., additional, Kitchin, John R., additional, and Rossmeisl, Jan, additional more...
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- 2013
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213. Metalation of tetraphenylporphyrin with nickel on a TiO2(110)-1 × 2 surface.
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Wang, Cici, Fan, Qitang, Han, Yong, Martínez, José I., Martín-Gago, José A., Wang, Weijia, Ju, Huanxin, Gottfried, J. Michael, and Zhu, Junfa
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- 2016
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214. Optical absorption spectra of V+4 isomers: One example of first-principles theoretical spectroscopy with time-dependent density functional theory
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Martínez, José I., Castro, Alberto, Rubio, Angel, Alonso, J. A., Martínez, José I., Castro, Alberto, Rubio, Angel, and Alonso, J. A.
- Abstract
We have calculated the optical absorption spectrum of four isomers of the ionized Vanadium tetramer V+4 using the time-dependent density functional theory, with the adiabatic local density approximation for the exchange and correlation potential. The computational scheme is based on a real-time propagation of the time-dependent Kohn-Sham equations. The significantly different spectra of the four isomers permit the identification of the isomer with C2v symmetry as the one predominantly present in the laboratory beams. This assignment is confirmed by the fact that this isomer has the lowest energy. We also report other properties of these charged structures such as static electric dipole polarizabilities, vertical ionization potentials and electron affinities, and densities of electronic states. more...
- Published
- 2006
215. Photoabsorption spectra of Ti8 C12 metallocarbohedrynes: Theoretical spectroscopy within time-dependent density functional theory
- Author
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Martínez, José I., Castro, Alberto, Rubio, Angel, Alonso, J. A., Martínez, José I., Castro, Alberto, Rubio, Angel, and Alonso, J. A.
- Abstract
The photoabsorption spectra of several of the most stable isomers of the Ti8 C12 metallocarbohedryne are calculated using time-dependent density functional theory. Several ground-state magnitudes have been also calculated, such as cohesive energies, electronic gaps between the highest occupied and lowest unoccupied molecular orbitals, and static polarizabilities. Since significant differences are found among the photoabsorption spectra of the different isomers in the low energy region (0-5 eV), we propose the comparison of experimental and the calculated absorption spectra as a tool to elucidate the isomers that appear to form in the experiments. Between 10 and 13 eV all the spectra show a region of high absorption that we identify as due to collective electronic excitations. The existence of this prominent feature explains the occurrence of delayed ionization and delayed ion emission phenomena observed in previous experiments. © 2006 American Institute of Physics. more...
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- 2006
216. First-Principles Structural and Electronic Characterization of Ordered SiO2 Nanowires
- Author
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Martínez, José I., primary, Calle-Vallejo, Federico, additional, Krowne, Clifford M., additional, and Alonso, Julio A., additional
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- 2012
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217. Calculation of the optical spectrum of the Ti8C12 and V8C12 Met-Cars
- Author
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Martínez, José I., Castro, Alberto, Rubio, Angel, Poblet, J. M., Alonso, J. A., Martínez, José I., Castro, Alberto, Rubio, Angel, Poblet, J. M., and Alonso, J. A.
- Abstract
The optical absorption spectrum of the Ti8C12 and V8C12 Met-Cars is calculated using time-dependent density functional theory within a real-space, real-time scheme. Other ground-state quantities are also calculated, such as the ionization potential and the electronic affinity. The broad absorption features of the calculated absorption spectrum are related to experimental results about delayed ionization and delayed ion emission phenomena that have been observed in these structures. more...
- Published
- 2004
218. Back Cover: Simulating the organic-molecule/metal interface TCNQ/Au(111) (Phys. Status Solidi B 9/2011)
- Author
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Martínez, José I., primary, Abad, Enrique, additional, Flores, Fernando, additional, and Ortega, José, additional
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- 2011
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219. Simulating the organic-molecule/metal interface TCNQ/Au(111)
- Author
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Martínez, José I., primary, Abad, Enrique, additional, Flores, Fernando, additional, and Ortega, José, additional
- Published
- 2011
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220. Cover Picture: Universality in Oxygen Evolution Electrocatalysis on Oxide Surfaces (ChemCatChem 7/2011)
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Man, Isabela C., primary, Su, Hai‐Yan, additional, Calle‐Vallejo, Federico, additional, Hansen, Heine A., additional, Martínez, José I., additional, Inoglu, Nilay G., additional, Kitchin, John, additional, Jaramillo, Thomas F., additional, Nørskov, Jens K., additional, and Rossmeisl, Jan, additional more...
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- 2011
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221. Universality in Oxygen Evolution Electrocatalysis on Oxide Surfaces
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Man, Isabela C., primary, Su, Hai‐Yan, additional, Calle‐Vallejo, Federico, additional, Hansen, Heine A., additional, Martínez, José I., additional, Inoglu, Nilay G., additional, Kitchin, John, additional, Jaramillo, Thomas F., additional, Nørskov, Jens K., additional, and Rossmeisl, Jan, additional more...
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- 2011
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222. Trends in Stability of Perovskite Oxides
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Calle-Vallejo, Federico, primary, Martínez, José I., additional, García-Lastra, Juan M., additional, Mogensen, Mogens, additional, and Rossmeisl, Jan, additional
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- 2010
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223. Genetic Algorithm for Boolean minimization in an FPGA cluster
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Pedraza, César, primary, Castillo, Javier, additional, Martínez, José I., additional, Huerta, Pablo, additional, Bosque, Jose L., additional, and Cano, Javier, additional
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- 2010
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224. Scaling Relationships for Adsorption Energies on Transition Metal Oxide, Sulfide, and Nitride Surfaces
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Fernández, Eva M., primary, Moses, Poul G., additional, Toftelund, Anja, additional, Hansen, Heine A., additional, Martínez, José I., additional, Abild-Pedersen, Frank, additional, Kleis, Jesper, additional, Hinnemann, Berit, additional, Rossmeisl, Jan, additional, Bligaard, Thomas, additional, and Nørskov, Jens K., additional more...
