Donor and acceptor molecules on metal surfaces: supramolecular self-assembly, metal-organic coordination networks, and charge-transfer complexes

This thesis presents a dissertation on supramolecular self-assembly, coordination networks and charge transfer complexes of four molecules: Dicyanop- quinonediimine (DCNQI), Tetracyanoethylene (TCNE), Tetracyanoquinodimethane (TCNQ) and Tetrathiafulvalene (TTF) at a noble metal surface. Different systems were analyzed by variable temperature scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and the results were compared with theoretical within the density functional theory (DFT). In the first part of this thesis, the adsorption of the individual molecules (TCNE, TCNQ, and TTF) on a Ag(111) surface was studied. The growth of TCNE on Ag(111) results in the formation of two different Ag-TCNE coordination networks, depending on the substrate temperature, where the silver adatoms originate from the step etching of the silver substrate. According to DFT calculations and in agreement with XPS measurements, the TCNE molecules are negatively charged ( 1 e), taking charge from the substrate and from the silver adatom (the charge on the silver adatoms is 0.45 e). The adsorption of TCNQ on Ag(111) shows the formation of three different phases, where the molecules are bonded together by hydrogen bonds, but with a strong influence of the interaction of the cyano groups with the silver substrate. Actually, in one of the phases the participation of silver adatoms cannot be completely ruled out. There is also a strong charge transfer from the silver to the TCNQ molecule ( 1 e). On the other hand, for a bilayer of TCNQ molecules on Ag(111), the second layer is much more decoupled from the substrate, and the self-assembly is driven exclusively by the formation of hydrogen bonds between the molecules, in a similar behavior to that reported on graphene and Au(111) substrates. The adsorption of the electron donor TTF on Ag(111) was studied, after room temperature deposition. No isolated or islands could be imaged due to a high molecular diffusivity. Annealing the sample at 350 K results in the formation of well-ordered island where the molecules are slightly tilted with respect to the surface. DFT calculations and XPS measurements show that in this case the charge transfer, although very small ( 0:1 e), takes place in the opposite direction, the molecule remaining positively charged In the second part of the thesis, mixtures of donor/acceptor molecules (TCNQ-TTF, TCNE-TTF) have been studied on a Ag(111) substrate. The metal surface allows us to expands the variety of such Donor-Acceptor (DA) networks. We show that these systems exhibit various structural phases, depending on the stoichiometry, each leading to different levels of charge transfer. In particular, both TCNE and TCNQ, both being strong electron acceptors, hold in every case a negative charge close to 1 e. On the contrary, the charge on the TTF molecules, being positive, seems to increase with the TCNQ content. Thus by controlling the stoichiometry ratio in these complexes, we can tune both the structural and the electronic properties (for example, the work-function) of a D-A system. Finally, in the last part of the thesis on the temperature controlled irreversible transition between the two isomeric forms (trans and cis) of the strong electron acceptor DCNQI, both on Cu(100) and Ag(111) surfaces is reported. The experiments and DFT calculations show that the isomerization barrier is lower than in gas phase or solution due to the fact that charge transfer from the substrate has modified the bond configuration of the molecule. In addition, an Fe-DCNQI coordination network was studied by mixing Fe atoms and DCQNI molecules on Ag(111). After annealing at 380 K, one-dimensional (1-D) network has been observed where one Fe atom is connected to 4 DCNQI, forming chains that assemble together by hydrogen bonds. The electronic structure of this network reveals that the iron atom changes from the metallic state to the oxidized state. In summary, since charge transfer at the metal organic interface plays an important role in the efficiency of many organic optoelectronic devices, we have studied the effect of charge transfer in model donor, acceptor and donor-acceptor systems on a Ag(111), Cu(100) and Au(111).Esta tesis presenta una disertación sobre autoensamblados supramoleculares, redes