Riesgos y soluciones de seguridad existentes en el Internet de las cosas (IoT) en relación con Big Data

El avance tecnológico de la nueva era ha dado pie a la interconexión de dispositivos, aplicaciones, personas y datos, dando paso a la generación del Internet de las Cosas (IoT). Los múltiples datos recolectados son tan voluminosos y variables que deben ser almacenados en arquitecturas Big Data. Esta evolución ha brindado la oportunidad de tener mejor acceso, calidad y análisis de la información, pero a su vez existe un desafío para prevenir y mitigar los riesgos de seguridad asociados a la relación entre IoT y Big Data, poniendo en peligro la información recolectada y los datos sensibles del usuario, entre otros. El propósito del presente documento es realizar una revisión de literatura con el fin de recolectar los riesgos de seguridad encontrados entre la relación de Big Data e IoT, así mismo evaluar las soluciones actuales implementadas y concluir si éstas últimas cubren la necesidad de prevención y mitigación del riesgo

Photoactive bile salts with critical micellar concentration in the micromolar range

The aggregation behavior of bile salts is strongly dependent on the number of hydroxyl groups. Thus, cholic acid (CA), with three hydroxyls, starts forming aggregates at 15 mM, while deoxycholic, chenodeoxycholic or ursodeoxycholic acids, with two hydroxyls, start aggregating at 5-10 mM; for lithocholic acid, with only one hydroxyl group, aggregation is observed at lower concentration (2-3 mM). Here, the singular self-assembling properties of dansyl and naproxen derivatives of CA (3 beta-Dns-CA and 3 beta-NPX-CA, respectively) have been demonstrated on the basis of their photoactive properties. Thus, the emission spectra of 3 beta-Dns-CA registered at increasing concentrations (25-140 mu M) showed a remarkable non-linear enhancement in the emission intensity accompanied by a hypsochromic shift of the maximum and up to a three-fold increase in the singlet lifetime. The inflection point at around 50-70 mu M pointed to the formation of unprecedented assemblies at such low concentrations. In the case of 3 beta-NPX-CA, when the NPX relative triplet lifetime was plotted against concentration, a marked increase (up to two-fold) was observed at 40-70 mu M, indicating the formation of new 3 beta-NPX-CA assemblies at ca. 50 mu M. Additional evidence supporting the formation of new 3 beta-Dns-CA or 3 beta-NPX-CA assemblies at 40-70 mu M was obtained from singlet excited state quenching experiments using iodide. Moreover, to address the potential formation of hybrid assemblies, 1 : 1 mixtures of 3 beta-Dns-CA and 3 beta-NPX-CA (2-60 mu M, total concentration) were subjected to steady-state fluorescence experiments, and their behavior was compared to that of the pure photoactive derivatives. A lower increase in the emission was observed for 3 beta-NPX-CA in the mixture, while a huge increase was experienced by 3 beta-Dns-CA in the same concentration range (up to 60 mu M total). A partial intermolecular energy transfer from NPX to Dns, consistent with their reported singlet energies, was revealed, pointing to the formation of extremely fluorescent hybrid assemblies at 5-10 mu M (total concentration). The morphology of the entities was investigated by means of confocal microscopy. At 90 mu M, 3 beta-Dns-CA showed disperse assemblies in the mu m range.Financial support from the Spanish Government (Grants SEV-2012-0267 and CTQ2012-38754-C03-03) and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Gómez Mendoza, M.; Marín García, ML.; Miranda Alonso, MÁ. (2016). Photoactive bile salts with critical micellar concentration in the micromolar range. Physical Chemistry Chemical Physics. 18(18):12976-12982. https://doi.org/10.1039/c6cp00813eS1297612982181