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- 2008
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225. Theoretical study of the reactivity of cesium with benzene and graphitic CxHy clusters
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Martínez, José I., primary, López, María J., additional, and Alonso, Julio A., additional
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- 2005
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226. Preparation and Characterization of Inclusion Complex of Norflurazon and β-Cyclodextrin To Improve Herbicide Formulations
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Villaverde, Jaime, primary, Morillo, Esmeralda, additional, Pérez-Martínez, José I., additional, Ginés, Juan M., additional, and Maqueda, Celia, additional
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- 2004
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227. The Reaction of Poly(chlorophosphazene)s with p-Aminophenol − Specific Formation of Aminophosphazenes with Terminal OH Groups and Aryloxyphosphazenes with Terminal NH2 Groups
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Carriedo, Gabino A., primary, Fidalgo Martínez, José. I., additional, García Alonso, F. J., additional, Rodicio González, E., additional, and Presa Soto, A., additional
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- 2002
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228. The Reaction of Poly(chlorophosphazene)s withp-Aminophenol − Specific Formation of Aminophosphazenes with Terminal OH Groups and Aryloxyphosphazenes with Terminal NH2 Groups
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Carriedo, Gabino A., primary, Fidalgo Martínez, José. I., additional, García Alonso, F. J., additional, Rodicio González, E., additional, and Presa Soto, A., additional
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- 2002
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229. Nuclear Magnetic Resonance Investigations of the Inclusion Complexation of Gliclazide with β-Cyclodextrin
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Moyano, José R., primary, Arias-Blanco, María J., additional, Gines, Juan M., additional, Rabasco, Antonio M., additional, Pérez-Martínez, José I., additional, Mor, Marco, additional, and Giordano, Ferdinando, additional more...
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- 1997
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230. Engineering Periodic Dinuclear Lanthanide‐Directed Networks Featuring Tunable Energy Level Alignment and Magnetic Anisotropy by Metal Exchange (Small 22/2022).
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Moreno, Daniel, Parreiras, Sofia O., Urgel, José I., Muñiz‐Cano, Beatriz, Martín‐Fuentes, Cristina, Lauwaet, Koen, Valvidares, Manuel, Valbuena, Miguel A., Gallego, José M., Martínez, José I., Gargiani, Pierluigi, Camarero, Julio, Miranda, Rodolfo, and Écija, David more...
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- 2022
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231. Detailed mechanical design of the LIPAc beam dump radiological shielding.
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Nomen, Oriol, Martínez, José I., Arranz, Fernando, Iglesias, Daniel, Barrera, Germán, Brañas, Beatriz, Ogando, Francisco, Molla, Joaquín, and Sanmartí, Manel
- Subjects
- *
RADIATION shielding , *PROTOTYPES , *POLYETHYLENE , *NEUTRON irradiation , *ACTIVATION energy , *PARTICLE accelerators , *COPPER - Abstract
Abstract: The LIPAc is a 9MeV, D+ linear prototype accelerator for the validation of the IFMIF accelerator design. The high intensity, 125mA CW beam is stopped in a copper cone involving a high production of neutrons and gamma radiation and activation of its surface. The beam stopper is surrounded by a shielding to attenuate the resulting radiation so that dose rate values comply with the limits at the different zones of the installation. The shielding includes for that purpose polyethylene rings, water tanks and gray cast iron rings. A lead shutter has also been designed to shield the gamma radiation that comes through the beam tube when the linear accelerator is not in operation, in order to allow access inside the building for maintenance tasks. The present work summarizes the detailed mechanical design of the beam dump shielding and the lead shutter taking into account the design constraints, such as working conditions and other external loads, as well as including provisions for dismantling. [Copyright &y& Elsevier] more...
- Published
- 2013
- Full Text
- View/download PDF
232. Effect of van der Waals forces on the stacking of coronenes encapsulated in a single-wall carbon nanotube and many-body excitation spectrum
- Author
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Dappe, Yannick J. and Martínez, José I.
- Subjects
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VAN der Waals forces , *PLASTIC embedment of electronic equipment , *SINGLE walled carbon nanotubes , *MANY-body problem , *EXCITATION spectrum , *GEOMETRY - Abstract
Abstract: We investigate the geometry, stability, electronic structure and optical properties of C24H12 coronenes encapsulated in a single-wall (19,0) carbon nanotube. By an adequate combination of advanced electronic-structure techniques, involving weak and van der Waals interaction, as well as many-body effects for establishing electronic properties and excitations, we have accurately characterized this hybrid carbon nanostructure, which arises as a promising candidate for opto-electronic nanodevices. In particular, we show that the structure of the stacked coronenes inside the nanotube is characterized by a rotation of every coronene with respect to its neighbors through van der Waals interaction, which is of paramount importance in these systems. We also suggest a tentative modification of the system for this particular rotation to be observed experimentally. A comparison between the calculated many-body excitation spectrum of the systems involved reveals a pronounced optical red-shift with respect to the coronene-stacking gas-phase. The origin of this red-shift is explained in terms of the confinement of the coronene molecules inside the nanotube, showing an excellent agreement with the available experimental evidence. [Copyright &y& Elsevier] more...
- Published
- 2013
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233. Antiphase Boundaries Accumulation Forming a New C60Decoupled Crystallographic Phase on the Rutile TiO2(110)-(1 × 1) Surface
- Author
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Sánchez-Sánchez, Carlos, Martínez, José I., Lanzilotto, Valeria, Méndez, Javier, Martín-Gago, José A., and López, María F.
