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51. Dibenzocycloheptatriene as end-group of Thiele and tetrabenzo-Chichibabin hydrocarbons

Author

Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, Generalitat de Catalunya, Swiss National Science Foundation, Jiménez, Vicente G., Mayorga, Paula, Blanco, Víctor, Lloveras, Vega, Gómez-García, Carlos J., Solomek, Tomás, Cuerva, Juan M., Veciana, Jaume, Campaña, Araceli G., Ministerio de Ciencia, Innovación y Universidades (España), European Research Council, Generalitat de Catalunya, Swiss National Science Foundation, Jiménez, Vicente G., Mayorga, Paula, Blanco, Víctor, Lloveras, Vega, Gómez-García, Carlos J., Solomek, Tomás, Cuerva, Juan M., Veciana, Jaume, and Campaña, Araceli G.

Abstract

Thiele (Th) and tetrabenzo-Chichibabin (TBC) derivatives with terminal dibenzocycloheptatriene (DBHept) units were prepared. A clear correlation between their electronic and molecular structures was stablished. Insights into their closed- or open-shell ground states were gained, where particular contribution of the heptagonal carbocycles as end-groups was proved. Remarkably, a thermally accessible triplet diradical configuration was confirmed for the DBHept-TBC compound.

Published
2020

55. Single‐Molecule Conductance of 1,4‐Azaborine Derivatives as Models of BN‐doped PAHs

Author

Palomino‐Ruiz, Lucía, primary, Rodríguez‐González, Sandra, additional, Fallaque, Joel G., additional, Márquez, Irene R., additional, Agraït, Nicolás, additional, Díaz, Cristina, additional, Leary, Edmund, additional, Cuerva, Juan M., additional, Campaña, Araceli G., additional, Martín, Fernando, additional, Millán, Alba, additional, and González, M. Teresa, additional

Published
2021
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56. Chimeric Drug Design with a Noncharged Carrier for Mitochondrial Delivery

Author

Ripoll, Consuelo, primary, Herrero-Foncubierta, Pilar, additional, Puente-Muñoz, Virginia, additional, Gonzalez-Garcia, M. Carmen, additional, Miguel, Delia, additional, Resa, Sandra, additional, Paredes, Jose M., additional, Ruedas-Rama, Maria J., additional, Garcia-Fernandez, Emilio, additional, Roldan, Mar, additional, Rocha, Susana, additional, De Keersmaecker, Herlinde, additional, Hofkens, Johan, additional, Martin, Miguel, additional, Cuerva, Juan M., additional, and Orte, Angel, additional

Published
2021
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57. Three-state molecular potentiometer based on a non-symmetrically positioned in-backbone linker

Author

Palomino-Ruiz, Lucía, primary, Reiné, Pablo, additional, R. Márquez, Irene, additional, Álvarez de Cienfuegos, Luis, additional, Agraït, Nicolás, additional, Cuerva, Juan M., additional, Campaña, Araceli G., additional, Leary, Edmund, additional, Miguel, Delia, additional, Millán, Alba, additional, Zotti, Linda A., additional, and González, M. Teresa, additional

Published
2021
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59. An enantiomeric pair of alkaline-earth metal based coordination polymers showing room temperature phosphorescence and circularly polarized luminescence

Author

Leo, Pedro, primary, Orcajo, Gisela, additional, García, Jose A., additional, Ortuño, Ana M., additional, Cuerva, Juan M., additional, Briones, David, additional, Calleja, Guillermo, additional, Rodríguez-Diéguez, Antonio, additional, Sanz, Raul, additional, Cepeda, Javier, additional, and Martínez, Fernando, additional

Published
2021
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61. General approach to polycyclic meroterpenoids based on Stille couplings and titanocene catalysts

Author

Justicia, Jose, Oltra, J. Enrique, Cuerva, Juan M., and Yaru Shi

Subjects
Olefins -- Research, Biological sciences, Chemistry
Abstract

A novel convergent procedure that has proved useful in the synthesis of a wide range of meroterpenoid-related structures containing a mono-, sesqui, or diterpenoid moiety linked to a nonfused aromatic subunit with various substitution patterns is discussed. The coupling reaction is perfectly compatible with preformed epoxides, while the sequential cyclixation provide exocyclic alkenes.

