Self-assembly of bent-core amphiphiles joining the ethylene-oxide/lithium ion tandem

The synthesis, supramolecular self-assembly and structural characterization of a new family of tetraethylene oxide (TEG)-based bent-core compounds and their 1/1 lithium-containing complexes are reported. TEG-based bent-core amphiphiles, even joining the TEG/Li+ tandem, are suitable building-blocks to achieve supramolecular nanostructures, in some cases showing chiral features from achiral molecules either in the mesophase or in solvents. The thermal and liquid crystal behavior of these materials studied by polarizing optical microscopy and X-ray diffraction confirmed that Li-based materials stabilized polar smectic C and helical nanofilament-type mesophases, in contrast to the non-liquid crystalline pure TEG-compounds. Alternatively, both the pure amphiphiles and the lithium-doped materials self-assemble into physical gels in non-polar solvents, displaying three-dimensional networks composed of long fibers with lamellar molecular organizations as shown by transmission electron microscopy and X-ray diffraction. Interestingly, biphenyl- and azobenzene-based bent core amphiphiles aggregate in solvent into chiral nanostructured morphologies with supramolecular trends comparable to their molecular arrangement in their liquid crystalline phases

Organizaciones supramoleculares de moléculas dendríticas con estructuras tipo "Bent-Core"

Resumen del póster presentado a la 6ª Jornada de Jóvenes Investigadores en Física y Química de Aragón celebrada en Zaragoza el 20 de noviembre de 2014.Beca de Colaboración del MEC y Beca de Iniciación a la Investigación del INA (A. M. B-S), Beca JAE-Predoc (M. M-A), Beca FPI (A. C.). Grupo de Cristales Líquidos y Polímeros: proyectos MAT2012-38538-CO3-01 y CTQ2012-35692 (MINECO-FEDER) y E04 (Gobierno de Aragón).Peer reviewe

Condiciones habitacionales y urbanísticas de la población inmigrada en la Región Metropolitana de Barcelona

En la última década tanto las ciudades catalanas como las del resto del Estado Español, han sufrido importantes modificaciones en su morfología física y social debido a la llegada de numerosa población inmigrante. Esta población se localiza en unas zonas determinadas de nuestras ciudades y tiene unos patrones de asentamiento residencial diferentes a los de la población nativa. Asimismo, las características de sus viviendas y el uso que hacen del espacio público son diferentes a los del resto de la población. En esta ponencia se profundizará en el uso que hace la población inmigrante del espacio público en la Región Metropolitana de Barcelona, qué espacios públicos y qué equipamientos utilizan y si estos se ajustan a sus necesidades cotidianas; qué variables tienen mayor incidencia en este uso (edad, género, procedencia); como interactúa esta población con el resto de población del barrio; qué tipo de usos hacen del espacio público; cómo se relacionan la configuración física y social del espacio….Asimismo, se intentará detallar más escuetamente cuáles son las características habitacionales de esta población: cómo son sus casas y cómo acceden a ella. El ámbito territorial de la investigación es la Región Metropolitana de Barcelona. La investigación se desarrolla en distintos barrios de la RMB con diferentes características urbanísticas y demográficas, pero que tienen en común que cuentan con una concentración de población inmigrante superior a la media de la RMB. La metodología empleada es una combinación de técnicas cuantitativas y cualitativas.In the last decade both the Catalan cities as the rest of Spain, has undergone major changes in their physical and social morphology due to the arrival of large immigrant populations. This population is located in specific areas of our cities and has a residential settlement patterns different from the native population. Furthermore, the characteristics of their homes and their use of public space are different from the rest of the population. This paper will delve into the use by the immigrant population of public space in the metropolitan area of Barcelona, what public spaces and what equipment they use and if they fit their daily needs, what variables have the greatest impact in this application (age, gender, origin), as this population interacts with the rest of the neighborhood population, and what kinds of uses made of public space, and how are the physical and social space .... It will try to detail more succinctly what characteristics housing for this population: how are their homes and how to access it. The territorial scope of the research is the metropolitan area of Barcelona. The research is conducted in different districts of the RMB with different urban and demographic characteristics, but they have in common that have a concentration of immigrant population than the average of the RMB. The methodology is a combination of quantitative and qualitative.Peer Reviewe

Liquid crystalline and nonlinear optical properties of bent-shaped compounds derived from 3,49-biphenylene.