Two-channel dansyl/tryptophan emitters with a cholic acid bridge as reporters for local hydrophobicity within supramolecular systems based on bile salts

The aim of the present work is to develop two-channel emitters to probe local hydrophobicity by means of fluorescence quenching within different biomimetic supramolecular environments. To achieve this goal, the dansyl (Dns) and tryptophan (Trp) fluorophores have been covalently attached to cholic acid (CA) in order to ensure simultaneous incorporation of the two emitting units into the same compartment. In principle, the two fluorophores of the synthesized Dns-CA-Trp probes could either exhibit an orthogonal behavior or display excited state interactions. The fluorescence spectra of 3 beta-Dns-CA-Trp showed a residual Trp emission band at ca. 350 nm and an enhanced Dns maximum in the 500-550 nm region. This reveals a partial intramolecular energy transfer, which is consistent with the Dns and Trp singlet energies. Thus, the two photoactive units are not orthogonal; nevertheless, 3 beta-Dns-CA-Trp seems appropriate as a two-channel reporter for the supramolecular systems of interest. Fluorescence quenching of 3 beta-Dns-CA-Trp by iodide (which remains essentially in bulk water) was examined within sodium cholate, sodium taurocholate, sodium deoxycholate and mixed micelles. Interestingly, a decrease in the emission intensity of the two bands was observed with increasing iodide concentrations. The most remarkable effect was observed for mixed micelles, where the quenching rate constants were one order of magnitude lower than in solution. As anticipated, the quenching efficiency by iodide decreased with increasing hydrophobicity of the microenvironment, a trend that can be correlated with the relative accessibility of the probe to the ionic quencher.Financial support from the Spanish Government (CTQ2012-38754-C03-03), Predoctoral FPU fellowship (AP2008-03295), and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Gómez Mendoza, M.; Marín García, ML.; Miranda Alonso, MÁ. (2014). Two-channel dansyl/tryptophan emitters with a cholic acid bridge as reporters for local hydrophobicity within supramolecular systems based on bile salts. Organic and Biomolecular Chemistry. 12(42):8499-8504. https://doi.org/10.1039/c4ob01394hS849985041242Vayá, I., Lhiaubet-Vallet, V., Jiménez, M. C., & Miranda, M. A. (2014). Photoactive assemblies of organic compounds and biomolecules: drug–protein supramolecular systems. Chem. Soc. Rev., 43(12), 4102-4122. doi:10.1039/c3cs60413fGomez-Mendoza, M., Marin, M. L., & Miranda, M. A. (2011). Dansyl Derivatives of Cholic Acid as Tools to Build Speciation Diagrams for Sodium Cholate Aggregation. The Journal of Physical Chemistry Letters, 2(7), 782-785. doi:10.1021/jz200178rGomez-Mendoza, M., Marin, M. L., & Miranda, M. A. (2012). Dansyl-Labeled Cholic Acid as a Tool To Build Speciation Diagrams for the Aggregation of Bile Acids. The Journal of Physical Chemistry B, 116(51), 14776-14780. doi:10.1021/jp308624hWaissbluth, O. L., Morales, M. C., & Bohne, C. (2006). Influence of Planarity and Size on Guest Binding with Sodium Cholate Aggregates. Photochemistry and Photobiology, 82(4), 1030. doi:10.1562/2006-02-14-ra-803Rinco, O., Kleinman, M. H., & Bohne, C. (2001). Reactivity of Benzophones in the Different Binding Sites of Sodium Cholate Aggregates. Langmuir, 17(19), 5781-5790. doi:10.1021/la010526cHofmann, A. F. (1999). The Continuing Importance of Bile Acids in Liver and Intestinal Disease. Archives of Internal Medicine, 159(22), 2647. doi:10.1001/archinte.159.22.2647Nuin, E., Gómez-Mendoza, M., Andreu, I., Marin, M. L., & Miranda, M. A. (2012). New Photoactive Compounds To Probe Cholic Acid and Cholesterol inside Mixed Micelles. Organic Letters, 15(2), 298-301. doi:10.1021/ol303201yHammad, M. ., & Müller, B. . (1998). Increasing drug solubility by means of