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A tailored design of asymmetric hole-transporting materials (HTMs) is reported with the synthesis of a family of new HTMs based on the use of the 5H-dithieno[3,2-b:20 ,30 -d]pyran (DTP) moiety endowed with donor p-methoxytriphenylamines. A complete experimental and theoretical characterization of the optoelectronic, electrochemical and thermal properties is presented, showing more marked differences in the latter prompted by the different length of the alkyl chains (ethyl, butyl or hexyl) attached to the DTP core. This chemical design plays an important role in the morphological behavior of the new HTMs, displaying a different ability for the deposition on the top surface of the perovskite layer in perovskite solar cells (PSCs), as evidenced by scanning electron microscopy. The photovoltaic performance of the new DTP-based HTMs is highly affected by this morphological behavior, resulting in a maximum power conversion efficiency (PCE) of 17.39% for the ethyl derivative (DTPA-Et) in planar devices in combination with the state-of-the-art triple cation perovskite [(FAPbI3)0.87(MAPbBr3)0.13]0.92[CsPbI3]0.08. Otherwise, the hexyl derivative (DTPA-Hex) showed a decreased value of PCE of 15.04% due to its higher dispersity in chlorobenzene, resulting in a less uniform and lower quality film. In comparison, the reference cell using spiro-OMeTAD reaches a maximum PCE of 18.06%. This work demonstrates that DTP is a good candidate for the preparation of HTMs with high hole mobilities for exploitation in efficient and stable PSCs., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub, Descuento UCM

AbstractThe design of a well‐ordered arrangement of atoms on a solid surface has long been sought due to the envisioned applications in many different fields. On‐surface synthesis of metal‐organic networks is one of the most promising fabrication techniques. Hierarchical growth, which involves coordinative schemes with weaker interactions, favours the formation of extended areas with the desired complex structure. However, the control of such hierarchical growth is in its infancy, particularly for lanthanide‐based architectures. Here the hierarchical growth of a Dy‐based supramolecular nanoarchitecture on Au(111) is described. Such an assembly is based on a first hierarchical level of metallo‐supramolecular motifs, which in a second level of hierarchy self‐assemble through directional hydrogen bonds, giving rise to a periodic two‐dimensional supramolecular porous network. Notably, the size of the metal‐organic based tecton of the first level of hierarchy can be tailored by modifying the metal‐ligand stoichiometric ratio., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Polycyclic aromatic hydrocarbons (PAHs) are a family of organic compounds comprising two or more fused aromatic rings which feature manifold applications in modern technology. Among these species, those presenting an open-shell magnetic ground state are of particular interest for organic electronic, spintronic, and non-linear optics and energy storage devices. Within PAHs, special attention has been devoted in recent years to the synthesis and study of the acene and fused acene (periacene) families, steered by their decreasing HOMO–LUMO gap with length and predicted open-shell character above some size. However, an experimental fingerprint of such magnetic ground state has remained elusive. Here, we report on the in-depth electronic characterization of isolated peripentacene molecules on a Au(111) surface. Scanning tunnelling spectroscopy, complemented by computational investigations, reveals an antiferromagnetic singlet ground state, characterized by singlet–triplet inelastic excitations with an experimental effective exchange coupling (Jeff) of 40.5 meV. Our results deepen the fundamental understanding of organic compounds with magnetic ground states, featuring perspectives in carbon-based spintronic devices., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Tuning the electronics of nanotubes: Electron-accepting 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ) nanotweezers endowed with a carboxylic acid-containing dendrimeric moiety form exceptionally stable n-/p-type dispersions with single-walled carbon nanotubes (SWCNTs) in water. Upon photoexcitation, the nanohybrids undergo a less common electron transfer from the SWCNTs to the TCAQ nanotweezers., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

This Minireview sheds light onto the electronic communication between, on one hand, low dimensional nanocarbons – single and multiwalled 1D carbon nanotubes and 2D graphene – and, on the other hand, a variety of electroactive species en-route to novel electron donor–acceptor conjugates and hybrids in relation to their covalent and non-covalent chemistry, respectively. A common denominator to any of the highlighted conjugates/hybrids is charge transport across different scales, that is, from individual molecular conjugates/hybrids to morphologically controlled devices., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

The diacetylene skeletons of DNBD precursors are attacked on Cu(111) by copper adatoms resulting in the synthesis of organocopper metallacycles., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

SWCNTs, MWCNTs, and SWCNHs have been employed as virus-mimicking nanocarbon platforms for the multivalent presentation of carbohydrates in an artificial Ebola virus infection model assay. These carbon nanoforms have been chemically modified by the covalent attachment of glycodendrons and glycofullerenes using the CuAAC “click chemistry” approach. This modification dramatically increases the water solubility of these structurally different nanocarbons. Their efficiency in blocking DC-SIGN-mediated viral infection by an artificial Ebola virus has been tested in a cellular experimental assay, finding that glycoconjugates based on MWCNTs functionalized with glycofullerenes are potent inhibitors of viral infection., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Fully substituted peptide/[60]fullerene hexakis‐adducts offer an excellent opportunity for multivalent protein recognition. In contrast to monofunctionalized fullerene hybrids, peptide/[60]fullerene hexakis‐adducts display multiple copies of a peptide in close spatial proximity and in the three dimensions of space. High affinity peptide binders for almost any target can be currently identified by in vitro evolution techniques, often providing synthetically simpler alternatives to natural ligands. However, despite the potential of peptide/[60]fullerene hexakis‐adducts, these promising conjugates have not been reported to date. Here we present a synthetic strategy for the construction of 3D multivalent hybrids that are able to bind with high affinity the E‐selectin. The here synthesized fully substituted peptide/[60]fullerene hybrids and their multivalent recognition of natural receptors constitute a proof of principle for their future application as functional biocompatible materials., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

After the last epidemic of the Zika virus (ZIKV) in Brazil that peaked in 2016, growing evidence has been demonstrated of the link between this teratogenic flavivirus and microcephaly cases. However, no vaccine or antiviral drug has been approved yet. ZIKV and Dengue viruses (DENV) entry to the host cell takes place through several receptors, including dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), so that the blockade of this receptor through multivalent glycoconjugates supposes a promising biological target to inhibit the infection process. In order to get enhanced multivalency in biocompatible systems, tridecafullerenes appended with up to 360 1,2-mannobiosides have been synthesized using a strain-promoted cycloaddition of azides to alkynes (SPAAC) strategy. These systems have been tested against ZIKV and DENV infection, showing an outstanding activity in the picomolar range., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