Published
2004

62. Effects of solvents and water in Ti(III)-mediated radical cyclizations of epoxygermacrolides. Straightforward synthesis and absolute stereochemistry of (+)-3alpha-hydroxyreynosin and related eudesmanolides

Author

Barrero, Alejandro F., Oltra, J. Enrique, Cuerva, Juan M., and Rosales, Antonio

Subjects
Chemistry, Organic -- Research, Ring formation (Chemistry) -- Physiological aspects, Titanium -- Physiological aspects, Water -- Physiological aspects, Solvents -- Physiological aspects, Macrolide antibiotics -- Physiological aspects, Epoxy compounds -- Physiological aspects, Biological sciences, Chemistry
Abstract

Research has been conducted on eudesmanolides which are the sequiterpene lactones' main skeletal types. The results of the straightforward synthesis of such eudesmanolides as (+)-3alpha-hydroxyreynosin and (+)-8beta-hydroxyasterolide carried out via different solvents and additives and containing exocyclic double bond are reported.

Published
2002

63. A new strategy for the synthesis of cyclic terpenoids based on the radical opening of acyclic epoxypolyenes

Author

Barrero, Alejandro F., Cuerva, Juan M., Herrador, M. M., and Valdivia, Monica V.

Subjects
Chemistry, Organic -- Research, Titanium compounds -- Research, Terpenes -- Research, Olefins -- Research, Biological sciences, Chemistry
Abstract

Research has been conducted on the oxabicyclic compounds. The application of a technique that involves the homolytic opening of epoxides with Ti(III) complexes to acyclic epoxypolyenes is discussed.

Published
2001

64. Chimeric Drug Design with a Noncharged Carrier for Mitochondrial Delivery

Author

Ripoll, Consuelo, primary, Herrero-Foncubierta, Pilar, additional, Puente-Muñoz, Virginia, additional, Gonzalez-Garcia, M. Carmen, additional, Miguel, Delia, additional, Resa, Sandra, additional, Paredes, Jose M., additional, Ruedas-Rama, Maria J., additional, Garcia-Fernandez, Emilio, additional, Martin, Miguel, additional, Roldan, Mar, additional, Rocha, Susana, additional, De Keersmaecker, Herlinde, additional, Hofkens, Johan, additional, Cuerva, Juan M., additional, and Orte, Angel, additional

Published
2020
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68. Innenrücktitelbild: Two‐Photon Absorption Enhancement by the Inclusion of a Tropone Ring in Distorted Nanographene Ribbons (Angew. Chem. 18/2020)

Author

Castro‐Fernández, Silvia, primary, Cruz, Carlos M., additional, Mariz, Inês F. A., additional, Márquez, Irene R., additional, Jiménez, Vicente G., additional, Palomino‐Ruiz, Lucía, additional, Cuerva, Juan M., additional, Maçôas, Ermelinda, additional, and Campaña, Araceli G., additional

Published
2020
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69. Inside Back Cover: Two‐Photon Absorption Enhancement by the Inclusion of a Tropone Ring in Distorted Nanographene Ribbons (Angew. Chem. Int. Ed. 18/2020)

Author

Castro‐Fernández, Silvia, primary, Cruz, Carlos M., additional, Mariz, Inês F. A., additional, Márquez, Irene R., additional, Jiménez, Vicente G., additional, Palomino‐Ruiz, Lucía, additional, Cuerva, Juan M., additional, Maçôas, Ermelinda, additional, and Campaña, Araceli G., additional