bile salt–phosphatidylcholine-based mixed micelles. European Journal of Pharmaceutics and Biopharmaceutics, 46(3), 361-367. doi:10.1016/s0939-6411(98)00037-xHammad, M. ., & Müller, B. . (1998). Solubility and stability of tetrazepam in mixed micelles. European Journal of Pharmaceutical Sciences, 7(1), 49-55. doi:10.1016/s0928-0987(98)00006-2Hammad, M. (1998). Solubility and stability of clonazepam in mixed micelles. International Journal of Pharmaceutics, 169(1), 55-64. doi:10.1016/s0378-5173(98)00117-3Hendradi, E., Obata, Y., Isowa, K., Nagai, T., & Takayama, K. (2003). Effect of Mixed Micelle Formulations Including Terpenes on the Transdermal Delivery of Diclofenac. Biological & Pharmaceutical Bulletin, 26(12), 1739-1743. doi:10.1248/bpb.26.1739Parsaee, S., Sarbolouki, M. N., & Parnianpour, M. (2002). In-vitro release of diclofenac diethylammonium from lipid-based formulations. International Journal of Pharmaceutics, 241(1), 185-190. doi:10.1016/s0378-5173(02)00238-7Yu, J., Zhu, Y., Wang, L., Peng, M., Tong, S., Cao, X., … Xu, X. (2010). Enhancement of oral bioavailability of the poorly water-soluble drug silybin by sodium cholate/phospholipid-mixed micelles. Acta Pharmacologica Sinica, 31(6), 759-764. doi:10.1038/aps.2010.55Sznitowska, M., Klunder, M., & Placzek, M. (2008). Paclitaxel Solubility in Aqueous Dispersions and Mixed Micellar Solutions of Lecithin. CHEMICAL & PHARMACEUTICAL BULLETIN, 56(1), 70-74. doi:10.1248/cpb.56.70Nuin, E., Gomez-Mendoza, M., Marin, M. L., Andreu, I., & Miranda, M. A. (2013). Influence of Drug Encapsulation within Mixed Micelles on the Excited State Dynamics and Accessibility to Ionic Quenchers. The Journal of Physical Chemistry B, 117(32), 9327-9332. doi:10.1021/jp404353uCuquerella, M. C., Rohacova, J., Marin, M. L., & Miranda, M. A. (2010). Stereodifferentiation in fluorescence quenching within cholic acid aggregates. Chemical Communications, 46(27), 4965. doi:10.1039/c0cc00176gWu, J., Liu, W., Ge, J., Zhang, H., & Wang, P. (2011). New sensing mechanisms for design of fluorescent chemosensors emerging in recent years. Chemical Society Reviews, 40(7), 3483. doi:10.1039/c0cs00224kBronshtein, I., Afri, M., Weitman, H., Frimer, A. A., Smith, K. M., & Ehrenberg, B. (2004). Porphyrin Depth in Lipid Bilayers as Determined by Iodide and Parallax Fluorescence Quenching Methods and Its Effect on Photosensitizing Efficiency. Biophysical Journal, 87(2), 1155-1164. doi:10.1529/biophysj.104.041434Rohacova, J., Marin, M. L., Martínez-Romero, A., O’Connor, J.-E., Gomez-Lechon, M. J., Donato, M. T., … Miranda, M. A. (2009). Synthesis of new, UV-photoactive dansyl derivatives for flow cytometric studies on bile acid uptake. Organic & Biomolecular Chemistry, 7(23), 4973. doi:10.1039/b912134jFőrster, T. (1959). 10th Spiers Memorial Lecture. Transfer mechanisms of electronic excitation. Discuss. Faraday Soc., 27(0), 7-17. doi:10.1039/df9592700007Eaton, D. F. (1988). Reference materials for fluorescence measurement. 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Generation of the Thymine Triplet State by Through-Bond Energy Transfer

This is the peer reviewed version of the following article: Chem. Eur. J. 2019, 25, 7004 7011, which has been published in final form at https://doi.org/10.1002/chem.201900830. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Benzophenone (BP) and drugs containing the BP chromophore, such as the non-steroidal anti-inflammatory drug ketoprofen, have been widely reported as DNA photo-sensitizers through triplet-triplet energy transfer (TTET). In the present work, a direct spectroscopic fingerprint for the formation of the thymine triplet ((3)Thy*) by through-bond (TB) TTET from (BP)-B-3* has been uncovered. This has been achieved in two new systems that have been designed and synthesized with one BP and one thymine (Thy) covalently linked to the two ends of the rigid skeleton of the natural bile acids cholic and lithocholic acid. The results shown here prove that it is possible to achieve triplet energy transfer to a Thy unit even when the photosensitizer is at a long (non-bonding) distance.Financial support from the Spanish Government (Grant SEV-2016-0683 and Projects CTQ2012-38754-C03-03 and CTQ2015-70164P), the Generalitat Valenciana (Prometeo Program), and the Universitat Politecnica de Valencia (pre-doctoral FPI fellowship for P.M.) is gratefully acknowledged.Miró, P.; Gomez-Mendoza, M.; Sastre Navarro, GI.; Cuquerella Alabort, MC.; Miranda Alonso, MÁ.; Marín García, ML. (2019). Generation of the Thymine Triplet State by Through-Bond Energy Transfer. Chemistry - A European Journal. 25(28):7004-7011. https://doi.org/10.1002/chem.201900830S700470112528Mouret, S., Baudouin, C., Charveron, M., Favier, A., Cadet, J., & Douki, T. (2006). Cyclobutane pyrimidine dimers are predominant DNA lesions in whole human skin exposed to UVA radiation. 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Mutagenicity of a unique thymine-thymine dimer or thymine-thymine pyrimidine pyrimidone (6-4) photoproduct in mammalian cells. Nucleic Acids Research, 24(10), 1837-1840. doi:10.1093/nar/24.10.1837Görner, H. (1990). Phosphorescence of nucleic acids and DNA components at 77 K. Journal of Photochemistry and Photobiology B: Biology, 5(3-4), 359-377. doi:10.1016/1011-1344(90)85051-wLamola, A. A., & Eisinger, J. (1971). Excited states of nucleotides in water at room temperature. Biochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 240(3), 313-325. doi:10.1016/0005-2787(71)90524-7Cuquerella, M. C., Lhiaubet-Vallet, V., Bosca, F., & Miranda, M. A. (2011). Photosensitised pyrimidine dimerisation in DNA. Chemical Science, 2(7), 1219. doi:10.1039/c1sc00088hBlancafort, L., & Voityuk, A. A. (2018). Thermally induced hopping model for long-range triplet excitation energy transfer in DNA. Physical Chemistry Chemical Physics, 20(7), 4997-5000. doi:10.1039/c7cp07811kAntusch, L., Gaß, N., & Wagenknecht, H.-A. (2016). Elucidation of the Dexter-Type Energy Transfer in DNA by Thymine-Thymine Dimer Formation Using Photosensitizers as Artificial Nucleosides. Angewandte Chemie International Edition, 56(5), 1385-1389. doi:10.1002/anie.201610065Antusch, L., Gaß, N., & Wagenknecht, H.-A. (2016). Aufklärung des Dexter-Energietransfers in DNA an der Thymin-Thymin-Dimerbildung mithilfe von Photosensibilisatoren als artifizielle Nucleoside. Angewandte Chemie, 129(5), 1406-1410. doi:10.1002/ange.201610065Kanvah, S., Joseph, J., Schuster, G. B., Barnett, R. N., Cleveland, C. L., & Landman, U. (2010). Oxidation of DNA: Damage to Nucleobases. Accounts of Chemical Research, 43(2), 280-287. doi:10.1021/ar900175aGiese, B., Amaudrut, J., Köhler, A.-K., Spormann, M., & Wessely, S. (2001). Direct observation of hole transfer through DNA by hopping between adenine bases and by tunnelling. Nature, 412(6844), 318-320. doi:10.1038/35085542Giese, B. (2000). Long-Distance Charge Transport in DNA:  The Hopping Mechanism. Accounts of Chemical Research, 33(9), 631-636. doi:10.1021/ar990040bTakada, T., Kawai, K., Fujitsuka, M., & Majima, T. (2004). Direct observation of hole transfer through double-helical DNA over 100 A. Proceedings of the National Academy of Sciences, 101(39), 14002-14006. doi:10.1073/pnas.0402756101Takada, T., Kawai, K., Cai, X., Sugimoto, A., Fujitsuka, M., & Majima, T. (2004). Charge Separation in DNA via Consecutive Adenine Hopping. Journal of the American Chemical Society, 126(4), 1125-1129. doi:10.1021/ja035730wTakada, T., Fujitsuka, M., & Majima, T. (2007). Single-molecule observation of DNA charge transfer. Proceedings of the National Academy of Sciences, 104(27), 11179-11183. doi:10.1073/pnas.0700795104Kawai, K., & Majima, T. (2013). Hole Transfer Kinetics of DNA. 