- Abstract
C60on the rutile TiO2(110)-(1 × 1) surface is known to present a well-ordered p(5 × 2) surface phase. We have identified another crystallographic phase on this surface characterized by a large unit cell containing four C60molecules. This phase, which exhibits four inequivalent C60adsorption sites with just two different molecular orientations, is herein explained in terms of an accumulation of the so-called antiphase boundaries. Among the a prioriten possible antiphase boundary domains, only three of them can result in possible long-range structures attending to geometrical and energetic considerations. In order to fully characterize the structure and energetics of this new C60/TiO2(110)-(1 × 1) phase, an adequate combination of STM and accurate density functional theory based calculations, including an efficient self-consistent implementation of the vdW interaction, has been used. Results suggest that this new phase is the most stable among all the possible antiphase boundary domains. On the other hand, this work rationalizes and enforces the idea of the prevalence of the intermolecular vdW over the molecule–substrate interactions in this particular organic–inorganic interface, which sets TiO2as an ideal substrate for decoupled systems. more...
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- 2014
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234. On-surface synthesis of metal-organic frameworks: the critical role of the reaction conditions.
- Author
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Ruiz Del Árbol, Nerea, Sánchez-Sánchez, Carlos, Martínez, José I., Rodríguez, Luis, Serrate, David, Verdini, Alberto, Floreano, Luca, Jacobson, Peter, Grill, Leonhard, Martín-Gago, José A., and López, María F. more...
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METAL-organic frameworks , *HONEYCOMB structures , *CHEMICAL species , *COPPER , *ADATOMS , *THERMODYNAMICS - Abstract
Two different metal-organic frameworks with either a honeycomb or Kagome structure were grown on Cu(111) using para-aminophenol molecules and native surface adatoms. Although both frameworks are made up from the same chemical species, they are structurally different emphasizing the critical role being played by the reaction conditions during their growth. This work highlights the importance of the balance between thermodynamics and kinetics in the final structure of surface-supported metal-organic networks. [ABSTRACT FROM AUTHOR] more...
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- 2023
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235. Tuning the Magnetic Anisotropy of Lanthanides on a Metal Substrate by Metal–Organic Coordination (Small 35/2021).
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Parreiras, Sofia O., Moreno, Daniel, Cirera, Borja, Valbuena, Miguel A., Urgel, José I., Paradinas, Markos, Panighel, Mirco, Ajejas, Fernando, Niño, Miguel A., Gallego, José M., Valvidares, Manuel, Gargiani, Pierluigi, Kuch, Wolfgang, Martínez, José I., Mugarza, Aitor, Camarero, Julio, Miranda, Rodolfo, Perna, Paolo, and Écija, David more...
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- 2021
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236. Fluorescence enhancement of fungicide thiabendazole by van der Waals interaction with transition metal dichalcogenide nanosheets for highly specific sensors
- Author
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Blanco, Elías, Martínez, José I., Parra-Alfambra, Ana María, Petit-Domínguez, María Dolores, del Pozo, María, Martín-Gago, José A., Casero, Elena, and Quintana, Carmen
- Subjects
Benzimidazole ,Materials science ,Graphene ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Article ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,chemistry ,Transition metal ,law ,symbols ,Molecule ,General Materials Science ,van der Waals force ,0210 nano-technology ,Thiazole ,HOMO/LUMO - Abstract
Many molecules quench their fluorescence upon adsorption on surfaces. Herein we show that the interaction of thiabendazole, a widespread used fungicide of the benzimidazole family, with nanosheets of transition metal dichalcogenides, particularly of WS2, leads to a significant increase, more than a factor of 5, of the fluorescence yield. This surprising effect is rationalized by DFT calculations and found to be related to the inhibition of the intramolecular rotation between the benzimidazole and thiazole groups due to a bonding rigidization upon interaction with the MoS2 surface. This non-covalent adsorption leads to a redistribution of the molecular LUMO that blocks the non-radiative energy dissipation channel. This unusual behaviour does not operate either for other molecules of the same benzimidazole family or for other 2D materials (graphene or graphene oxide). Moreover, we found that a linear dependence of the emission with the concentration of thiabendazole in solution, which combined with the specificity of the process, allows the development of a highly sensitive and selective method towards thiabendazole determination that can be applied to real river water samples. An excellent detection limit of 2.7 nM, comparable to the best performing reported methods, is obtained with very good accuracy (E r ≤ 6.1%) and repro-ducibility (RSD ≤ 4.1%) in the concentration range assayed. more...
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237. Nuclear magnetic resonance investigations of the inclusion complexation of gliclazide with <TOGGLE>β</TOGGLE>-cyclodextrin
- Author
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Moyano, José R., Arias-Blanco, María J., Gines, Juan M., Rabasco, Antonio M., Pérez-Martínez, José I., Mor, Marco, and Giordano, Ferdinando
- Abstract
The formation of the gliclazideβ-cyclodextrin (GL-β-CD) inclusion compound has been studied in the liquid state by phase solubility techniques and by 1H and 13C NMR spectroscopy. From the initial straight portion of the solubility curve (B
S type), the value of the apparent stability constant (Kc ) was calculated as 1094 M−1. The nuclear magnetic resonance studies confirm that GL yields a complex with β-CD in aqueous medium, which is mainly due to the penetration of the azabicyclooctyl group of GL into the cavity of β-CD. The study of the monodimensional nuclear Overhauser effect (NOE) of the H3 proton of CD has shown that the tolyl group also interacts with CD, but to a lesser extent than the azabicyclooctyl moiety. Finally, the application of the continous variation technique confirmed the 1:2 drug:CD stoichiometry of the complex. more...- Published
- 1997
238. Turn‐On Solid‐State Fluorescent Determination of Zinc Ion by Quinoline‐Based Covalent Organic Framework.
- Author
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García‐Arroyo, Paloma, Gala, Elena, Martínez‐Fernández, Marcos, Salagre, Elena, Martínez, José I., Michel, Enrique G., and Segura, José L.