de coordinación y complejos de transferencia de carga de cuatro moléculas: Dicyano-p-quinonediimine (DCNQI) , Tetracyanoethylene (TCNE), Tetracyanoquinodimethane (TCNQ) and Tetrathiafulvalene (TTF) en superficies de metales nobles. Diferentes sistemas fueron analizados mediante un microcopio de efecto túnel de temperatura variable (STM), espectroscopía de fotoelectrones emitidos por rayos X (XPS) y los resultados fueron comparados con cálculos teóricos mediante la teoría del funcional de la densidad. En la primera parte de esta tesis, se ha estudiado la adsorción de moléculas individuales (TCNE, TCNQ y TTF) sobre la superficie de Ag(111). El crecimiento del TCNE sobre Ag(111) resulta en la formación de dos redes de coordinación diferentes Ag-TCNE, dependiendo de la temperatura del substrato, donde los adátomos se originan desde el escalón atacado del substrato de plata. Según los cálculos de DFT y en acuerdo con las medidas de XPS, las moléculas de TCNE están negativamente cargadas ( 1 e), cogiendo carga del substrato y de los adátomos de plata (la carga sobre los adátomos de plata es de 0.45 e). La adsorción del TCNQ sobre Ag(111) muesta la formación de tres diferentes fases, donde las moléculas están enlazados entre sí mediante enlaces de hidrógeno, pero con una fuerte influencia de la interacción de los grupos cyanos con el substrato de plata. Actualmente, en una de las fases la participación de los adátomos de plata no pueden ser completamente excluidos. También hay una fuerte transferencia de carga del substrato a la molécula TCNQ ( 1 e). Por el contrario, para una bicapa de moléculas TCNQ sobre Ag(111), la segunda capa está más desacoplada del substrato, y el autoensamblado está dirigido exclusivamente por la formación de enlances de hidrógeno entre las moléculas, un comportamiento similar ha sido reportado en substratos de grafeno y Au(111). Después de depositar a temperatura ambiente, se ha estudiado la adsorción del donor de electrones TTF sobre Ag(111). Ni moléculas aisladas o islas pueden ser medidas debido a la alta movilidad molecular. Después de calentar la muestra a 350 K resulta en la formación de islas bien ordenadas donde las moléculas están ligeramente inclinadas con respecto a la superficie. Los cálculos DFT y las medidas XPS muestran que en el caso de transferencia de carga, aunque muy pequeña ( 0:1 e), toma lugar en dirección opuesta, la molécula se matiene positivamente cargada. En la segunda parte de la tesis, se han estudiado mezclas de moléculas donoras y acceptoras (TCNQ-TTF, TCNE-TTF) sobre el substrato de plata (111). La superficie metálica nos permite ampliar la variedad de tales redes Donor-acceptor (D-A). Nosotros mostramos que estos sistemas exhiben diversas fases estructurales, dependiendo de la estequiometría, cada una de ellas dirigiendo a diferentes niveles de transferencia de carga. En particular, ambos TCNE y TCNQ, ambos siendo fuertes aceptores de electrones, agarrán en cada caso una carga negativa cercana a 1 e. Por el contrario, la carga sobre las moléculas TTF, siendo positivas, parece incrementarse con la aparición de TCNQ. Así controlando la proporción estequiométrica en estos compuestos, nosotros podemos ajustar las propiedades estructurales y electrónicas (por ejemplo, la función de trabajo) del sistema D-A. Finalmente, en la última parte de la tesis presenta entre dos formas isoméricas (trans y cis) del aceptor de electrones DCNQI, ambos sobre las superficies de Cu(100) y Ag(111). Los experimentos y los cálculos de DFT muestran que la barrera de isomerización es más baja que en fase gas o en solución debido a la transferencia de carga del substrato. Además, se ha estudiado la red de coordinación Fe-DCNQI mezclando átomos de hierro y moléculas DCNQI sobre Ag(111). Después de calentar a 380 K, se han observado redes unidimensionales (1-D) donde un átomo de hierro está conectado a 4 DCNQI, formando cadenas que se autoensamblan por enlaces de hidrógeno. La estructura electrónica de estas redes revela que los átomos de hierro pasan de un comportamiento metálico a un estado oxidado. En resumen, dado que la transferencia de carga en interfases metal orgánicas juegan un papel importante en la eficiencia de muchos dipositivos optoelectrónicos orgánicos, nosotros hemos estudiado el efecto de transferencia de carga en sistemas modelo de donores, aceptores y donores-aceptores sobre la superficie de Ag(111), Cu(100) y Au(111)