Published
2020
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72. Influence of thermally induced structural transformations on the magnetic and luminescence properties of tartrate-based chiral lanthanide organic-frameworks

Author

Huizi-Rayo, Uxua, primary, Zabala-Lekuona, Andoni, additional, Terenzi, Alessio, additional, Cruz, Carlos M., additional, Cuerva, Juan M., additional, Rodríguez-Diéguez, Antonio, additional, García, Jose Angel, additional, Seco, José M., additional, San Sebastian, Eider, additional, and Cepeda, Javier, additional

Published
2020
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73. Asymmetric Reduction of Ketones

Author

Dubrovina, Natalia, primary, Börner, Armin, additional, Nakamura, Kaoru, additional, Fujii, Mikio, additional, Ida, Yoshiteru, additional, Rosales, Antonio, additional, Cuerva, Juan M., additional, Oltra, J. Enrique, additional, Moran, Paul H., additional, Henschke, Julian P., additional, Zanotti-Gerosa, Antonio, additional, Lennon, Ian C., additional, Stephan, Michel Massoud S., additional, Mohar, Barbara, additional, Wills, Martin, additional, Xu, Yingjian, additional, Docherty, Gorden, additional, Woodward, Gary, additional, Wettergren, Jenny, additional, Adolfsson, Hans, additional, Jeulin, Séverine, additional, Ratovelomanana-Vidal, Virginie, additional, Genet, Jean-Pierre, additional, Burri, Estelle, additional, Wendicke, Silke B., additional, Severin, Kay, additional, Guo, Minjie, additional, Li, Dao, additional, Sun, Yanhui, additional, Zhang, Zhaoguo, additional, Chai, Liting, additional, Li, Yangzhou, additional, Wang, Quanrui, additional, Wang, Guangyin, additional, and Zhao, Gang, additional

Published
2007
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74. Cyclisation Reactions

Author

Blanco-Urgoiti, Jaime, primary, Domínguez, Gema, additional, Pérez-Castells, Javier, additional, Zhao, Ligang, additional, Lu, Xiyan, additional, He, Minsheng, additional, Lei, Aiwen, additional, Zhang, Xumu, additional, Shinokubo, Hiroshi, additional, Oshima, Koichiro, additional, Rosales, Antonio, additional, Cuerva, Juan M., additional, and Oltra, Enrique, additional

Published
2005
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75. Enantiopure Double ortho‐Oligophenylethynylene‐Based Helical Structures with Circularly Polarized Luminescence Activity.

Author

Reiné, Pablo, Ortuño, Ana M., Resa, Sandra, Álvarez de Cienfuegos, Luis, Ribagorda, María, Mota, Antonio J., Abbate, Sergio, Longhi, Giovanna, Miguel, Delia, and Cuerva, Juan M.

Subjects
HELICAL structure, LUMINESCENCE, CIRCULAR dichroism, ZINC catalysts, COORDINATION polymers, OPTICAL properties, ISOMERS
Abstract

In this paper, we describe the optical and chiroptical properties of an enantiopure multipodal ortho‐oligophenylethynylene (S,S,S,S)‐1 presenting four chiral sulfoxide groups at the extremes. The presence of these groups together with alkynes allows the coordination with carbophilic Ag(I), and/or oxophilic Zn(II) cations, yielding double helical structures in an enantiopure way. In this sense, different behaviors in absorption, fluorescence, ECD and CPL spectra have been found depending on the stoichiometry and nature of the metal. We have observed that Zn(II) coordination favors an intensity increase of the electronic circular dichroism (ECD) spectra of compound (S,S,S,S)‐1 yielding an M‐helicity in the ortho‐oligophenylene ethynylene (o‐OPE) backbone. On the other hand, ECD spectra of final Ag(I) complex shows two different bands with an opposite sign to the free ligand, thus giving the P‐helical isomer. In addition, circularly polarized luminescence (CPL) exhibit an enhanced intensity and negative sign in both complexes. Computational studies were also carried out, supporting the experimental results. [ABSTRACT FROM AUTHOR]

Published
2022
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76. Michael reaction of stabilized carbon nucleophiles catalyzed by RuH2(PPh3)4

Author

Gomez-Bengoa, Enrique, Cuerva, Juan M., Mateo, Cristina, and Echavarren, Antonio M.