9 pages, 6 figures, 3 tables.The synthesis of different bent-core molecules derived from 3,49-biphenylene bearing azo, azoxy, imine or ester linkages in their lateral structures is reported. Structure–activity relationships for their liquid crystalline behaviour are discussed. SmCP, USmCP and Colob mesophases are found depending on the type and number of these connecting units. The sequence ester#azoxy . imine . azo can be proposed for the mesophase range, with significant differences observed in terms of mesopahase stabilization. SHG studies on these compounds give nonlinear coefficients in the range of 1–8 pm V21. The molecular origin for these values is analyzed semi- uantitatively. It was concluded that the SHG performance of bent-core mesogens in general can still be increased substantially. An approach to improve the properties of these materials is briefly outlined.This work was supported by projects MAT2003-07806-C02 and MAT2006-13571-C02 (CICYT-FEDER) from Spain-EU and by the DGA (Spain) and University of the Basque Country (Project. Nu 9/UPV 00060.310-13562/2001). I. P. and I. A. also thank DGA and the Ministry of Education of Spain, respectively, for grants.Peer reviewe

Twist, tilt, and orientational order at the nematic to twist-bend nematic phase transition of 1″,9″-bis(4-cyanobiphenyl-4′-yl) nonane: A dielectric, 2H NMR, and calorimetric study

Under the terms of the Creative Commons Attribution license.-- et al.The nature of the nematic-nematic phase transition in the liquid crystal dimer 1″,9″-bis(4-cyanobiphenyl-4′-yl) nonane (CB9CB) has been investigated using techniques of calorimetry, dynamic dielectric response measurements, and H2 NMR spectroscopy. The experimental results for CB9CB show that, like the shorter homologue CB7CB, the studied material exhibits a normal nematic phase, which on cooling undergoes a transition to the twist-bend nematic phase (NTB), a uniaxial nematic phase, promoted by the average bent molecular shape, in which the director tilts and precesses describing a conical helix. Modulated differential scanning calorimetry has been used to analyze the nature of the NTB-N phase transition, which is found to be weakly first order, but close to tricritical. Additionally broadband dielectric spectroscopy and H2 magnetic resonance studies have revealed information on the structural characteristics of the recently discovered twist-bend nematic phase. Analysis of the dynamic dielectric response in both nematic phases has provided an estimate of the conical angle of the heliconical structure for the NTB phase. Capacitance measurements of the electric-field realignment of the director in initially planar aligned cells have yielded values for the splay and bend elastic constants in the high temperature nematic phase. The bend elastic constant is small and decreases with decreasing temperature as the twist-bend phase is approached. This behavior is expected theoretically and has been observed in materials that form the twist-bend nematic phase. H2 NMR measurements characterize the chiral helical twist identified in the twist-bend nematic phase and also allow the determination of the temperature dependence of the conical angle and the orientational order parameter with respect to the director.The authors are grateful for financial support from the MICINN project MAT2012-38538-C03-02,03 and from the Eusko Jaurlaritza-Gobierno Vasco (GI/IT-449-10). The authors also acknowledge the recognition from the Generalitat de Catalunya of GRPFM as Emergent Research Group (2009-SGR-1243). N.S. thanks the Alexander von Humboldt Foundation for a Postdoctoral Research Fellowship.Peer Reviewe

Bent-core liquid crystals joining the ethylene-oxide/lithium ion tandem: Ionic conductivity and dielectric response towards new electrolytes for energy applications