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ZINC ions , *RING networks , *METAL ions , *AQUEOUS solutions , *ZINC - Abstract
A new quinoline‐based COF (covalent organic framework), obtained by Povarov reaction, containing 2,6‐diisopropylphenyl moieties as substituents over the heterocyclic ring is described for detecting Zn2+ in aqueous solution. The introduction of the mentioned bulky phenyl rings into the network favors an increase of the distance between the reticular sheets and their arrangement, obtaining a new material with an alternating AB type stacking. The new material exhibits good selectivity to detect Zn2+ by fluorescence emission in aqueous solutions up to a concentration of 1.2 × 10−4 m of the metal ion. In order to have a deeper insight into the interaction between the COF and the zinc cation, a thorough spectroscopical, microscopical, and theoretical study is also presented and discussed in this communication. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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239. On‐Surface Synthesis of Organolanthanide Sandwich Complexes.
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Mathialagan, Shanmugasibi K., Parreiras, Sofia O., Tenorio, Maria, Černa, Lenka, Moreno, Daniel, Muñiz‐Cano, Beatriz, Navío, Cristina, Valvidares, Manuel, Valbuena, Miguel A., Urgel, José I., Gargiani, Pierluigi, Miranda, Rodolfo, Camarero, Julio, Martínez, José I., Gallego, José M., and Écija, David more...
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SANDWICH construction (Materials) , *SCANNING tunneling microscopy , *X-ray photoelectron spectroscopy , *TUNNELING spectroscopy , *CIRCULAR dichroism - Abstract
The synthesis of lanthanide‐based organometallic sandwich compounds is very appealing regarding their potential for single‐molecule magnetism. Here, it is exploited by on‐surface synthesis to design unprecedented lanthanide‐directed organometallic sandwich complexes on Au(111). The reported compounds consist of Dy or Er atoms sandwiched between partially deprotonated hexahydroxybenzene molecules, thus introducing a distinct family of homoleptic organometallic sandwiches based on six‐membered ring ligands. Their structural, electronic, and magnetic properties are investigated by scanning tunneling microscopy and spectroscopy, X‐ray absorption spectroscopy, X‐ray linear and circular magnetic dichroism, and X‐ray photoelectron spectroscopy, complemented by density functional theory‐based calculations. Both lanthanide complexes self‐assemble in close‐packed islands featuring a hexagonal lattice. It is unveiled that, despite exhibiting analogous self‐assembly, the erbium‐based species is magnetically isotropic, whereas the dysprosium‐based compound features an in‐plane magnetization. [ABSTRACT FROM AUTHOR] more...
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- 2024
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240. Copper-assisted oxidation of catechols into quinone derivatives†
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Frédéric Chérioux, Johann Coraux, José I. Martínez, Valérie Guisset, José Angel Martín Gago, Estelle Mazaleyrat, José Abad, Ana Cristina Gómez-Herrero, Albano Cossaro, Simone Lisi, Alberto Verdini, Philippe David, Carlos Sánchez-Sánchez, Luca Floreano, Gomez-Herrero, A. C., Sanchez-Sanchez, C., Cherioux, F., Martinez, J. I., Abad, J., Floreano, L., Verdini, A., Cossaro, A., Mazaleyrat, E., Guisset, V., David, P., Lisi, S., Martin Gago, J. A., Coraux, J., Agence Nationale de la Recherche (France), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, Comunidad de Madrid, Centre National de la Recherche Scientifique (France), Consejo Superior de Investigaciones Científicas (España), Martínez, José I., Sánchez Sánchez, Carlos, Martín-Gago, José A., Systèmes hybrides de basse dimensionnalité (HYBRID), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Universidad Politecnica de Cartagena, Laboratorio Nazionale TASC (TASC), Consiglio Nazionale delle Ricerche [Roma] (CNR)-INFM, Epitaxie et couches minces (EpiCM), Martínez, José I. [0000-0002-2086-8603], Sánchez Sánchez, Carlos [0000-0001-8644-3766], and Martín-Gago, José A. [0000-0003-2663-491X] more...
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Semiquinone ,Catechols ,Metal nanoparticles ,02 engineering and technology ,Cathecols ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Redox ,Intermediate product ,chemistry.chemical_compound ,Degenerative diseases ,Molecule ,Catechol ,Quinone derivatives ,[CHIM.ORGA]Chemical Sciences/Organic chemistry ,Substrate (chemistry) ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,3. Good health ,0104 chemical sciences ,Quinone ,Copper-assisted oxidation ,Chemistry ,chemistry ,Intramolecular force ,0210 nano-technology - Abstract
Catechols are ubiquitous substances often acting as antioxidants, thus of importance in a variety of biological processes. The Fenton and Haber–Weiss processes are thought to transform these molecules into aggressive reactive oxygen species (ROS), a source of oxidative stress and possibly inducing degenerative diseases. Here, using model conditions (ultrahigh vacuum and single crystals), we unveil another process capable of converting catechols into ROSs, namely an intramolecular redox reaction catalysed by a Cu surface. We focus on a tri-catechol, the hexahydroxytriphenylene molecule, and show that this antioxidant is thereby transformed into a semiquinone, as an intermediate product, and then into an even stronger oxidant, a quinone, as final product. We argue that the transformations occur via two intramolecular redox reactions: since the Cu surface cannot oxidise the molecules, the starting catechol and the semiquinone forms each are, at the same time, self-oxidised and self-reduced. Thanks to these reactions, the quinone and semiquinone are able to interact with the substrate by readily accepting electrons donated by the substrate. Our combined experimental surface science and ab initio analysis highlights the key role played by metal nanoparticles in the development of degenerative diseases., This work was supported by the French National Research Agency through contract ORGANI'SO (ANR-15-CE09-0017). A. C. G. H. and J. C. thank Laurence Magaud for fruitful discussion about the simulation of the structure of the molecules. F. C. thanks Sarah Benchabane for fruitful discussion. C. S. S., J. I. M. and J. A. M. G. acknowledge financial support from Spanish MINECO (MAT2017-85089-C2-1-R, RYC-2015-17730, RYC-2018-024364-I), European Research Council (ERC) under contract (ERC-2013-SYG-610256 NANOCOSMOS), Comunidad de Madrid via Programa de Investigación Tecnologías 2018 (FOTOART-CM S2018/NMT-4367), and the innovation program under grant agreements 785219 and 881603 (GrapheneCore2 and GrapheneCore3-Graphene-based disruptive technologies, respectively). E. M. acknowledges financial support from Région Rhône Alpes (ARC6 program) and the Labex LANEF. J. C. and J. A. M. G. acknowledges financial support from CNRS and CSIC via the IEA program (PIC2017-FR4/07981), under the ORGAN'X project. more...