Subjects
Chemical reactions -- Research, Ruthenium -- Analysis, Complex compounds -- Analysis, Catalysis -- Research, Chemistry
Abstract

The ruthenium complex RuH2(PPh3)4 is an excellent catalyst for the Michael addition of active methylene compounds lacking cyano groups when the reactions are performed in acetonitrile instead of THF. The reaction proceeds satisfactorily in acetonitrile under mild and neutral conditions with malonates, beta-ketoesters, 1,3-diketones, 1,1-disulfones, nitro compounds, Meldrum acid and anthrone as the Michael donors. Cyano acetates can also be ideal substrates for this reaction.

Published
1996

77. O-H and (CO)N-H bond weakening by coordination to Fe(ii)

Author

Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Commission, Consejo Superior de Investigaciones Científicas (España), Resa, Sandra, Millán, Alba, Fuentes, Noelia, Crovetto, Luis, Marcos, María-Luisa, Lezama, Luis, Choquesillo-Lazarte, Duane, Blanco, Víctor, Campaña, Araceli G., Cárdenas, D. J., Cuerva, Juan M., Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Commission, Consejo Superior de Investigaciones Científicas (España), Resa, Sandra, Millán, Alba, Fuentes, Noelia, Crovetto, Luis, Marcos, María-Luisa, Lezama, Luis, Choquesillo-Lazarte, Duane, Blanco, Víctor, Campaña, Araceli G., Cárdenas, D. J., and Cuerva, Juan M.

Abstract

New N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)-ethane-1,2-diamine derivatives bearing covalently linked OH and (CO)NH groups have been synthesized. The coordination of those pendant hydroxyl/amide groups to a Fe(ii) metal center is demonstrated both in solution, even in the presence of chloride as the counterion, and in solid state, by means of X-ray diffraction crystal structures. As a result of this coordination, the experimental bond dissociation free energies (BDFE) of O-H and (CO)N-H bonds are remarkably diminished down to 76.0 and 80.5 kcal mol respectively, which is also in agreement with DFT-based theoretical calculations. These BDFE values are in the range of commonly used hydrogen-atom donor reagents. The strategy presented here allows an unequivocal evaluation of the influence of metal coordination in X-H bond weakening in organic solvents which could be easily extended to other metal centers.

Published
2019

78. Enhanced Stability against Radiation Damage of Lysozyme Crystals Grown in Fmoc-CF Hydrogels

Author

Ministerio de Economía, Industria y Competitividad (España), Agencia Estatal de Investigación (España), European Commission, Junta de Andalucía, Contreras Montoya, Rafael, Castellví, Albert, Escolano-Casado, Guillermo, Juanhuix, Judith, Conejero Muriel, Mayte, López López, Modesto, Cuerva, Juan M., Álvarez de Cienfuegos, Luis, Gavira Gallardo, J. A., Ministerio de Economía, Industria y Competitividad (España), Agencia Estatal de Investigación (España), European Commission, Junta de Andalucía, Contreras Montoya, Rafael, Castellví, Albert, Escolano-Casado, Guillermo, Juanhuix, Judith, Conejero Muriel, Mayte, López López, Modesto, Cuerva, Juan M., Álvarez de Cienfuegos, Luis, and Gavira Gallardo, J. A.