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J., Fujitsuka, M., Kawai, K., & Majima, T. (2011). Direct Measurement of the Dynamics of Excess Electron Transfer through Consecutive Thymine Sequence in DNA. Journal of the American Chemical Society, 133(39), 15320-15323. doi:10.1021/ja2068017Lin, S.-H., Fujitsuka, M., & Majima, T. (2016). Excess-Electron Transfer in DNA by a Fluctuation-Assisted Hopping Mechanism. The Journal of Physical Chemistry B, 120(4), 660-666. doi:10.1021/acs.jpcb.5b10857Manetto, A., Breeger, S., Chatgilialoglu, C., & Carell, T. (2006). Complex Sequence Dependence by Excess-Electron Transfer through DNA with Different Strength Electron Acceptors. Angewandte Chemie International Edition, 45(2), 318-321. doi:10.1002/anie.200502551Manetto, A., Breeger, S., Chatgilialoglu, C., & Carell, T. (2006). Komplexe Sequenzabhängigkeit beim Transport von Überschusselektronen durch DNA mit verschieden starken Acceptoren. Angewandte Chemie, 118(2), 325-328. doi:10.1002/ange.200502551Heil, K., Pearson, D., & Carell, T. (2011). Chemical investigation of light induced DNA bipyrimidine damage and repair. Chem. Soc. Rev., 40(8), 4271-4278. doi:10.1039/c000407nHaas, C., Kräling, K., Cichon, M., Rahe, N., & Carell, T. (2004). Excess Electron Transfer Driven DNA Does Not Depend on the Transfer Direction. Angewandte Chemie International Edition, 43(14), 1842-1844. doi:10.1002/anie.200353067Haas, C., Kräling, K., Cichon, M., Rahe, N., & Carell, T. (2004). Excess Electron Transfer Driven DNA Does Not Depend on the Transfer Direction. Angewandte Chemie, 116(14), 1878-1880. doi:10.1002/ange.200353067Carell, T. (1995). Sunlight-Damaged DNA Repaired with Sunlight. Angewandte Chemie International Edition in English, 34(22), 2491-2494. doi:10.1002/anie.199524911Carell, T. (1995). Reparatur von sonnenlichtgeschädigter DNA mit Sonnenlicht. Angewandte Chemie, 107(22), 2697-2700. doi:10.1002/ange.19951072207Breeger, S., Hennecke, U., & Carell, T. (2004). Excess Electron-Transfer-Based Repair of a Cis-Syn Thymine Dimer in DNA Is Not Sequence Dependent. Journal of the American Chemical Society, 126(5), 1302-1303. doi:10.1021/ja038358tCuquerella, M. C., Lhiaubet-Vallet, V., Cadet, J., & Miranda, M. A. (2012). Benzophenone Photosensitized DNA Damage. Accounts of Chemical Research, 45(9), 1558-1570. doi:10.1021/ar300054eDelatour, T., Douki, T., D’Ham, C., & Cadet, J. (1998). Photosensitization of thymine nucleobase by benzophenone through energy transfer, hydrogen abstraction and one-electron oxidation. Journal of Photochemistry and Photobiology B: Biology, 44(3), 191-198. doi:10.1016/s1011-1344(98)00142-0Schreier, W. J., Schrader, T. E., Koller, F. O., Gilch, P., Crespo-Hernandez, C. E., Swaminathan, V. N., … Kohler, B. (2007). Thymine Dimerization in DNA Is an Ultrafast Photoreaction. Science, 315(5812), 625-629. doi:10.1126/science.1135428Schreier, W. J., Kubon, J., Regner, N., Haiser, K., Schrader, T. E., Zinth, W., … Gilch, P. (2009). Thymine Dimerization in DNA Model Systems: Cyclobutane Photolesion Is Predominantly Formed via the Singlet Channel. Journal of the American Chemical Society, 131(14), 5038-5039. doi:10.1021/ja900436tSandros, K., Haglid, F., Ryhage, R., Ryhage, R., & Stevens, R. (1964). Transfer of Triplet State Energy in Fluid Solutions. III. Reversible Energy Transfer. Acta Chemica Scandinavica, 18, 2355-2374. doi:10.3891/acta.chem.scand.18-2355Douki, T., Bérard, I., Wack, A., & Andrä, S. (2014). Contribution of Cytosine-Containing Cyclobutane Dimers to DNA Damage Produced by Photosensitized Triplet-Triplet Energy Transfer. Chemistry - A European Journal, 20(19), 5787-5794. doi:10.1002/chem.201303905Gut, I. G., Wood, P. D., & Redmond, R. W. (1996). Interaction of Triplet Photosensitizers with Nucleotides and DNA in Aqueous Solution at Room Temperature. Journal of the American Chemical Society, 118(10), 2366-2373. doi:10.1021/ja9519344Miro, P., Lhiaubet-Vallet, V., Marin, M. L., & Miranda, M. A. 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"Snorkelling" vs. "diving" in mixed micelles probed by means of a molecular bathymeter