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- 2020
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241. Inclusion of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) with β-cyclodextrin by different processing methods
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Ginés, Juan M., Pérez-Martínez, Jose I., Arias, Maria J., Moyano, JoséR., Morillo, Esmeralda, Ruiz-Conde, Antonio, and Sanchez-Soto, Pedro J.
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- 1996
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242. Long tracheobronchial and esophageal rupture after blunt chest trauma: Injury by airway bursting
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Martin de Nicolás, Jose L., Gámez, Antonio P., Cruz, Felipe, Díaz-Hellín, Vicente, Marrón, Carmen, Martínez, Jose I., Gálvez, Ramiro, and Toledo, José
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- 1996
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243. Metal-catalyst-free gas-phase synthesis of long-chain hydrocarbons
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Alexandre Dazzi, Mario Accolla, José A. Martín-Gago, Jesús Eduardo Quintanilla-López, Jesse T. Ault, Lidia Martínez, Stergios Katsanoulis, Gonzalo Santoro, Luis Vázquez, Jérémie Mathurin, Nitzan Shauloff, Pablo Merino, Alvaro Mayoral, Enrique Blázquez-Blázquez, Víctor A. de la Peña O’Shea, Raz Jelinek, Pedro L. de Andrés, José I. Martínez, George Haller, Ferenc Borondics, Gary Ellis, José Cernicharo, Rosa Lebrón-Aguilar, Howard A. Stone, European Research Council, Ministerio de Economía y Competitividad (España), Comunidad de Madrid, Ministerio de Ciencia e Innovación (España), Gobierno de Aragón, National Natural Science Foundation of China, ShanghaiTech University, German Research Foundation, Martínez, Lidia [0000-0002-9370-2962], Merino, Pablo [0000-0002-0267-4020], Santoro, Gonzalo [0000-0003-4751-2209], Martínez, José I. [0000-0002-2086-8603], Katsanoulis, Stergios [0000-0002-1186-5937], Mayoral, Álvaro [0000-0002-5229-2717], Vázquez, Luis [0000-0001-6220-2810], Accolla, Mario [0000-0002-9509-5967], Borondics, Ferenc [0000-0001-9975-4301], Blázquez-Blázquez, Enrique [0000-0003-2488-5635], Lebrón-Aguilar, Rosa [0000-0001-6103-6814], Quintanilla-López, Jesús Eduardo [0000-0003-1863-7408], Jelinek, Raz [0000-0002-0336-1384], Cernicharo, José [0000-0002-3518-2524], Stone, Howard A. [0000-0002-9670-0639], Peña O'Shea, Víctor A. de la [0000-0001-5762-4787], de Andrés Rodríguez, Pedro Luis [0000-0002-9012-2890], Haller, George [0000-0003-1260-877X], Ellis, Gary James [0000-0003-4851-6092], Martín-Gago, José A. [0000-0003-2663-491X], Martínez, Lidia, Merino, Pablo, Santoro, Gonzalo, Martínez, José I., Katsanoulis, Stergios, Mayoral, Álvaro, Vázquez, Luis, Accolla, Mario, Borondics, Ferenc, Blázquez-Blázquez, Enrique, Lebrón-Aguilar, Rosa, Quintanilla-López, Jesús Eduardo, Jelinek, Raz, Cernicharo, José, Stone, Howard A., Peña O'Shea, Víctor A. de la, de Andrés Rodríguez, Pedro Luis, Haller, George, Ellis, Gary James, Martín-Gago, José A., Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Max-Planck-Institut für Festkörperforschung, Max-Planck-Gesellschaft, Instituto de Física Fundamental [Madrid] (IFF), Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ETH Zurich, School of Engineering (Brown Engineering), Brown University, ShanghaiTech University [Shanghai], University of Zaragoza - Universidad de Zaragoza [Zaragoza], Institut de Chimie Physique (ICP), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Instituto de Ciencia y Tecnologia de Polimeros (ICTP-CSIC), Ben-Gurion University of the Negev (BGU), Instituto de Química Física Rocasolano (IQFR), Department of Mechanical and Aerospace Engineering [Princeton] (MAE), Princeton University, Photoactivated Processes Unit IMDEA Energía, and European Project: 610256,EC:FP7:ERC,ERC-2013-SyG,NANOCOSMOS(2014) more...