AbstractThe design of dynamic structures with high recognition host‐guest materials capable to host selectively small volatile molecules is an emergent field of research with both fundamental and applied implications. The challenge of exploring novel materials with advanced functionalities has led to the development of dynamic crystalline structures promoted by soft interactions. Here, a new pure organic dynamic framework based on hexakis[60]fullerene that are held together by weak van der Waals interactions is described. This crystalline structure is capable of absorbing and releasing chloroform, through internal structural reorganization. This research provides new insight into the design of organic molecular crystals for selective adsorption applications., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Non-viral nucleic acid vectors able to display high transfection efficiencies with low toxicity and overcoming the multiple biological barriers are needed to further develop the clinical applications of gene therapy. The synthesis of hexakis-adducts of [60]fullerene endowed with 12, 24 and 36 positive ammonium groups and a tridecafullerene appended with 120 positive charges has been performed. The delivery of a plasmid containing the green fluorescent protein (EGFP) gene into HEK293 (Human Embryonic Kidney) cells resulting in effective gene expression has demonstrated the efficacy of these compounds to form polyplexes with DNA. Particularly, giant tridecafullerene macromolecules have shown higher efficiency in the complexation and transfection of DNA. Thus, they can be considered as promising non-viral vectors for transfection purposes., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

A family of hexakis-substituted [60]fullerene adducts endowed with the well-known tridentate 2,6- bis(pyrazol-1-yl)pyridine (bpp) ligand for spin-crossover (SCO) systems has been designed and synthesized. It has been experimentally and theoretically demonstrated that these molecular scaffolds are able to form polynuclear SCO complexes in solution. UV-vis and fluorescence spectroscopy studies have allowed monitoring of the formation of up to six Fe(II)–bpp SCO complexes. In addition, DFT calculations have been performed to model the different complexation environments and simulate their electronic properties. The complexes retain SCO properties in the solid state exhibiting both thermaland photoinduced spin transitions, as confirmed by temperature-dependent magnetic susceptibility and Raman spectroscopy measurements. The synthesis of these complexes demonstrates that [60]fullerene hexakis-adducts are excellent and versatile platforms to develop polynuclear SCO systems in which a fullerene core is surrounded by a SCO molecular shell., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Weak forces can play an essential role in chemical reactions. Controlling such subtle forces in reorganization processes by applying thermal or chemical stimuli represents a novel synthetic strategy and one of the main targets in supramolecular chemistry. Actually, to separate the different supramolecular contributions to the stability of the 3D assemblies is still a major challenge. Therefore, a clear differentiation of these contributions would help in understanding the intrinsic nature as well as the chemical reactivity of supramolecular ensembles. In the present work, a controlled reorganization of an hexakis[60]fullerene-based molecular compound purely governed by the weakest van der Waals interactions known, i.e. the dihydrogen interaction – usually called sticky fingers – is illustrated. This pre-reorganization of the hexakis[60]fullerene under mild conditions allows a further selective hydrogenation of the crystalline material via hydrazine vapors exposure. This unique two-step transformation process is monitored by single-crystal to single-crystal diffraction (SCSC) which allows the direct observation of the molecular movements in the lattice and the subsequent solid–gas hydrogenation reaction., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

A novel Fe(iic>) MOF is reported to show an unprecedented 1D chain with a perfect linearity. Moreover, this structure expands to a third dimension to form a very robust MOF. The structure displays an amazing resemblance to a 14th century mosaic found in the Alhambra Palace in Granada., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

The synthesis and characterization of three novel HTMs with different highest occupied molecular orbital (HOMO) energy levels and their performances in MAPbI3-based devices in comparison with Spiro-OMeTAD is reported. Without systematic optimization, the HTMs performed well. The devices delivered fill factors comparable to the one with Spiro-OMeTAD but suffered from short-circuit current. Interestingly, despite the significant differences in HOMO energy levels, all three HTMs generated the same open-circuit voltage (VOC). We explored the performance limiting factors of the HTMs by simple transient photovoltage/photocurrent (TPV/TPC) measurements along with Drift-diffusion simulations. We found no correlation between HOMO energy levels of the HTMs and VOC of the devices. Performances of the devices are limited by high trap density as well as low carrier mobility of the HTMs, and by the shunts present in the devices. Furthermore, the high trap density and low carrier mobility of the HTM are found to induce ion migration effect in the device causing slow decaying components in TPV/TPC . Nevertheless, it is confirmed that JSC and VOC, measured at steady state, are not influenced by the ion migration effect. These HTMs can be improved further by optimizing their conductivity, trap density, morphology, and can be used as alternatives to Spiro-OMeTAD or other expensive, synthetically challenging HTMs. The simple and inexpensive approach presented in this work can also be applied for effectively evaluating charge transporting materials for perovskite solar cells, European Research Council, MINECO, Comunidad de Madrid, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Among the plethora of polycyclic structures that have emerged in recent years, indenofluorenes comprise a unique class of compounds due to their potential in organic electronic systems such as OLEDs, OFETs, and OPVCs. However, the synthesis of fully conjugated indenofluorenes without bulky groups on the apical carbons under standard chemistry conditions is not easily accessible. In this regard, on-surface synthesis has appeared as a newly developing field of research, which exploits the use of well-defined solid surfaces as confinement templates to initiate and develop chemical reactions. Here, we demonstrate the successful fabrication of indeno[1,2-b]fluorene p-conjugated polymers linked via cumulene-like connections on well-defined metallic surfaces under ultra-high vacuum conditions. The structure and electronic properties of the formed polymers have been precisely characterized by scanning tunneling microscopy, noncontact atomic force microscopy and scanning tunneling spectroscopy, complemented by computational investigations, Comunidad de Madrid, Ministerio de Ciencia e Innovación, MINECO, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

A complementary double‐covalent functionalization of single‐wall carbon nanotubes (SWCNTs) that involves both solubilizing ionic liquids and electroactive moieties is reported. Our strategy is a simple and efficient methodology based on the stepwise functionalization of the nanotube surface with two different organic moieties. In a first instance, oxidized SWCNTs are amidated with ionic liquid precursors, and further treated with butyl bromide to afford SWCNTs functionalized with 1‐butylimidazolium bromide. This approach allows tuneable polarity induced by anion exchange, which has an effect on the relative solubility of the modified SWCNTs in water. Subsequently, a 1,3‐dipolar cycloaddition reaction was performed to introduce the electron‐acceptor 11,11,12,12‐tetracyano‐9,10‐anthra‐quinodimethane (TCAQ) unit on the SWCNTs. Furthermore, to evaluate the influence of the functional group position, the TCAQ electroactive molecule was anchored through an esterification reaction onto previously oxidized SWCNTs, followed by the Tour reaction to introduce the ionic liquid functions. IR and Raman spectroscopies, thermogravimetric analysis (TGA), UV/Vis/NIR spectroscopy, transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS) were employed and clearly confirmed the double‐covalent functionalization of the SWCNTs., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