Abstract

Lysozyme crystals grown in Fmoc-CF (Cys-Phe) hydrogels, unlike those grown in agarose, give rise to composite crystals that have an enhanced resistance against degradation caused by an intense exposure to X-ray irradiation. Fmoc-CF dipeptide shows a clear protection of the most sensitive groups (disulfide bonds and methionines) of the protein. The protection mediated by cysteine is exerted only in its gel state since cysteine in solution has an adverse effect. Probably, the reactive thiol groups of cysteine being locked within the rigid peptide fibers minimize cross-reactions with the proteins favoring the formation of protein crystals. Once located inside the protein crystal, the long peptide fibers are able to protect the protein against radiation damage. ©

Published
2019

79. Palladium-catalyzed reductive coupling of acid chlorides with beta-stannyl enones: synthesis of 1,4-diketones and mechanistic aspects

Author

Echavarren, Antonio M., Perez, Marta, Castano, Ana M., and Cuerva, Juan M.

Subjects
Ketones -- Analysis, Chlorides -- Analysis, Oxidation-reduction reaction -- Analysis, Palladium catalysts -- Analysis, Biological sciences, Chemistry
Abstract

Palladium catalyzes coupling reactions between acid chlorides and E-(1,2)-bis(tri-n-butylstannyl)ethene or beta-stannyl enones to produce butane-1,4-diones. The reaction involves reduction of an enedicarbonyl intermediate. Coupling reactions at low temperatures yield alpha, beta-unsaturated 1,4-diketones, and involve palladium hydride-promoted reduction. This method facilitates synthesis of two 1,4-diketone ipomeanines.

Published
1994

80. Stapled helical o-OPE foldamers as new circularly polarized luminescence emitters based on carbophilic interactions with Ag(i)-sensitivity† †We dedicate this work to Ettore Castiglioni who, with his high experience in the field of chiroptical spectroscopies, gave important contributions also to the development of CPL instrumentation. ‡ ‡Electronic supplementary information (ESI) available: general experimental details, synthesis of all new substrates and complexes, 1H and 13C NMR spectra of the new compounds and the corresponding NMR titrations, photophysical and theoretical data. CCDC 1443131. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc01808d

Author

Morcillo, Sara P., Miguel, Delia, Álvarez de Cienfuegos, Luis, Justicia, José, Abbate, Sergio, Castiglioni, Ettore, Bour, Christophe, Ribagorda, María, Cárdenas, Diego J., Paredes, José Manuel, Crovetto, Luis, Choquesillo-Lazarte, Duane, Mota, Antonio J., Carreño, M. Carmen, Longhi, Giovanna, and Cuerva, Juan M.

Subjects
Chemistry
Abstract

Chiral stapled o-OPEs show excellent circular polarized luminescence responses (glum of 1.1 × 10–2) which can be modulated by carbophilic interactions., ortho-Oligo(phenylene)ethynylenes (o-OPEs) stapled with enantiopure 2,3-dihydroxybutane diethers have highly intense circular dichroism (CD) spectra and excellent circular polarized luminescence (CPL) responses (glum values up to 1.1 × 10–2), which are consistent with homochiral helically folded structures. In the presence of Ag(i), a change in the CPL emission is observed, representing the first example of CPL active small organic molecular emitters, which can be modulated by carbophilic interactions in a reversible manner.

Published
2016

81. Central incisors shape and proportions prevalence in Argentinian university students: by visual assessment and a new standardized method.

Author

Trigo-Humaran, María M., Agüero-Romero, Alan B., Lespade, Marcela, García-Cuerva, Juan M., and Iglesias, María E.

Subjects
INCISORS, COLLEGE students, ALGORITHMS, DIGITAL images, DENTAL education, TEETH
Abstract

Copyright of Acta Odontologica Latinoamericana: AOL is the property of Acta Odontologica Latinoamericana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2021
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82. Titelbild: Enantiopure [6]‐Azairidahelicene by Dynamic Kinetic Resolution of a Configurationally Labile [4]‐Helicene (Angew. Chem. 26/2024).