A survey on RF and microwave doherty power amplifier for mobile handset applications

This survey addresses the cutting-edge load modulation microwave and radio frequency power amplifiers for next-generation wireless communication standards. The basic operational principle of the Doherty amplifier and its defective behavior that has been originated by transistor characteristics will be presented. Moreover, advance design architectures for enhancing the Doherty power amplifier’s performance in terms of higher efficiency and wider bandwidth characteristics, as well as the compact design techniques of Doherty amplifier that meets the requirements of legacy 5G handset applications, will be discussed.Agencia Estatal de Investigación | Ref. TEC2017-88242-C3-2-RFundação para a Ciência e a Tecnologia | Ref. UIDP/50008/201

Nonresonant searches for axion-like particles in vector boson scattering processes at the LHC

We propose a new search for Axion-Like Particles (ALPs), targeting Vector Boson Scattering (VBS) processes at the LHC. We consider nonresonant ALP-mediated VBS, where the ALP participates as an off-shell mediator. This process occurs whenever the ALP is too light to be produced resonantly, and it takes advantage of the derivative nature of ALP interactions with the electroweak Standard Model bosons. We study the production of ZZ, Zγ, W±γ, W±Z and W±W± pairs with large diboson invariant masses in association with two jets. Working in a gauge-invariant framework, upper limits on ALP couplings to electroweak bosons are obtained from a reinterpretation of Run 2 public CMS VBS analyses. The constraints inferred on ALP couplings to ZZ, Zγ and W±W± pairs are very competitive for ALP masses up to 100 GeV. They have the advantage of being independent of the ALP coupling to gluons and of the ALP decay width. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMSThe work of J.B. was supported by the Spanish MICIU through the National Program FPU (grant number FPU18/03047). The work of J.M.R. was supported by the Spanish MICIU through the National Program FPI-Severo Ochoa (grant number PRE2019-089233). J.B. and J.M.R. acknowledge partial financial support by the Spanish MINECO through the Centro de excelencia Severo Ochoa Program under grant SEV-2016-0597, by the Spanish “Agencia Estatal de Investigacíon” (AEI) and the EU “Fondo Europeo de Desarrollo Regional” (FEDER) through the project PID2019-108892RB-I00/AEI/10.13039/501100011033. J.F.T. acknowledges support from the AEI and the EU FEDER through the project PID2020- 116262RB-C4

Analysis Gender Stereotypes in perception profile of conduct in track and field

In our current world, the existance of obstacles to acknowledge women’s equal abiliAes is real. Legally there are no barriers. The Sports Act of the government of Andalusia (Law 5/2016, July 19) determines the right to equality between genders. This is what has been called the glass ceiling. Gender stereotypes about behavior profile recreate constraints that occur in everyday pracAces, power relaAons and insAtuAonal arrangements of the general social order. Thee stereotypes are rooted in sports. In this sense. The objecAve of this study was to "interprete different gender stereotypes that exist regarding men’s and women’s profile of conduct in athleAcs.

The structural and electronic properties of nanostructured Ce1–x–yZrxTbyO2 ternary oxides: Unusual concentration of Tb3+ and metal_oxygen_metal interactions

10 pages, 12 figures, 1 table.Ceria-based ternary oxides are widely used in many areas of chemistry, physics, and materials science. Synchrotron-based time-resolved x-ray diffraction, x-ray absorption near-edge spectroscopy (XANES), Raman spectroscopy, and density-functional calculations were used to study the structural and electronic properties of Ce–Zr–Tb oxide nanoparticles. The nanoparticles were synthesized following a novel microemulsion method and had sizes in the range of 4–7 nm. The Ce1–x–yZrxTbyO2 ternary systems exhibit a complex behavior that cannot be predicted as a simple extrapolation of the properties of Ce1–xZrxO2, Ce1–xTbxO2, or the individual oxides (CeO2, ZrO2, and TbO2). The doping of ceria with Zr and Tb induces a decrease in the unit cell, but there are large positive deviations with respect to the cell parameters predicted by Vegard's rule for ideal solid solutions. The presence of Zr and Tb generates strain in the ceria lattice through the creation of crystal imperfections and O vacancies. The O K-edge and Tb LIII-edge XANES spectra for the Ce1–x–yZrxTbyO2 nanoparticles point to the existence of distinctive electronic properties. In Ce1–x–yZrxTbyO2 there is an unexpected high concentration of Tb3+, which is not seen in TbO2 or Ce1–xTbxO2 and enhances the chemical reactivity of the ternary oxide. Tb_O_Zr interactions produce a stabilization of the Tb(4f,5d) states that is responsible for the high concentration of Tb3+ cations. The behavior of Ce1–x–yZrxTbyO2 illustrates how important can be metal_oxygen_metal interactions for determining the structural, electronic, and chemical properties of a ternary oxide.The research carried out at the Chemistry Department of Brookhaven National Laboratory was financed through Contract No. DE-AC02-98CH10886 with the US Department of Energy (Division of Chemical Sciences). The NSLS is supported by the Divisions of Materials and Chemical Sciences of DOE. Work at the “Instituto de Catálisis y Petroleoquímica (CSIC)” was done with financial support from CICYT (Project No. MAT2000-1467).Peer reviewe