The thermoelectric properties of molecular junctions consisting of a metal Pt electrode contacting [60]fullerene derivatives covalently bound to a graphene electrode have been studied by using a conducting-probe atomic force microscope (c-AFM). The [60]fullerene derivatives are covalently linked to the graphene via two meta-connected phenyl rings, two para-connected phenyl rings, or a single phenyl ring.We find that the magnitude of the Seebeck coefficient is up to nine times larger than that of Au−C60−Pt molecular junctions.Moreover,the sign of the thermopower can be either positiveor negative depending on the details of the binding geometry and on the local value of the Fermi energy. Our results demonstrate the potential of using graphene electrodes for controlling and enhancing the thermoelectric properties of molecular junctions and confirm the outstanding performance of [60]fullerene derivatives., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

AbstractWe report on the synthesis and characterization of atomically precise one‐dimensional diradical peripentacene polymers on a Au(111) surface. By means of high‐resolution scanning probe microscopy complemented by theoretical simulations, we provide evidence of their magnetic properties, which arise from the presence of two unpaired spins at their termini. Additionally, we probe a transition of their magnetic properties related to the length of the polymer. Peripentacene dimers exhibit an antiferromagnetic (S=0) singlet ground state. They are characterized by singlet–triplet spin‐flip inelastic excitations with an effective exchange coupling (Jeff) of 2.5 meV, whereas trimers and longer peripentacene polymers reveal a paramagnetic nature and feature Kondo fingerprints at each terminus due to the unpaired spin. Our work provides access to the precise fabrication of polymers featuring diradical character which are potentially useful in carbon‐based optoelectronics and spintronics., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Graphene is a unique material with outstanding mechanical and electronic properties. For solution processes graphene layers have to be stabilized by means of molecular or supramolecular chemical derivatization, prior to their transfer to solid substrates. The most common chemical methodology for the preparation of graphene involves the formation of graphene oxide under highly oxidizing conditions, which even after reduction, lacks the electronic quality of pristine graphene. Presently, there is increasing concern in the chemical community about the starting material quality, and recent efforts are directed to wet chemical approaches toward high-quality graphene flakes which encompass the use of graphite as initial material. In addition, epitaxial growth of graphene on metallic surfaces is becoming a powerful technique for the production of pristine graphene with a control on its electronic properties, somehow due to the supramolecular interaction with the metallic surface. Current approaches for the preparation of modified pristine graphene are the aim of this review., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

2023 Acuerdo transformativo financiado por la CRUE, The covalent incorporation of C60 and C70 derivatives of the well-known n-type organic semiconductor PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) onto carbon dots (CD) is described. Morphological and structural characterization reveal combined features of both pristine starting materials (CD and PCBM). Electrochemical investigations evidenced the existence of additional reduction processes to that of CD or PCBM precursors, showing rich electron-acceptor capabilities, with multistep processes in an affordable and narrow electrochemical window (ca. 1.5 V). Electronic communication in the obtained nanoconjugated species were derived from steady-state absorption and emission spectroscopies, which showed bathochromically shifted absorptions and emissions well entering the red region. Finally, the lower fluorescence quantum yield of CD-PCBM nanoconjugates, compared with CD, and the fast decay of the observed emission of CD, support the existence of an electronic communication between both CD and PCBM units in the excited state., Ministerio de Ciencia e Innovación (España), Comunidad de Madrid, European Commission, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub, APC financiada por la UCM

CRUE-CSIC (Acuerdos Transformativos 2022), Scholl oxidation has become an essential reaction in the bottom-up synthesis of molecular nanographenes. Herein, we describe a Scholl reaction controlled by the electronic effects on the starting substrate (1 a, b). Anthracene-based polyphenylenes lead to spironanographenes under Scholl conditions. In contrast, an electron-deficient anthracene substrate affords a helically arranged molecular nanographene formed by two orthogonal dibenzo[fg,ij]phenanthro-[9,10,1,2,3-pqrst]pentaphene (DBPP) moieties linked through an octafluoroanthracene core. Density Functional Theory (DFT) calculations predict that electronic effects control either the first formation of spirocycles and subsequent Scholl reaction to form spironanographene 2, or the expected dehydrogenation reaction leading solely to the helical nanographene 3. The crystal structures of four of the new spiro compounds (syn 2, syn 9, anti 9 and syn 10) were solved by single crystal X-ray diffraction. The photophysical properties of the new molecular nanographene 3 reveal a remarkable dual fluorescent emission., Ministerio de Ciencia, Innovación y Universidades (España), Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Fullerene derivatives have been used as electron acceptor and transport materials in organic photovoltaics as well as in perovskite solar cells. Among them, [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) has been one of the most widely used, in combination with poly-3-hexylthiophene (P3HT) as an electron donor semiconducting polymer, for the fabrication of organic bulk heterojunction solar cells (BHJ-OSC). In this work, a steroid-fullerene hybrid was synthesized through the Bingel–Hirsch reaction to compare its properties with PC61BM as the reference structure. Different spectroscopic techniques were employed to characterize the new fullerene derivative, namely 1D and 2D nuclear magnetic resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), and high-resolution mass spectrometry (HRMS). In addition, thermogravimetric analysis (TGA), and cyclic voltammetry were also performed. The characterization was completed by transmission electron microscopy (TEM), which explore the hybrid‘s morphology, where the presence of the steroid moiety increases the solubility of the fullerene material. DFT/PBE−D3(BJ)/6-311G(d,p) calculations for both the steroid-fullerene hybrid and PC61BM allowed to obtain geometry optimizations and electronic structure data. A comparative study to analyze the nature of the electronic properties of the synthesized steroid-[60]fullerene hybrid and PC61BM with an oligomer of ten thiophene units, used in the active layer of organic solar cells, was carried out. Electron density maps using the [CIS|CNDOL/21] approach illustrate the photoexcitation of the donor followed by an electron-charge transfer to the acceptor fullerene., Ministerio de Ciencia e Innovación (España), Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub, Descuento UCM