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Work (thermodynamics) ,Materials science ,carbon-based fuels ,Catalyst synthesis ,Science ,Radical ,General Physics and Astronomy ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Lead (geology) ,alkane-based fuels ,[CHIM]Chemical Sciences ,metal catalysts ,Methylene ,Inert ,Alkane ,chemistry.chemical_classification ,Multidisciplinary ,Catalytic mechanisms ,alkane-based chemicals ,General Chemistry ,021001 nanoscience & nanotechnology ,trap-andrelease mechanism ,3. Good health ,0104 chemical sciences ,carbonaceous nanoparticles ,chemistry ,Chemical engineering ,13. Climate action ,Nanoparticles ,0210 nano-technology ,Carbon - Abstract
8 pags, 4 figs. -- The online version contains supplementary material available at https://doi.org/10.1038/s41467-021-26184-0, Development of sustainable processes for hydrocarbons synthesis is a fundamental challenge in chemistry since these are of unquestionable importance for the production of many essential synthetic chemicals, materials and carbon-based fuels. Current industrial processes rely on non-abundant metal catalysts, temperatures of hundreds of Celsius and pressures of tens of bars. We propose an alternative gas phase process under mild reaction conditions using only atomic carbon, molecular hydrogen and an inert carrier gas. We demonstrate that the presence of CH2 and H radicals leads to efficient C-C chain growth, producing micron-length fibres of unbranched alkanes with an average length distribution between C23-C33. Ab-initio calculations uncover a thermodynamically favourable methylene coupling process on the surface of carbonaceous nanoparticles, which is kinematically facilitated by a trap-and-release mechanism of the reactants and nanoparticles that is confirmed by a steady incompressible flow simulation. This work could lead to future alternative sustainable synthetic routes to critical alkane-based chemicals or fuels., We thank Jose Criado for the artwork schematics of the system, in figures 4 and S1; Funding: We thank the European Research Council for funding support under Synergy grant ERC-2013-SyG, G.A. 610256 (NANOCOSMOS). Also, we acknowledge partial support from the Spanish MINECO through grants PID2020-113142RB-C21, PID2019106315RB-I00, and PID2019-106315RB-I00, EU ERC CoG HyMAP 648319, and from the regional government through project S2018-NMT-4367 (FotoArt-CM). AM acknowledges to the Spanish Ministry of Science (RYC2018-024561-I), to the Regional Government of Aragon (DGA E13_20R), to the National Natural Science Foundation of China (NFSC-21850410448, NSFC-21835002), and to the The Centre for Highresolution Electron Microscopy (ChEM), supported by SPST of ShanghaiTech University under contract No. EM02161943. S.K. and G.H. acknowledge funding from the Turbulent Superstructures Program of the German National Science Foundation (DFG) more...
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- 2021
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244. In silico design of 2D polymers containing truxene-based platforms: insights into their structural and electronic properties
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Marcelo Echeverri, José I. Martínez, M. Carmen Ruiz Delgado, Sergio Gámez-Valenzuela, Berta Gómez-Lor, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Comunidad de Madrid, Universidad de Málaga, Junta de Andalucía, Echeverri, Marcelo [0000-0002-9290-4546], Gómez-Lor, Berta [0000-0002-2995-9624], Martínez, José I. [0000-0002-2086-8603], Echeverri, Marcelo, Gómez-Lor, Berta, and Martínez, José I. more...
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chemistry.chemical_classification ,Materials science ,010405 organic chemistry ,General Chemistry ,Polymer ,Conjugated system ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,chemistry ,Chemical physics ,Phenylene ,Electronic properties ,Monolayer ,Materials Chemistry ,Photocatalysis ,Periodic boundary conditions ,Density functional theory ,2D polymers ,Linker - Abstract
In the present work, we investigate two-dimensional (2D) conjugated polymers based on C3-symmetric truxene-based cores at the density functional theory (DFT) level. In total, 27 different 2D polymers have been exhaustively studied with the aim to explore the impact of the following effects on the electronic and charge-transport properties: (i) the nature of the conjugated platform, going from electron-rich truxene (Tx) and triindole (Tr) units to electron-deficient truxenone (To) cores, (ii) the spacing of the cores with different bridges, i.e., phenylene (Ph) or ethynylene (A) units, (iii) the linker position (2,7,12-substitution in the T2 polymers and 3,8,13-substitution in T3 polymers), and (iv) the increased number of ¿-bridges connecting the cores, from three linkers in T2 and T3 to six linkers in T2,3. To this end, we have carried out a large battery of DFT calculations on fragments extracted from the 2D polymers (dimers and trimers) as well as on the corresponding periodic 2D structures (infinite monolayers and self-assembled monolayers) using periodic boundary conditions. Our results show that simultaneous manipulation of the pore surface size and band-gap engineering together with charge-transport parameters can be achieved in these truxene-based 2D polymers by fine-tuning their structural features. The contributions of this study to the overall understanding of the structure¿electronic property relationships of these semiconducting polymers and its correlation with available experimental work are highlighted. Our results provide interesting guidelines to design novel 2D materials with applications ranging from sensing to photocatalysis or electronics., This work was financially supported by the MINECO (CTQ2016-78557-R) and MICINN (PID2019-104125RB-I00) of Spain. JIM acknowledges financial support from Spanish MINECO (MAT2017-85089-C2-1-R, RYC-2015-17730), Comunidad de Madrid via Programa de Investigación Tecnologías 2018 (FOTOART-CM S2018/NMT-4367), and the innovation program under grant agreements 785219 and 881603 (GrapheneCore2 and GrapheneCore3-Graphene-based disruptive technologies, respectively). The work at the University of Málaga wasfunded by the MICINN (PID2019-110305GB-I00) and by the Junta de Andalucıa (P09-FQM-4708, UMA18-FEDERJA-080). S. G.-V. thanks the MINECO for a FPU predoctoral fellowship (FPU17/04908). Computer resources, technical expertise and assistance provided by the SCBI (Supercomputing and Bioinformatics) centre of the University of Málaga are gratefully acknowledged. more...
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- 2020
245. Scattering of a proton with the Li4 cluster: Non-adiabatic molecular dynamics description based on time-dependent density-functional theory
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Castro, A., Isla, M., Martínez, José I., and Alonso, J.A.
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PROTON scattering , *LITHIUM , *MICROCLUSTERS , *MOLECULAR dynamics , *DENSITY functionals , *QUANTUM electronics , *CHARGE transfer , *IONIZATION energy - Abstract
Abstract: We have employed non-adiabatic molecular dynamics based on time-dependent density-functional theory to characterize the scattering behavior of a proton with the Li4 cluster. This technique assumes a classical approximation for the nuclei, effectively coupled to the quantum electronic system. This time-dependent theoretical framework accounts, by construction, for possible charge transfer and ionization processes, as well as electronic excitations, which may play a role in the non-adiabatic regime. We have varied the incidence angles in order to analyze the possible reaction patterns. The initial proton kinetic energy of 10eV is sufficiently high to induce non-adiabatic effects. For all the incidence angles considered the proton is scattered away, except in one interesting case in which one of the Lithium atoms captures it, forming a LiH molecule. This theoretical formalism proves to be a powerful, effective and predictive tool for the analysis of non-adiabatic processes at the nanoscale. [Copyright &y& Elsevier] more...