Author

Pazos, Ariadna, Cruz, Carlos M., Cuerva, Juan M., Rivilla, Ivan, Cossío, Fernando P., and Freixa, Zoraida

Subjects
CIRCULAR dichroism, CHIRAL centers, PHOSPHORESCENCE, ENERGY storage, PALLADIUM
Abstract

This document, published in the journal Angewandte Chemie, highlights several research findings in the field of chemistry. One study discusses the synthesis of enantiopure irida[6]helicenes, which exhibit mirrored electronic circular dichroism and circularly polarized phosphorescence signals. Another study explores the use of the CF3 group as a synthon in palladium chemistry. Additionally, researchers demonstrate a selective shift in energy storage mechanism in aqueous aluminum-ion batteries through the engineering of oxygen vacancies in the α-MoO3 structure. Lastly, a scientific perspective proposes a unified set of triple E priorities (environment, economy, equity) to guide efforts in sustainable chemistry. [Extracted from the article]

Published
2024
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89. O–H and (CO)N–H bond weakening by coordination to Fe(ii)

Author

Resa, Sandra, primary, Millán, Alba, additional, Fuentes, Noelia, additional, Crovetto, Luis, additional, Luisa Marcos, M., additional, Lezama, Luis, additional, Choquesillo-Lazarte, Duane, additional, Blanco, Victor, additional, Campaña, Araceli G., additional, Cárdenas, Diego J., additional, and Cuerva, Juan M., additional

Published
2019
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92. Catalytic and Electron Conducting Carbon Nanotube–Reinforced Lysozyme Crystals

Author

Ministerio de Economía, Industria y Competitividad (España), Agencia Estatal de Investigación (España), Junta de Andalucía, Universidad de Granada, Contreras Montoya, Rafael, Escolano, Gillermo, Roy, Subhasish, López López, Modesto, Delgado López, José Manuel, Cuerva, Juan M., Díaz Mochón, Juan José, Ashkenasy, Nurit, Gavira Gallardo, J. A., Álvarez de Cienfuegos, Luis, Ministerio de Economía, Industria y Competitividad (España), Agencia Estatal de Investigación (España), Junta de Andalucía, Universidad de Granada, Contreras Montoya, Rafael, Escolano, Gillermo, Roy, Subhasish, López López, Modesto, Delgado López, José Manuel, Cuerva, Juan M., Díaz Mochón, Juan José, Ashkenasy, Nurit, Gavira Gallardo, J. A., and Álvarez de Cienfuegos, Luis

Abstract

Novel reinforced cross-linked lysozyme crystals containing homogeneous dispersions of single-walled carbon nanotubes bundles (SWCNTs) are produced and characterized. The incorporation of SWCNTs inside lysozyme crystals gives rise to reinforced composite materials with tunable mechanical strength and electronic conductivity, while preserving the crystal quality and morphology. These reinforced crystals show increased catalytic activity at higher temperatures, being active even above the denaturation temperature. The electron transport through the crystals is linked to the content and distribution of SWCNT bundles inside the crystals. The electron conduction through the crystals is isotropic and very efficient, presenting high conductivity values up to 600 nS at very low (0.05 wt%) SWCNT concentration. To obtain these crystals, a new protocol based on the in situ crystallization of lysozyme in composite SWCNT–peptide hydrogels is developed. These peptide hydrogels are able to homogeneously disperse bundles of hydrophobic SWCNTs allowing first, the crystallization of the enzyme lysozyme and second, transferring the new properties of the inorganic component to the crystals. Taken together, these composite crystals represent an example of the versatility of proteins as biological substrates in the generation of novel functional materials, opening the door to use them in catalysis and bioelectronics at macroscale.