Since WHO has declared the COVID-19 outbreak a global pandemic, nearly seven million deaths have been reported. This efficient spread of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is facilitated by the ability of the spike glycoprotein to bind multiple cell membrane receptors. Although ACE2 is identified as the main receptor for SARS-CoV-2, other receptors could play a role in viral entry. Among others, C-type lectins such as DC-SIGN are identified as efficient trans-receptor for SARS-CoV-2 infection, so the use of glycomimetics to inhibit the infection through the DC-SIGN blockade is an encouraging approach. In this regard, multivalent nanostructures based on glycosylated [60]fullerenes linked to a central porphyrin scaffold have been designed and tested against DC-SIGN-mediated SARS-CoV-2 infection. First results show an outstanding inhibition of the trans-infection up to 90%. In addition, a deeper understanding of nanostructure-receptor binding is achieved through microscopy techniques, high-resolution NMR experiments, Quartz Crystal Microbalance experiments, and molecular dynamic simulations., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

The main part of this thesis focuses on the production and characterisation of carbon nanodots. Regarding the production methods of the CNDs chosen in this work, CNDs produced by two clearly different bottom-up methods have been studied in detail. On the one hand, the solvothermal method has been used. This method consists of heating a liquid, in a closed container, above its boiling point, generating a pressure higher than atmospheric pressure, and thus inducing the condensation of CNDs. The obvious advantages of this synthetic method are: it is easy, cheap and environmentally friendly (provided that the solvent used in the solvothermal method is an environmentally friendly solvent, in our case we used water and ethanol). All these advantages provided a great opportunity to easily prepare and investigate CNDs, which, when prepared by this method, were found to have promising properties such as solubility in aqueous media, biocompatibility, photocatalytic activity in heterostructures with TiO2 and biocidal properties that can be employed to prepare biocidal polymer surfaces. The combination of the advantages proposed by the synthetic method and the promising properties of the products obtained have made this method the most common synthetic procedure for the production of CNDs..., La parte principal de esta tesis se centra en la producción y caracterización de los nanopuntos de carbono. En cuanto a los métodos de producción de los CNDs elegidos en este trabajo, se han estudiado en detalle los CNDs producidos por dos métodos ascendentes claramente diferentes. Por un lado, se ha utilizado el método solvotérmico. Este método consiste en calentar un líquido, en un recipiente cerrado, por encima de su punto de ebullición, generando una presión superior a la atmosférica, e induciendo así la condensación delos CNDs. Las ventajas evidentes de este método sintético son: es fácil, barato y respetuoso con el medio ambiente (siempre que el disolvente utilizado en el método solvotérmico sea un disolvente respetuoso con el medio ambiente, en nuestro caso hemos utilizado agua y etanol). Todas estas ventajas proporcionaron una gran oportunidad para preparar e investigar fácilmente los CNDs, los cuales, al ser preparados por este método, resultaron tener propiedades prometedoras como la solubilidad en medios acuosos, la biocompatibilidad, la actividad fotocatalítica en heteroestructuras con TiO2 y propiedades biocidas que pueden ser empleadas para preparar superficies poliméricas biocidas. La combinación de las ventajas propuestas por el método sintético y las prometedoras propiedades de los productos obtenidos han hecho de este método el procedimiento sintético más común para la producción de CNDs...

En los últimos años se ha desarrollado una nueva metodología de síntesis denominada síntesis en o sobre superficie. Este es un campo de investigación extremadamente prometedor destinado a crear nuevos materiales orgánicos que no pueden sintetizarse por métodos convencionales, utilizando superficies sólidas bien definidas como plataformas para iniciar reacciones químicas. Una de las principales herramientas empleadas en la nanociencia son los microscopios de sonda de barrido (SPM). Esta familia de microscopios se inició con la invención del STM, donde sólo unos años después, se desarrolló también el microscopio de fuerza atómica (AFM, Atomic Force Microscope, por sus siglas en inglés) como técnica complementaria. Inspirados en la investigación preliminar del grupo con el 9,10-bis(dibro-mometilen)-9,10-dihidroantraceno, se decidió profundizar en el conoci-miento de los polímeros derivados de aceno y periaceno utilizando este novedoso protocolo. Para ello, se sintetizaron y funcionalizaron diferen-tes quinonas simétricas de acenos y periacenos empleando el protocolo de olefinación de Ramírez, para introducir las funcionalidades gem-di-bromovinileno (=CBr2)..., In recent years, a new synthetic methodology called on-surface synthesis has been developed. On-surface synthesis is an extremely promising field of research aimed at creating new organic materials that cannot be synthesized by conventional methods, using well-defined solid surfaces as templates to initiate chemical reactions. One of the main tools used in nanoscience are scanning probe microscopes (SPM). This family of mi-croscopes started with the invention of the STM, where only a few years later, the Atomic Force Microscope (AFM) was also developed as a com-plementary technique.Inspired by the group's preliminary research with 9,10-bis(dibromometh-ylene)-9,10-dihydroanthracene, it was decided to deepen the under-standing of acene- and periacene-derived polymers using this novel pro-tocol. For this purpose, different symmetric quinones of acenes and per-iacenes are synthesized and functionalized using the Ramírez olefination protocol to introduce gem-dibromovinylene (=CBr2) functionalities...

Multivalent ligand presentation is a powerful strategy for the development of specific binders and inhibitors. Peptide/[60]fullerene hybrids have now been synthesized that exploit the complete substitution of the fullerene scaffold to afford globular structures presenting twelve copies of a peptide ligand for the recognition of E-selectin. Fully substituted peptide/[60]fullerene hexakis-adducts offer an excellent opportunity for multivalent protein recognition. In contrast to monofunctionalized fullerene hybrids, peptide/[60]fullerene hexakis-adducts display multiple copies of a peptide in close spatial proximity and in the three dimensions of space. High affinity peptide binders for almost any target can be currently identified by in vitro evolution techniques, often providing synthetically simpler alternatives to natural ligands. However, despite the potential of peptide/[60]fullerene hexakis-adducts, these promising conjugates have not been reported to date. Here we present a synthetic strategy for the construction of 3D multivalent hybrids that are able to bind with high affinity the E-selectin. The here synthesized fully substituted peptide/[60]fullerene hybrids and their multivalent recognition of natural receptors constitute a proof of principle for their future application as functional biocompatible materials

CRUE-CSIC (Acuerdos Transformativos 2021), Ministerio de Ciencia e Innovación (MICINN), Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2021), 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., Ministerio de Economía y Competitividad (MINECO), Centro de Excelencia Severo Ochoa, Generalitat de Catalunya, European Social Funds and the SUR del DEC de la Generalitat de Catalunya, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Nanotechnology has emerged as an outstanding field into several sciences. After the discovery of novel carbon nanostructures, such as fullerenes, carbonnano tubes or graphene, materials science has focused its attention on those nanostructures. Due to their electrical, mechanical and optical properties, they appear to be ideal candidates for the development of materials for the future with a wide range of applicability. Among this, biological applications play an important role. The chemical modification of these nanomaterials allows to increase their biocompatibility..., La nanotecnología ha surgido como un campo de gran importancia dentro dela ciencia. Después del descubrimiento de novedosas nanoformas de carbono como los fullerenos, nanotubos de carbono o grafeno, la ciencia de materiales ha centrado su atención en estas nanoestructuras. Debido a sus excepcionales propiedades eléctricas, mecánicas y ópticas, las nanoformas de carbono son buenos candidatos para el desarrollo de futuros materiales con un gran rango de aplicabilidad. En este sentido, las aplicaciones biológicas juegan un papel importante. La modificación química de estos nanomateriales permite un aumento de su biocompatibilidad...