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- 2012
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246. Mercury speciation analysis in sea water by solid phase microextraction–gas chromatography–inductively coupled plasma mass spectrometry using ethyl and propyl derivatization. Matrix effects evaluation
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Bravo-Sánchez, Luis R., Ruiz Encinar, Jorge, Fidalgo Martínez, José I., and Sanz-Medel, Alfredo
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CHEMICAL speciation , *MERCURY , *CHROMATOGRAPHIC analysis , *INDUCTIVELY coupled plasma mass spectrometry - Abstract
An approach to the speciation analysis of mercury in sea-water samples at sub-ppt levels by means of the hyphenation of solid phase microextraction to gas chromatography–inductively coupled plasma mass spectrometry was developed. Blank values turned out to be the limiting factor for lower detection limits of inorganic mercury. Thus, all the reagents were thoroughly cleaned using laboratory made microcolumns packed with 8-hydroxyquinoline on TSK gel. Sodium tetrapropylborate (NaBPr4) synthesized for the purpose of derivatization of the mercury species resulted in better analytical performances of the method, probably due to lower mercury contamination, than commercial sodium tetraethylborate (NaBEt4). Detection limits down to a few picogram per liter for both mercury and methylmercury were obtained using NaBPr4. The high salt content of sea-water samples was responsible for strong matrix effects, which were overcome by using standards additions to the samples. The validation of the methodology was carried out by direct comparison of the results for inorganic mercury with those obtained using a flow injection system followed by preconcentration/trapping of the species and its detection by atomic absorption spectrometry. The proposed method was applied to the determination of mercury and methylmercury in coastal sea-water samples from Gijo´n (Asturias, Spain) and results obtained are discussed in the light of the butyltin levels previously determined in the same area. [Copyright &y& Elsevier] more...
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- 2004
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247. Ultra-thin NaCl films as protective layers for graphene
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Luis Vázquez, Michael Foerster, Héctor González-Herrero, José I. Martínez, Koen Lauwaet, Irene Palacio, José A. Martín-Gago, Mar García-Hernández, Lucia Aballe, Francisco Palomares, European Commission, Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Comunidad de Madrid, Ministerio de Ciencia, Innovación y Universidades (España), Consejo Superior de Investigaciones Científicas (España), Palacio, Irene, Lauwaet, Koen, Martínez, José I., Palacio, Irene [0000-0002-3345-4848], Lauwaet, Koen [0000-0003-1024-6779], and Martínez, José I. [0000-0002-2086-8603] more...
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Materials science ,Interfaces ,Intercalation (chemistry) ,02 engineering and technology ,Capping layers ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Article ,law.invention ,Metal ,NaCl ,law ,Microscopy ,General Materials Science ,Cu(111) ,Graphene ,Ultra-thin films ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Characterization (materials science) ,Chemical engineering ,Electron diffraction ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Layer (electronics) - Abstract
The ageing of graphene is an important issue for technological applications. Capping layers are a good way of circumventing this problem. In this work, we propose the use of ultra-thin NaCl films as easilyremovable protective layers. We have carried out a detailed characterization of the NaCl/graphene interface on metal substrates, namely Cu(111) and Ir(111), by means of complementary microscopies, electron diffraction and spectroscopic techniques. Interestingly, we show that NaCl neither interacts in a chemical way with graphene nor intercalates through it. We demonstrate that the NaCl film is stable under ambient conditions, protecting the graphene surface from oxidation. In addition, after removing the protective layer, graphene remains intact., This work has been supported by the EU Graphene Flagship funding (Grant Graphene Core2 785219), the Spanish MINECO (MAT2017-85089-C2-1R, MAT2016-80394-R and RYC-2015-17730) and the EU via the ERC-Synergy Program (Grant ERC-2013-SYG-610256 NANOCOSMOS) and the European Structural Funds via FotoArt-CM project (P2018/NMT-4367)., We acknowledge support of the publication fee by the CSIC Open Access Support Initiative through its Unit of Information Resources for Research (URICI) more...
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- 2019
248. Hydrogen quenches the size effects in carbon clusters
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José I. Martínez, Julio A. Alonso, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Comunidad de Madrid, Junta de Castilla y León, Universidad de Valladolid, European Commission, Consejo Superior de Investigaciones Científicas (España), European Research Council, Martínez, José I. [0000-0002-2086-8603], Alonso, Julio A. [0000-0002-8604-8608], Martínez, José I., and Alonso, Julio A. more...
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Materials science ,Hydrogen ,Grupos de Carbono ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,Hidrógeno ,01 natural sciences ,7. Clean energy ,Article ,Delocalized electron ,Cluster (physics) ,Physics::Atomic and Molecular Clusters ,Molecule ,Physical and Theoretical Chemistry ,Physics::Chemical Physics ,Alkane ,chemistry.chemical_classification ,021001 nanoscience & nanotechnology ,Carbon clusters ,0104 chemical sciences ,Bond length ,chemistry ,Chemical physics ,Ionization energy ,0210 nano-technology ,Interacciones químicas ,Carbon ,Chemical interactions - Abstract
Producción Científica, A characteristic fingerprint of atomic clusters is that their properties can vary in a non-smooth way with the cluster size N. This is illustrated herein by studying the cluster size dependence of several properties of neutral CN and cationic C+N carbon clusters: C–C bond lengths, cluster structure, intrinsic cluster stability, ionization energy, and spatial distribution of the reactivity index for charge exchange with electrophiles. Nonetheless, clusters can lose the size dependence of their properties by interaction with other chemical species, which is rationalized in this study by analyzing carbon clusters fully saturated with hydrogen to form linear alkanes, CNH2N+2. In all cases, the lowest energy structures are zigzagging linear chains, the variations of C–C bond lengths and Image ID:c9cp01114e-t1.gif angles with alkane size are very minor and smooth, the stability function shows practically no structure as a function of the alkane size, the ionization energies just decrease smoothly with alkane size, and the spatial distribution of the reactivity index is analogous and highly delocalized in all the alkanes. In summary, the interaction of carbon clusters with hydrogen to form alkanes quenches all the size-dependent features that the carbon clusters originally owned. The arrival at the quenching of the size effects follows an involved path. In each CNHn family with fixed N, the values of the properties of the molecules like the ionization potential, the electron affinity, and others show sizable oscillations as the number of hydrogen atoms grows from the pure carbon cluster to the alkane., Ministerio de Economía, Industria y Competitividad ( grants MAT2017-85089-C2-1-R / RYC-2015-17730), Comunidad de Madrid (FotoArt-CM Project P2018/NMT-4367), Junta de Castilla y León (Grant VA021G18), Universidad de Valladolid (GIR Grupo de Física de Nanoestructuras),y Unión Europea mediante el programa ERC-Synergy (Grant ERC-2013-SYG-610256 Nanocosmos) more...