We report the dielectric and conductivity response of three materials containing bent-core and tetra(ethylene-oxide) moieties, and their complexes doped with lithium triflate salts, as new potential nanostructured electrolytes. Whilst the pristine bent-core compounds do not show mesomorphism, the doped materials display smectic mesophases inside indium tin oxide cells assisted by the selective solvation of the lithium ions in the ethylene-oxide blocks. The dielectric response of the materials in the high-frequency range is controlled by the chemical composition of the bent-core structure, and the presence of lithium ions promotes direct current conductivity at low frequencies, in the σdc ∼ 10-5 S cm−1 range, which can be enhanced to σdc ∼ 10-4 S cm−1 via trans-to-cis photoisomerization of azobenzene groups. The dynamic and dual character of these materials (responding to low and high frequency electrical fields), the formation of ferroelectric crystals capable to store energy, and their interactions with light, will be applied to develop new energy devices

Fluoroquinolone photodegradation influences specific basophil activation

Fluoroquinolones (FQs) are photoreactive drugs, but it is not known whether laboratory light exposure can influence the induction of photoproducts and modify in vitro test results. The basophil activation test (BAT) has proven to be useful for evaluating immunoglobulin E (IgE)-mediated hypersensitivity to FQs, with a higher percentage of positive responders with ciprofloxacin (CIP) than with moxifloxacin (MOX). We studied the effect of laboratory light on CIP and MOX degradation, and drug-protein conjugate formation, and its influence on the BAT for evaluating IgE-mediated hypersensitivity to FQs. The results showed an important decrease in fluorescence emission intensity under light compared to dark conditions for MOX, and that BAT positivity was lower in light (17.9%) than in dark (35.7%) conditions. No changes were found for CIP in either fluorescence emission intensity or BAT results (46.4% in both conditions). We can conclude that light exposure is a critical factor in BAT results when photolabile drugs like MOX are used. Therefore, light is important when interpreting in vitro results. Copyright (C) 2012 S. Karger AG, BaselWe thank Ian Johnstone for his help with the English language version of the manuscript, and Jose Luis Rodriguez-Bada and Lidia Melendez for their technical support. This study was funded by the FIS-Thematic Networks and Co-operative Research Centres: RIRAAF (RD07/0064) and the Spanish Health Ministry (FIS PS09/01768, PI11/01416 and M Servet contract CP11/00154 for I.A.), the Andalusia Health Ministry (PI-0545-2010), and the Andalusia Economic Innovation and Science Ministry (CTS 06603).Mayorga, C.; Andreu Ros, MI.; Aranda, A.; Doña, I.; Montañez, MI.; Blanca-López, N.; Ariza, A.... (2013). Fluoroquinolone photodegradation influences specific basophil activation. International Archives of Allergy and Immunology. 160(4):377-382. https://doi.org/10.1159/000343023S3773821604Albini, A., & Monti, S. (2003). Photophysics and photochemistry of fluoroquinolones. Chemical Society Reviews, 32(4), 238. doi:10.1039/b209220bBelvedere, A., Boscá, F., Cuquerella, M. C., de Guidi, G., & Miranda, M. A. (2002). Photoinduced N-Demethylation of Rufloxacin and its Methyl Ester Under Aerobic Conditions¶. Photochemistry and Photobiology, 76(3), 252. doi:10.1562/0031-8655(2002)0762.0.co;2Dawe, R. S., Ibbotson, S. H., Sanderson, J. B., Thomson, E. M., & Ferguson, J. (2003). A randomized controlled trial (volunteer study) of sitafloxacin, enoxacin, levofloxacin and sparfloxacin phototoxicity. British Journal of Dermatology, 149(6), 1232-1241. doi:10.1111/j.1365-2133.2003.05582.xHayashi, N., Nakata, Y., & Yazaki, A. (2004). New Findings on the Structure-Phototoxicity Relationship and Photostability of Fluoroquinolones with Various Substituents at Position 1. Antimicrobial Agents and Chemotherapy, 48(3), 799-803. doi:10.1128/aac.48.3.799-803.2004Van Bambeke, F., & Tulkens, P. M. (2009). Safety Profile of the Respiratory Fluoroquinolone Moxifloxacin. Drug Safety, 32(5), 359-378. doi:10.2165/00002018-200932050-00001Sachs, B., Riegel, S., Seebeck, J., Beier, R., Schichler, D., Barger, A., … Erdmann, S. (2006). Fluoroquinolone-Associated Anaphylaxis in Spontaneous Adverse Drug Reaction Reports in Germany. Drug Safety, 29(11), 1087-1100. doi:10.2165/00002018-200629110-00008Manfredi, M., Severino, M., Testi, S., Macchia, D., Ermini, G., Pichler, W. J., & Campi, P. (2004). Detection of specific IgE to quinolones. Journal of Allergy and Clinical Immunology, 113(1), 155-160. doi:10.1016/j.jaci.2003.09.035Aranda, A., Mayorga, C., Ariza, A., Doña, I., Rosado, A., Blanca-Lopez, N., … Torres, M. J. (2010). In vitro evaluation of IgE-mediated hypersensitivity reactions to quinolones. Allergy, 66(2), 247-254. doi:10.1111/j.1398-9995.2010.02460.xAndreu, I., Mayorga, C., & Miranda, M. A. (2010). Generation of reactive intermediates in photoallergic dermatitis. Current Opinion in Allergy and Clinical Immunology, 10(4), 303-308. doi:10.1097/aci.0b013e32833bc68cAntunez, C., Fernandez, T., Blanca-Lopez, N., Torres, M. J., Mayorga, C., Canto, G., … Blanca, M. (2006). IgE antibodies to betalactams: relationship between the triggering hapten and the specificity of the immune response. Allergy, 61(8), 940-946. doi:10.1111/j.1398-9995.2006.01120.xTorres, M. J., Ariza, A., Mayorga, C., Doña, I., Blanca-Lopez, N., Rondon, C., & Blanca, M. (2010). Clavulanic acid can be the component in amoxicillin-clavulanic acid responsible for immediate hypersensitivity reactions. Journal of Allergy and Clinical Immunology, 125(2), 502-505.e2. doi:10.1016/j.jaci.2009.11.032Torres, M. J., & Blanca, M. (2010). The Complex Clinical Picture of β-Lactam Hypersensitivity: Penicillins, Cephalosporins, Monobactams, Carbapenems, and Clavams. Medical Clinics of North America, 94(4), 805-820. doi:10.1016/j.mcna.2010.04.00