Perovskite solar cells (PSCs) have become one of the most promising technologies for searching clean alternatives to fossil fuels in order to achieve a sustainable society taking advantage of the unlimited solar energy. In a few years of research, PSCs have reached promising efficiencies up to 25% which are comparable to the commercial silicon-based cells. As a means to improve the efficiencies and the stability of PSCs, the research has been closely connected to the design of highly efficient charge selective layers such as electron (ETMs) and hole-transporting materials (HTMs). Although the charge selective layer could present either inorganic or polymeric structures, organic-based small molecules have been demonstrated as the most promising alternative for the preparation of highly efficient PSCs..., Las células solares de perovskita (PSCs) se han convertido en una de las tecnologías más prometedoras en la búsqueda de alternativas limpias a los combustibles fósiles para alcanzar una sociedad sostenible aprovechando la energía solar ilimitada. En pocos años de investigación, PSCs han alcanzado eficiencias prometedoras por encima del 25% que son comparables a las células solares comerciales basadas en silicio. Con el fin de mejorar las eficiencias y la estabilidad de las PSCs, la investigación también ha estado relacionada con el diseño de capas selectivas de carga de alta eficiencia como los transportadores de electrones (ETMs) y de huecos (HTMs). Aunque las capas selectivas de carga pueden presentar una estructura inorgánica o polimérica, las moléculas orgánicas pequeñas han demostrado ser las alternativas más prometedoras para la preparación de PSCs de alta eficiencia..

Nanotechnology has emerged as an outstanding field into several sciences. After the discovery of novel carbon nanostructures, such as fullerenes, carbonnano tubes or graphene, materials science has focused its attention on those nanostructures. Due to their electrical, mechanical and optical properties, they appear to be ideal candidates for the development of materials for the future with a wide range of applicability. Among this, biological applications play an important role. The chemical modification of these nanomaterials allows to increase their biocompatibility...

Perovskite solar cells (PSCs) have become one of the most promising technologies for searching clean alternatives to fossil fuels in order to achieve a sustainable society taking advantage of the unlimited solar energy. In a few years of research, PSCs have reached promising efficiencies up to 25% which are comparable to the commercial silicon-based cells. As a means to improve the efficiencies and the stability of PSCs, the research has been closely connected to the design of highly efficient charge selective layers such as electron (ETMs) and hole-transporting materials (HTMs). Although the charge selective layer could present either inorganic or polymeric structures, organic-based small molecules have been demonstrated as the most promising alternative for the preparation of highly efficient PSCs...

After the discovery of fullerenes, carbon nanotubes and graphene, the classical allotropes of carbon were enriched with new structures and new potential applications. C60, with its singular spherical shape, its size (~1nm) and its remarkable electronic and photophysical properties, has emerged as a promising material for many potential applications in materials, nanotechnology and biomedical sciences. Objectives 1. Synthesis and electronic properties of fullerenes-fused unsaturated carbocyclesWe will extend the scope of asymmetric phosphine-catalysed cycloaddition of allenoates onto fullerenes through the variation of all the elements involved in the reaction. In addition, the intrinsic electronic mobility of these fullerenic derivatives will be measured with the objective of evaluating the influence of the optical purity on this property. 2. Reversible stereodivergent cycloaddition of a helicene derivative onto [60]fullerene: a chiral resolution strategyWe will try to take advantage of the stereoselective and reversible covalent fullerene chemistry as a tool for the resolution of racemates. For this purpose, enantioselective pyrrolidino[60]fullerenes will be prepared from a racemic iminoester derived from [6]helicene...

Nowadays, the degradation of the environment and the climate change are some of the main concerns of our society. Therefore, a lot of effort has been invested in the search for new alternatives to fossil fuels. One interesting solution to this problem is to use solar energy as a renewable supply. In nature, it is well-known that solar energy can be transformed into chemical energy by means of photosynthetic processes. This concept has inspired a lot of efforts in the development of new artificial photosynthetic systems composed by donoracceptor(D-A) assemblies. Specifically, in recent years, the combination of carbon nanoforms and light-harvesting dyes using covalent and supramolecular approaches has been widely studied. In this sense, the improvement in the formation methodology of new D-A assemblies, as well as the understanding of the charge transfer processes involved in these systems, are the main keys to create new artificial systems with a potential applicability...

Accomplishing the great level of complexity and sophistication of natural systems is presented as a major challenge to scientists. A multidisciplinary approach is intended to design and create the next generation of advanced materials and, in this regard, supramolecular chemistry can play a key role. In particular, the combination of organic molecules and biomolecules has appeared as a fascinating approach to take advantage of the self-assembling properties and great specificity of the biological systems to obtain materials with enhanced photophysical features. Peptides and proteins are crucial components in living beings and have demonstrated their versatility to construct artificial systems. Although great progress has been made in terms of control and diversity of structure, translating structure into functionality still remains as a major challenge...

La investigación que se ha llevado a cabo en este trabajo (Fotosensibilización de oxígeno singlete: aplicaciones al estudio de la fotooxidación de tiocetonas y fotoerradicación de H. pylori) centra su interés en el aprovechamiento de la energía transportada por la luz y su transferencia mediante fotosensibilización a la molécula de oxígeno para generar su estado excitado de menor energía, el oxígeno molecular singlete (1O2). La producción de esta especie reactiva del oxígeno puede ser aplicada en campos tan diversos como la síntesis química en el contexto de la Química Verde (Green Chemistry), en métodos de descontaminación medioambiental como los procesos avanzados de oxidación(Advanced Oxidation Processes), o en nuevos tratamientos médicos como las terapias fotodinámicas (Photodynamic Therapies) contra microorganismos resistentes a antibióticos o contra algunos tipos de cáncer. En definitiva, este estudio persigue avanzar en el conocimiento sobre la aplicación alternativa de la luz, un recurso potencialmente inagotable, para conseguir algunos de los objetivos fundamentales que se plantea la sociedad para un futuro cercano: el desarrollo de una industria química sostenible, la conservación del medioambiente, así como nuevos caminos para mejorar la salud y vivir mejor...