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- 2019
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249. A Trapezoidal Octacyanoquinoid Acceptor Forms Solution and Surface Products by Antiparallel Shape Fitting with Conformational Dipole Momentum Switch.
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Medina Rivero, Samara, Urieta‐Mora, Javier, Molina‐Ontoria, Agustín, Martín‐Fuentes, Cristina, Urgel, José I., Zubiria‐Ulacia, Maria, Lloveras, Vega, Casanova, David, Martínez, José I., Veciana, Jaume, Écija, David, Martín, Nazario, and Casado, Juan more...
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MOMENTUM transfer , *SCANNING tunneling microscopy , *CHARGE transfer , *ELECTROCHEMISTRY - Abstract
A new compound (1) formed by two antiparallelly disposed tetracyano thienoquinoidal units has been synthesized and studied by electrochemistry, UV/Vis‐NIR, IR, EPR, and transient spectroscopy. Self‐assembly of 1 on a Au(111) surface has been investigated by scanning tunneling microscopy. Experiments have been rationalized by quantum chemical calculations. 1 exhibits a unique charge distribution in its anionic form, with a gradient of charge yielding a neat molecular in‐plane electric dipole momentum, which transforms out‐of‐plane after surface deposition due to twisted→folded conformational change and to partial charge transfer from Au(111). Intermolecular van der Waals interactions and antiparallel trapezoidal shape fitting lead to the formation of an optimal dense on Au(111) two‐dimensional assembly of 1. [ABSTRACT FROM AUTHOR] more...
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- 2021
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250. Smart composite films of nanometric thickness based on copper-iodine coordination polymers. Toward sensors
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Ulises R. Rodríguez-Mendoza, Javier González-Platas, Félix Zamora, Javier Conesa-Egea, Carlos J. Gómez-García, Vanesa Fernández-Moreira, José I. Martínez, Noemí Nogal, Pilar Amo-Ochoa, Salomé Delgado, Ministerio de Economía y Competitividad (España), European Research Council, European Commission, Martínez, José I., González-Platas, Javier, Gómez-García, Carlos J., Zamora, Félix, Amo-Ochoa, Pilar, Martínez, José I. [0000-0002-2086-8603], González-Platas, Javier [0000-0003-3339-2998], Gómez-García, Carlos J. [0000-0002-0015-577X], Zamora, Félix [0000-0001-7529-5120], Amo-Ochoa, Pilar [0000-0002-1952-1020], and UAM. Departamento de Química Inorgánica more...
- Subjects
Materials science ,Fabrication ,Polymers ,Thin films ,Composite number ,Supramolecular chemistry ,Nanocomposite films ,02 engineering and technology ,Optoelectronic devices ,010402 general chemistry ,01 natural sciences ,Nanomaterials ,chemistry.chemical_classification ,Film thickness ,Chains ,Nanostructured materials ,Química ,General Chemistry ,Polymer ,Binary alloys ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemistry ,chemistry ,Chemical engineering ,Nanofiber ,Nanometre ,Film preparation ,0210 nano-technology ,Coordination reactions ,Nanofibres ,Copper ,Mechanoluminescence ,Iodine - Abstract
One-pot reactions between CuI and methyl or methyl 2-amino-isonicotinate give rise to the formation of two coordination polymers (CPs) based on double zig-zag Cu2I2 chains. The presence of a NH2 group in the isonicotinate ligand produces different supramolecular interactions affecting the Cu-Cu distances and symmetry of the Cu2I2 chains. These structural variations significantly modulate their physical properties. Thus, both CPs are semiconductors and also show reversible thermo/mechanoluminescence. X-ray diffraction studies carried out under different temperature and pressure conditions in combination with theoretical calculations have been used to rationalize the multi-stimuli-responsive properties. Importantly, a bottom-up procedure based on fast precipitation leads to nanofibers of both CPs. The dimensions of these nanofibres enable the preparation of thermo/mechanochromic film composites with polyvinylidene difluoride. These films are tens of nanometers in thickness while being centimeters in length, representing smaller thicknesses so far reported for thin-film composites. This nanomaterial integration of CPs could represent a source of alternative nanomaterials for opto-electronic device fabrication., The authors thank financial support from the Spanish Ministerio de Economía y Competitividad (MAT2016-77608-C3-1-P, MAT2016-75883-C2-2-P, MAT2010-20843-C02-01, MAT2016- 75586-C4-4-P, CTQ2016-75816-C2-1P). J. I. M. acknowledges the financial support by the “Ramón y Cajal” Program of MINECO (Grant RYC-2015-17730) and the EU via the ERCSynergy Program (Grant ERC-2013-SYG-610256 NANOCOSMOS). J. C. E. acknowledges the financial support by the “FPI-MINECO” Program of MINECO (Grant BES-2015-071534). more...
- Published
- 2018
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