N′-[5-(4-Nitro­phen­yl)furan-2-yl­methyl­idene]-N,N-diphenyl­hydrazine

The title compound, C23H17N3O3, has an E configuration with respect to the C=N bond. The dihedral angle between the two phenyl rings bonded to the hydrazine group is 86.45 (13)°. The furan ring makes dihedral angles of 3.4 (2) and 7.06 (13)°, respectively, with the methyl­idenehydrazine C=N—N plane and the benzene ring

Light-responsive bent-core liquid crystals as candidates for energy conversion and storage

IDC would like to thank the Universitat Politècnica de València (UPV), for the FPI grant (PAID-2019-SP20190013), the Generalitat Valenciana (GVA) and the European Social Fund (ESF), for the FPI grant (ACIF/2020/233) and the mobility grant (CIBEFP/2021/53). NFKA would like to thank Universiti Teknologi MARA (UiTM) for sponsoring her academic sabbatical leave and allowing her to work on this project. AMF would like to thank the Carnegie Trust for the Universities of Scotland, for the Research Incentive Grant RIG008586, the Royal Society and Specac Ltd., for the Research Grant RGS\R1\201397, the Royal Society of Chemistry for the award of a mobility grant (M19- 0000), and the Scottish Government and the Royal Society of Edinburgh for the award of a SAPHIRE project. The authors from INMA greatly appreciate financial support from projects of the Spanish Government PGC2018-093761-B-C31 [MCIU/AEI/FEDER, UE] and the Gobierno de Aragón/FEDER (research group E47_20R). Thanks are given to the nuclear magnetic resonance, mass spectrometry, and thermal analysis services of the INMA (Univ. Zaragoza-CSIC)Peer reviewedPostprin

Bent-core liquid crystals joining the ethylene-oxide / lithium ion tandem : Ionic conductivity and dielectric response towards new electrolytes for energy applications

AMF would like to thank Ivan Dominguez-Candela for his support during the ferroelectric measurements.Peer reviewedPublisher PD