Nowadays, the degradation of the environment and the climate change are some of the main concerns of our society. Therefore, a lot of effort has been invested in the search for new alternatives to fossil fuels. One interesting solution to this problem is to use solar energy as a renewable supply. In nature, it is well-known that solar energy can be transformed into chemical energy by means of photosynthetic processes. This concept has inspired a lot of efforts in the development of new artificial photosynthetic systems composed by donoracceptor(D-A) assemblies. Specifically, in recent years, the combination of carbon nanoforms and light-harvesting dyes using covalent and supramolecular approaches has been widely studied. In this sense, the improvement in the formation methodology of new D-A assemblies, as well as the understanding of the charge transfer processes involved in these systems, are the main keys to create new artificial systems with a potential applicability..., Actualmente, unas de las mayores preocupaciones de nuestra sociedad son la degradación del medio ambiente y el cambio climático. Debido a esto, se ha invertido mucho esfuerzo en la búsqueda de nuevas alternativas a los combustibles fósiles. Una solución interesante a este problema es el uso de la energía solar como fuente de energía renovable. Como bien sabemos, los procesos fotosintéticos observados en la naturaleza son capaces de transformarla energía solar en energía química. Buscando inspiración en este concepto, se ha puesto mucho esfuerzo en el desarrollo de nuevos sistemas foto sintéticos artificiales basados en complejos de tipo dador-aceptor (D-A). Concretamente, en los últimos años, ha sido muy estudiada la formación de sistemas basados en nanoformas de carbono y colorantes con gran capacidad de absorción de luz, a través de estrategias covalentes y supramoleculares. En este sentido, las claves para la creación de sistemas artificiales con una potencial aplicabilidad son la mejora de las metodologías para la formación de los sistemas D-A, así como la comprensión de los procesos de trasferencia de carga que operan en este tipo de sistemas...

La investigación que se ha llevado a cabo en este trabajo (Fotosensibilización de oxígeno singlete: aplicaciones al estudio de la fotooxidación de tiocetonas y fotoerradicación de H. pylori) centra su interés en el aprovechamiento de la energía transportada por la luz y su transferencia mediante fotosensibilización a la molécula de oxígeno para generar su estado excitado de menor energía, el oxígeno molecular singlete (1O2). La producción de esta especie reactiva del oxígeno puede ser aplicada en campos tan diversos como la síntesis química en el contexto de la Química Verde (Green Chemistry), en métodos de descontaminación medioambiental como los procesos avanzados de oxidación(Advanced Oxidation Processes), o en nuevos tratamientos médicos como las terapias fotodinámicas (Photodynamic Therapies) contra microorganismos resistentes a antibióticos o contra algunos tipos de cáncer. En definitiva, este estudio persigue avanzar en el conocimiento sobre la aplicación alternativa de la luz, un recurso potencialmente inagotable, para conseguir algunos de los objetivos fundamentales que se plantea la sociedad para un futuro cercano: el desarrollo de una industria química sostenible, la conservación del medioambiente, así como nuevos caminos para mejorar la salud y vivir mejor..., The research presented in this work (Photosensitization of singlet oxygen: applications to the study of photooxidation of thioketones and photoeradication of H. pylori) is focused on the current interest on taking advantage of the energy transported by light and its transfer by photosensitization to the oxygen molecule to generate its excited state of lowest energy, singlet molecular oxygen (1O2). The production of this reactive oxygen species can be applied in fields as diverse as chemical synthesis in the context of Green Chemistry, in environmental decontamination methods such as Advanced Oxidation Processes, or in new medical treatments such as Photodynamic Therapies against antibiotic-resistant microorganisms or against some types of cancer. In short, this study aims to advance knowledge about the alternative application of light, a potentially inexhaustible resource, in order to achieve some of the fundamental objectives that society sets for the near future: the development of a sustainable chemical industry, the conservation of the environment, as well as new ways to improve health and live better...

The field of molecular electronics, based on the use of single molecules or nanoscale collections of single molecules as electronic components, has represented, and still now represents, a seductive playground for scientists where there is still much to do. Over the past decade, experiments and theory have allowed to greatly enhance the comprehension of the working principles at the base of molecular junctions. Thus, the interest has shifted over other less known, investigated or understood, aspects involving structural or theoretical challenges. So far, most of research efforts in this field were mainly devoted to the investigation of the electrical conductance of covalently conjugated molecular wires. Now, instead, more complex structures (i.e. based on supramolecular systems), less known features (namely, the thermoelectric properties of these systems) and hybrid materials begin to grab the scientific attention of the area..., El campo de la electrónica molecular, basado en el uso de moléculas individuales o un conjunto de ellas como componentes de dispositivos electrónicos, ha representado, y todavía representa, un área de trabajo seductora para los científicos en la que todavía hay mucho por hacer. Durante la última década, el desarrollo de procedimientos experimentales junto con la parte teórica han permitido mejorar en gran medida la comprensión de los principios básicos de las uniones moleculares. Por lo tanto, el interés se ha dirigido hacia otros aspectos menos conocidos, investigados o entendidos, que implican desafíos estructurales o teóricos. Hasta ahora en este campo, la mayoría de los esfuerzos en investigación se han dedicado al estudio de la conductancia eléctrica de cables moleculares conjugados covalentemente. Ahora, en cambio, estructuras más complejas (por ejemplo, basadas en sistemas supramoleculares), características menos conocidas (como las propiedades termoeléctricas de estos sistemas) y nuevos materiales híbridos comienzan a captar la atención científica del área...

Accomplishing the great level of complexity and sophistication of natural systems is presented as a major challenge to scientists. A multidisciplinary approach is intended to design and create the next generation of advanced materials and, in this regard, supramolecular chemistry can play a key role. In particular, the combination of organic molecules and biomolecules has appeared as a fascinating approach to take advantage of the self-assembling properties and great specificity of the biological systems to obtain materials with enhanced photophysical features. Peptides and proteins are crucial components in living beings and have demonstrated their versatility to construct artificial systems. Although great progress has been made in terms of control and diversity of structure, translating structure into functionality still remains as a major challenge..., Conseguir el gran nivel de complejidad y sofisticación que presentan los sistemas naturales constituye un gran reto científico. Para el diseño y desarrollo de una nueva generación de materiales avanzados es necesario un enfoque multidisciplinar, donde la química supramolecular puede jugar un papel clave. En concreto, la combinación de moléculas orgánicas y biomoléculas se figura como una estrategia fascinante con la que beneficiarse de la capacidad de auto-ensamblaje y la gran especificidad de los sistemas biológicos y, así, obtener materiales con mejores propiedades fotofísicas. Los péptidos y las proteínas son componentes esenciales en los seres vivos y han demostrado su gran versatilidad a la hora de crear sistemas artificiales. Sin embargo, pese al gran progreso conseguido en términos de control y diversidad estructural, su aplicación práctica continúa presentándose como un gran reto...