Approaching Sentiment Analysis by Using Semi-supervised Learning of Multidimensional Classifiers

Sentiment Analysis is defined as the computational study of opinions, sentiments and emotions expressed in text. Within this broad field, most of the work has been focused on either Sentiment Polarity classification, where a text is classified as having positive or negative sentiment, or Subjectivity classification, in which a text is classified as being subjective or objective. However, in this paper, we consider instead a real-world problem in which the attitude of the author is characterised by three different (but related) target variables: Subjectivity, Sentiment Polarity, Will to Influence, unlike the two previously stated problems, where there is only a single variable to be predicted. For that reason, the (uni-dimensional) common approaches used in this area yield suboptimal solutions to this problem. In order to bridge this gap, we propose, for the first time, the use of the novel multi-dimensional classification paradigm in the Sentiment Analysis domain. This methodology is able to join the different target variables in the same classification task so as to take advantage of the potential statistical relations between them. In addition, and in order to take advantage of the huge amount of unlabelled information available nowadays in this context, we propose the extension of the multi-dimensional classification framework to the semi-supervised domain. Experimental results for this problem show that our semi-supervised multi-dimensional approach outperforms the most common Sentiment Analysis approaches, concluding that our approach is beneficial to improve the recognition rates for this problem, and in extension, could be considered to solve future Sentiment Analysis problems

Orienteering race with QR codes in Physical Education

Monográfico con el título: "Actividades Físicas en el Medio Natural (1ª parte)"Resumen basado en el de la publicaciónTítulo, resumen y palabras clave también en inglésEl deporte de orientación es muy practicado en la actualidad, incluido en el ámbito educativo. Los actuales avances tecnológicos permiten integrar la tecnología en la práctica de la orientación, creando así interesantes e innovadoras actividades. En este sentido, se pretende mostrar una experiencia didáctica de una carrera de orientación con la integración de los códigos QR (Quick Response). Se trata de una práctica en el medio natural, en la cual se integran los códigos QR como medio de evaluación de conocimientos teóricos. La carrera está compuesta de 13 controles y en cada uno de ellos hay un código QR que al leerlo muestra una pregunta tipo test. También se muestran y detallan los pasos a seguir para organizar este tipo de actividades, siendo de gran utilidad para docentes que deseen ponerla en práctica. Estas innovaciones suponen para el alumnado un extra de motivación y hacen la actividad más atractiva, consiguiendo una mayor implicación. Asimismo, se consigue que los alumnos conozcan otras posibilidades de utilización de los dispositivos móviles y su uso adecuado.ES

Charge transfer-assisted self-limited decyanation reaction of TCNQ-type electron acceptors on Cu(100)

TCNQ derivatives adsorbed on a metal surface undergo a self-limited decyanation reaction that only affects two out of the four cyano groups in the molecule. Combined Scanning Tunneling Microscopy/X-ray Photoelectron Spectroscopy experiments and Density Functional Theory calculations relate the self-limiting behavior to the transfer of electrons from the metal to the moleculeWe thank the CCC-UAM and the RES for allocation of computer time. Our work has been supported by the MINECO of Spain (MAT2009-13488, FIS2010-18847, FIS2010-15127, FIS2012-33011, CTQ2010-17006, CTQ2011-24652/BTQ), Comunidad de Madrid (Nanobiomagnet S2009/MAT-1726, Madrisolar-2 S2009/PPQ-1533), CONSOLIDER-INGENIO on Molecular Nanoscience (CSD2007- 00010) and European Union (SMALL PITN-GA-2009-23884

Hajdu-Cheney Syndrome: A Systematic Review of the Literature.

Hajdu-Cheney syndrome (HCS) is a rare genetic disease that causes acroosteolysis and generalized osteoporosis, accompanied by a series of developmental skeletal disorders and multiple clinical and radiological manifestations. It has an autosomal dominant inheritance, although there are several sporadic non-hereditary cases. The gene that has been associated with Hajdu-Cheney syndrome is NOTCH2. The described phenotype and clinical signs and symptoms are many, varied, and evolve over time. As few as 50 cases of this disease, for which there is currently no curative treatment, have been reported to date. The main objective of this systematic review was to evaluate the results obtained in research regarding Hajdu-Cheney Syndrome. The findings are reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and were registered on the web PROSPERO under the registration number CRD42020164377. A bibliographic search was carried out using the online databases Orphanet, PubMed, and Scielo; articles from other open access sources were also considered. Finally, 76 articles were included, and after their analysis, we have obtained a series of hypotheses as results that will support further studies on this matter