Published
2018

93. Enantiopure distorted ribbon-shaped nanographene combining two-photon absorption-based upconversion and circularly polarized luminescence

Author

European Research Council, Ministerio de Economía y Competitividad (España), Fundação para a Ciência e a Tecnologia (Portugal), Cruz, Carlos M., Márquez, Irene R., Mariz, Inês F. A., Blanco, Víctor, Sánchez-Sánchez, Carlos, Sobrado, Jesús Manuel, Martín-Gago, José A., Cuerva, Juan M., Maçôas, Ermelinda, Campaña, Araceli G., European Research Council, Ministerio de Economía y Competitividad (España), Fundação para a Ciência e a Tecnologia (Portugal), Cruz, Carlos M., Márquez, Irene R., Mariz, Inês F. A., Blanco, Víctor, Sánchez-Sánchez, Carlos, Sobrado, Jesús Manuel, Martín-Gago, José A., Cuerva, Juan M., Maçôas, Ermelinda, and Campaña, Araceli G.

Abstract

Herein we describe a distorted ribbon-shaped nanographene exhibiting unprecedented combination of optical properties in graphene-related materials, namely upconversion based on two-photon absorption (TPA-UC) together with circularly polarized luminescence (CPL). The compound is a graphene molecule of ca. 2 nm length and 1 nm width with edge defects that promote the distortion of the otherwise planar lattice. The edge defects are an aromatic saddle-shaped ketone unit and a [5]carbohelicene moiety. This system is shown to combine two-photon absorption and circularly polarized luminescence and a remarkably long emission lifetime of 21.5 ns. The [5]helicene is responsible for the chiroptical activity while the push–pull geometry and the extended network of sp2 carbons are factors favoring the nonlinear absorption. Electronic structure theoretical calculations support the interpretation of the results.

Published
2018

94. Iron nanoparticles-based supramolecular hydrogels to originate anisotropic hybrid materials with enhanced mechanical strength

Author

Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Junta de Andalucía, European Commission, Contreras-Montoya, Rafael, Bonhome-Espinosa, Ana B., Orte, Angel, Miguel, Delia, Delgado-López, José M., Durán, Juan G. D., Cuerva, Juan M., Lopez-Lopez, Modesto T., Cienfuegos, Luis Álvarez de, Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Junta de Andalucía, European Commission, Contreras-Montoya, Rafael, Bonhome-Espinosa, Ana B., Orte, Angel, Miguel, Delia, Delgado-López, José M., Durán, Juan G. D., Cuerva, Juan M., Lopez-Lopez, Modesto T., and Cienfuegos, Luis Álvarez de

Abstract

Here, we report the synthesis and structural characterization of novel iron nanoparticles (FeNPs)-based short-peptide supramolecular hydrogels. These hybrid hydrogels composed of Fmoc-diphenylalanine (Fmoc-FF) peptide and FeNPs were prepared through the self-assembly of Fmoc-FF in a suspension containing FeNPs in the presence or absence of an external magnetic field. Optical images of these hydrogels revealed the formation of column-like aggregates of FeNPs when the gels were formed in the presence of a magnetic field. Moreover, the intricate structure derived from the interwoven nature of the fiber peptides with these FeNP column-like aggregates resulted in anisotropic materials, more rigid under shear forces applied perpendicularly to the direction of the aggregates, presenting under these conditions values of G0 (storage modulus) about 7 times those of the native hydrogel. To the best of our knowledge, this is the first example in which the mechanical properties of peptide hydrogels were strongly enhanced due to the presence of FeNPs. A theoretical model trying to explain this phenomenon is presented. Quite interesting CD, FTIR and synchrotron X-ray diffraction analyses indicated that the anti-parallel b-sheet arrangement of Fmoc-FF peptide was highly conserved in the hydrogels containing FeNPs. Moreover, FLCS measurements showed that the diffusion of a small solute through the hydrogel network was improved in hydrogels containing FeNPs, probably caused by the formation of preferential channels for diffusion. Taken together, our results provide a new method for the synthesis of novel hybrid Fmoc-FF-FeNPs anisotropic hydrogels with enhanced mechanical strength and water-like diffusion behavior, thus easing their application in drug delivery and tissue engineering