After the discovery of fullerenes, carbon nanotubes and graphene, the classical allotropes of carbon were enriched with new structures and new potential applications. C60, with its singular spherical shape, its size (~1nm) and its remarkable electronic and photophysical properties, has emerged as a promising material for many potential applications in materials, nanotechnology and biomedical sciences. Objectives 1. Synthesis and electronic properties of fullerenes-fused unsaturated carbocyclesWe will extend the scope of asymmetric phosphine-catalysed cycloaddition of allenoates onto fullerenes through the variation of all the elements involved in the reaction. In addition, the intrinsic electronic mobility of these fullerenic derivatives will be measured with the objective of evaluating the influence of the optical purity on this property. 2. Reversible stereodivergent cycloaddition of a helicene derivative onto [60]fullerene: a chiral resolution strategyWe will try to take advantage of the stereoselective and reversible covalent fullerene chemistry as a tool for the resolution of racemates. For this purpose, enantioselective pyrrolidino[60]fullerenes will be prepared from a racemic iminoester derived from [6]helicene..., Con el descubrimiento de los fullerenos por H. W. Kroto, R. F. Curl y R. E. Smalley en 1985, se enriqueció la variedad de alótropos del carbono. El C60, con su singular forma esférica, su tamaño (~1nm) y sus destacables propiedades electrónicas y fotofísicas, surgió como un material prometedor para muchas aplicaciones, tanto en materiales y nanotecnología como en ciencias biomédicas. Objetivos 1. Síntesis y propiedades electrónicas de derivados carbocíclicos insaturados fusionados a fullerenos Extenderemos la metodología de la reacción de cicloadición asimétrica de alenoatos sobre fullerenos catalizada por fosfinas mediante la variación de todos los elementos que intervienen en la reacción. Además, se llevará a cabo la medida de la movilidad electrónica intrínseca de estos derivados fullerénicos y se evaluará cómo afecta la pureza óptica a dicha propiedad. 2. Cicloadición estereodivergente reversible de un derivado de heliceno sobre el [60]fullereno: una estrategia de resolución quiral Realizaremos el estudio de la reversibilidad en la química covalente del fullereno como herramienta para la resolución de racematos. Para ello, se prepararán fulleropirrolidinas enantioselectivas a partir de un iminoéster racémico derivado de [6]heliceno...

El carbono es uno de los 92 elementos qu.micos naturales de nuestro planeta y constituye aproximadamente el 0,1 % de la corteza terrestre. Despu.s del oxígeno, es el elemento químico más abundante en masa (18 %) en el cuerpo humano.

The field of molecular electronics, based on the use of single molecules or nanoscale collections of single molecules as electronic components, has represented, and still now represents, a seductive playground for scientists where there is still much to do. Over the past decade, experiments and theory have allowed to greatly enhance the comprehension of the working principles at the base of molecular junctions. Thus, the interest has shifted over other less known, investigated or understood, aspects involving structural or theoretical challenges. So far, most of research efforts in this field were mainly devoted to the investigation of the electrical conductance of covalently conjugated molecular wires. Now, instead, more complex structures (i.e. based on supramolecular systems), less known features (namely, the thermoelectric properties of these systems) and hybrid materials begin to grab the scientific attention of the area...

Uno de los objetivos de la ciencia es la búsqueda de fuentes de energía alternativas para solucionar la demanda cada vez más creciente de energía. Una fuente de enrgía inagotable a tener en cuenta es el sol. De ahí que el diseño de sistemas fotosintétivos artificiales capaces de absorber la energía solar para su conversión en energía eléctrica, sea una de las aproximaciones más desarrolladas en las últimas décadas.Objetivos. Capítulo 1: estudiar los procesos de transferencia electrónica fotoinducida en una nueva serie de díadas y tríadas supramoleculares, basadas en fullereno y SWCNTs, como unidades aceptoras de electrones, y porfirina y tetratiafulvaleno pi extendido como unidades dadoras de electrones.Capítulo 2: Síntesis de nuevos agregados helicoidales basadoso en moléculas discóticas con simetría c3 funcionalizados con unidades de porfirinas, para su aplicación en dispositivos optoelectrónicos.Resultados y discusiónCapítulo 1Tríadas supramoleculares dsa basadas en oligo p fenileno de diferente longitud como espaciador.En la primera parte de la presente memoria, se diseñó y sintetizó como unidad aceptora de electrones, una serie de derivados de fullereno covalentemente unido a un espaciador de tipo oligo p fenileno de diferente longitud con un grupo ácido en posición terminal. También se llevó a cabo la síntesis de la unidad complementaria dadora de electrones basada en porfirina o tetratiafulvaleno pi extendido funcionalizada con un grupo amidina. El estudio de la formación del complejo supramolecular dsa se desarrollo a través de diferentes técnicas espectroscópicas tales como UV vis y fluorescencia. Estos estudios revelaron la formación del complejo supramolecular con constantes de asociación en el orden de 10 10 m. Estos valores tan altos de la constante de asociación están asociados al fuerte carácter electrostático del enlace carboxilato-amidina. Además, los estudios fotofísicos mostraron que existía un proceso de transferencia electrónica fotoinducida ent

Los fullerenos, descubiertos por H. W. Kroto, R. F. Curl y R. E. Smalley en 1985, han recibido una gran atención por parte de la comunidad científica debido a sus notables propiedades electrónicas y fotofísicas, convirtiéndose en una de las moléculas más intensamente investigadas. Teniendo en cuenta sus propiedades únicas derivadas de una constitución química bien definida, los fullerenos se consideran un material prometedor para diversas aplicaciones. Objetivos Síntesis de Híbridos Quirales Metal-Fullereno Diseño y síntesis de nuevos híbridos quirales de fullereno dotados con diferentes metales, con un completo control sobre los nuevos centros estereogénicos creados, con la quiralidad centrada en el metal. Actividad Catalítica de Híbridos Quirales Metal-Fullereno Se pretende evaluar la eficiencia de estos nuevos híbridos en reacciones fundamentales de transferencia de hidrógeno y su capacidad para ser reutilizados manteniendo la eficiencia. Selectividad en Fullerenos Superiores Se pretende desarrollar nuevas metodologías sintéticas basadas en condiciones suaves para obtener isómeros puros de [70]fullereno con un alto grado de selectividad. Reactividad Química en Fullerenos Endohédricos Síntesis de pirrolidinas enantioméricamente enriquecidas de HF@C60 y estudio del efecto que produce la mólecula de dentro en el proceso de isomerización cis-trans..., Fullerenes, firstly discovered by H. W. Kroto, R. F. Curl and R. E. Smalley in 1985, have received a great attention by the scientific community due to their remarkable electronic and photophysical properties, becoming one of the most intensively investigated molecules. Considering their unique properties derived from well-defined chemical constitution, fullerenes have emerged as promising materials for many potential applications. Objectives Synthesis of Chiral Metal/Fullerene Hybrids Design and synthesis of new chiral fullerene hybrids endowed with different metals, with a complete control over the new stereogenic centers, specifically with a metal-centered chirality. Catalytic Activity of Chiral Metal/Fullerene Hybrids Evaluate the efficiency of these new hybrid catalysts in fundamental hydrogen transfer reactions and the ability to be reused maintaining efficiency. Selectivity in Higher Fullerenes Development of new synthetic methodologies based on mild conditions for obtaining [70]fullerene derivatives with a high degree of selectivity. Chemical Reactivity on Endohedral Fullerenes Synthesis of enantiomerically enriched HF@C60 pyrrolidines and study of the effect of the incarcerated molecule on the cis-trans isomerization process...

Introducción El actual régimen energético, que se basa en fuentes de energía contaminantes no renovables, es insostenible desde los puntos de vista social, económico, geopolítico y ambiental. La única fuente totalmente renovable capaz de satisfacer la enorme y siempre creciente demanda energética del mundo es la energía solar. Las tecnologías fotovoltaicas, que convierten directamente la luz solar en electricidad, representan uno de los candidatos más prometedores para satisfacer esta demanda. Objetivos Capítulo 1: Desarrollo de moléculas pequeñas para células solares orgánicas. Capítulo 2: Desarrollo de moléculas pequeñas como materiales transportadores de huecos para células solares de perovskita. Resultados y discusión Capítulo 1. Moléculas pequeñas para células solares orgánicas i) Moléculas pequeñas A−D−A basadas en BDT-BTD Se han diseñado y sintetizado moléculas electroactivas que presentan una arquitectura de tipo A-D-A, la cual se emplea en algunos de los mejores fragmentos electrón dadores y aceptores encontrados en la literatura, concretamente, benzoditiofeno (BDT, como dador) y benzotiadiazol (BTD, como aceptor). Puentes tiofeno de longitud creciente han sido insertados entre los grupos aceptor y dador (Figura R1a), para mejorar la absorción y las propiedades de agregación. El estudio óptico, electroquímico y computacional ha revelado la naturaleza electroactiva de los compuestos y su habilidad para formar capas finas altamente ordenadas. Los dispositivos fotovoltaicos fabricados emplearon una mezcla de estos materiales con distintos derivados de fullereno como dador y aceptor, respectivamente, mostrando un comportamiento fotovoltaico pobre. El material con el mejor comportamiento (31) presentó una eficiencia de conversión energética (PCE) del 0.72% (Figura R1b)..., Introduction The current energetic regime, which relies on non-renewable polluting energy sources, is unsustainable from societal, economical, geopolitical, and environmental points of view. The only fully renewable source able to meet world’s huge and always growing energy demand is solar energy. Photovoltaic technologies, directly converting sunlight into electricity, represent one of the most promising candidates to meet this demand. Objectives Chapter 1: Development of new small molecules for organic solar cells (OSC). Chapter 2: Development of new small molecules as hole transporting materials (HTM) for perovskite solar cells. Results and Discussion Chapter 1. Small molecules for organic solar cells i) A−D−A Small molecules based on BDT-BTD Electroactive molecules featuring A−D−A architecture that employ some of the best performing electron donor and acceptor fragments found in the literature, namely benzodithiophene (BDT, as donor) and benzothiadiazole (BTD, as acceptor) have been designed and synthesized. Thiophene bridges of increasing length have been inserted in between A and D moieties (Figure S1a) in order to improve the absorption and aggregation properties. Optical, electrochemical and computational studies have revealed their electroactive nature and their ability to form well-ordered crystalline thin films. Photovoltaic devices employing these materials as donors in blends with fullerene derivatives showed poor performances, with best performing material (31) providing 0.72% PCE (Figure S1b)...

The infection of humans by lethal pathogens such as Ebola and other related viruses has not been properly addressed so far. In this context, a relevant question arises: what can chemistry do in the search for new strategies and approaches to solve this emergent problem? Although initially a variety of known chemical compounds – for other purposes – have been disappointingly tested against Ebola virus infection, more recently, specific molecules have been prepared. In this Perspective, we present a new approach directed to the design of efficient entry inhibitors to minimize the development of resistance by viral mutations. In particular, we focused on dendrimers as well as fullerene C60 – with a unique symmetrical and 3D globular structure – as biocompatible carbon platforms for the multivalent presentation of carbohydrates. The antiviral activity of these compounds in an Ebola pseudotyped infection model were in the low micromolar range for fullerenes with 12 and 36 mannoses. However, new tridecafullerenes – in which the central alkyne scaffold of [60]fullerene has been connected to 12 sugar-containing [60]fullerene units (total 120 mannoses)– exhibit an outstanding antiviral activity with IC50 in the subnanomolar range! The multivalent presentation of specific carbohydrates by using 3D fullerenes as controlled biocompatible carbon scaffolds represents a real advance being currently the most efficient molecules in vitro against Ebola virus infection. However, additional studies are needed to determine the optimized fullerene-based leads for practical applications., Ministerio de Economía, Comercio y Empresa (España), Instituto de Salud Carlos III, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Graphene is nowadays the most popular nanomaterial due to its excellentmechanical, electronic, and thermal properties. However, two major drawbackshamper its implementation in practical applications: its lack of solubility incommon solvents and its relative inert surface. To overcome such setbacks,both covalent and non-covalent chemical methods have been investigated inrecent years. The covalent functionalization results in stable products, butimplies the saturation of some of the double bonds affecting the electronicproperties of graphene, whereas the non-covalent functionalization allows itssolubilization while preserving the structural and electronic features.Within this general perspective, the main aim of this PhD work was to explorethe chemical modification of graphene with different electroactive moleculesthrough non-covalent interactions, specifically π-π stacking, which preservesthe π-conjugated system of graphene. We have prepared different molecularreceptors endowed with one (monopodal derivatives) or three pyrene units(tripodal derivatives), which favor the interactions between these systems andthe basal plane of graphene through π-π stacking interactions. In addition, thesereceptors have been decorated with different electroactive moieties (π-exTTF,porphyrins and C60), in order to modulate the electronic properties of graphene...