Published
2018

95. Sulfoxide-Induced Homochiral Folding of ortho-Phenylene Ethynylenes (o-OPEs) by Silver(I) Templating: Structure and Chiroptical Properties

Author

Ministerio de Economía y Competitividad (España), Ministerio de Educación, Cultura y Deporte (España), Resa, Sandra, Miguel, Delia, Guisán-Ceinos, Santiago, Mazzeo, Giuseppe, Choquesillo-Lazarte, Duane, Abbate, Sergio, Crovetto, Luis, Cárdenas, D. J., Carreño, M. C., Ribagorda, María, Longhi, Giovanna, Mota, Antonio J., Cienfuegos, Luis Álvarez de, Cuerva, Juan M., Ministerio de Economía y Competitividad (España), Ministerio de Educación, Cultura y Deporte (España), Resa, Sandra, Miguel, Delia, Guisán-Ceinos, Santiago, Mazzeo, Giuseppe, Choquesillo-Lazarte, Duane, Abbate, Sergio, Crovetto, Luis, Cárdenas, D. J., Carreño, M. C., Ribagorda, María, Longhi, Giovanna, Mota, Antonio J., Cienfuegos, Luis Álvarez de, and Cuerva, Juan M.

Abstract

A new family of homochiral silver complexes based on carbophilic interactions with ortho-phenylene ethynylene (o-OPE) scaffolds containing up to two silver atoms are described. These compounds represent a unique class of complexes with chirality at the metal. Chiral induction is based on the inclusion of chiral sulfoxides, which allow efficient transfer of chirality to the helically folded o-OPE, leading to circularly polarized luminescence (CPL)- and vibrational circular dichroism (VCD)-active compounds. In the presence of silver(I) cations, carbophilic interactions dominate, which promote helical structures with a defined helicity. This is one of the very scarce examples of the use of such interactions in the attractive field of abiotic foldamers. The switching event has been extensively studied by using different chiroptical techniques, including circular dichroism, CPL, and VCD, and represents one of the few CPL switches described in the literature.

Published
2018

96. Catalytic and Electron Conducting Carbon Nanotube–Reinforced Lysozyme Crystals

Author

Contreras‐Montoya, Rafael, primary, Escolano, Guillermo, additional, Roy, Subhasish, additional, Lopez‐Lopez, Modesto T., additional, Delgado‐López, Jose M., additional, Cuerva, Juan M., additional, Díaz‐Mochón, Juan J., additional, Ashkenasy, Nurit, additional, Gavira, José A., additional, and Álvarez de Cienfuegos, Luis, additional

Published
2018
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99. Pyrene-Containing ortho-Oligo(phenylene)ethynylene Foldamer as a Ratiometric Probe Based on Circularly Polarized Luminescence

Author

Reiné, Pablo, primary, Justicia, Jose, additional, Morcillo, Sara P., additional, Abbate, Sergio, additional, Vaz, Belen, additional, Ribagorda, María, additional, Orte, Ángel, additional, Álvarez de Cienfuegos, Luis, additional, Longhi, Giovanna, additional, Campaña, Araceli G., additional, Miguel, Delia, additional, and Cuerva, Juan M., additional

Published
2018
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100. Sulfoxide-Induced Homochiral Folding of ortho -Phenylene Ethynylenes (o -OPEs) by Silver(I) Templating: Structure and Chiroptical Properties

Author

Resa, Sandra, primary, Miguel, Delia, additional, Guisán-Ceinos, Santiago, additional, Mazzeo, Giuseppe, additional, Choquesillo-Lazarte, Duane, additional, Abbate, Sergio, additional, Crovetto, Luis, additional, Cárdenas, Diego J., additional, Carreño, M. Carmen, additional, Ribagorda, María, additional, Longhi, Giovanna, additional, Mota, Antonio J., additional, Álvarez de Cienfuegos, Luis, additional, and Cuerva, Juan M., additional

Published
2018
Full Text
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