[EN] A photoactive bathymeter based on a carboxylic acid moiety covalently linked to a signalling methoxynaphthalene (MNP) fluorophore has been designed to prove the concept of "snorkelling" vs. "diving" in mixed micelles (MM). The carboxylic acid "floats" on the MM surface, while the MNP unit sinks deep in MM. The rate constants of MNP fluorescence quenching by iodide, which remains basically in water, consistently decrease with increasing spacer length, revealing different regions. This is associated with the distance MNP should "dive" in MM to achieve protection from aqueous reactants. Unequivocal proof of the exergonic photoinduced electron transfer was obtained from the UV-visible spectral signature of I-3(-) upon steady-state photolysis. The applicability of the bathymeter was examined upon testing a family of MNP derivatives. The obtained results were validated by comparison with different lipophilicity tests: (i) a modified version of the K-ow partition coefficient and (ii) the retention factor on thin layer chromatography. This concept could potentially be extended to test drugs or pharmacophores exhibiting any photoactive moiety.Financial support from the Spanish Government (SEV-2016-0683), Red RETICS de Investigacion de Reacciones Adversas a Alergenos y Farmacos (RIRAAF), Instituto de Salud Carlos III (RD012/0013, RD16/0006/0030, FIS PI16/01877), VLC-Campus and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Rodríguez Muñiz, GM.; Gomez Mendoza, M.; Nuin Pla, NE.; Andreu Ros, MI.; Marín García, ML.; Miranda Alonso, MÁ. (2017). "Snorkelling" vs. "diving" in mixed micelles probed by means of a molecular bathymeter. Organic & Biomolecular Chemistry. 15(48):10281-10288. https://doi.org/10.1039/c7ob02595eS10281102881548Porter, C. J. H., Trevaskis, N. L., & Charman, W. N. (2007). 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Isonitriles as Alkyl Radical Precursors in Visible Light Mediated Hydro- and Deuterodeamination Reactions

Herein, we report the use of isonitriles as alkyl radical precursors in light-mediated hydro- and deuterodeamination reactions. The reaction is scalable, shows broad functional group compatibility and potential to be used in late-stage functionalization. Importantly, the method is general for Cα-primary, Cα-secondary and Cαtertiary alkyl isonitriles. For most examples, high yields were obtained through direct visible-light irradiation of the isonitrile in the presence of a silyl radical precursor. Interestingly, in the presence of an organic photocatalyst (4CzIPN) a dramatic acceleration was observed. Indepth mechanistic studies using UV/Vis absorption, steady-state and time-resolved photoluminescence, and transient absorption spectroscopy suggest that the excited state of 4CzIPN can engage in a single-electron transfer with the isonitrileWe thank the European Research Council (ERC CoG 101002715 SCAN) and Spanish MCIN/AEI/10.13039/ 501100011033 (grant n° PID2019-107380GB-I00 and PID2022-142594NB-I00 to MT, PID2022-141688OB-I00 and PID2020-118593RB-C22 to ML, PID2019-106184GB-I00, PID2022-139318NB I00 and RED2022-134287-T to IF) for financial support. I.Q. and L.N. thank Comunidad de Madrid for a predoctoral fellowship, and M.M. acknowledges Ministerio de Universidades for a FPU fellowship (FPU20/06

Towards the improvement of methane production in CO2 photoreduction using Bi2WO6/TiO2 heterostructures

Russelite bismuth tungstate (Bi2WO6) has been widely reported for the photocatalytic degradation and mineralization of a myriad of pollutants as well as organic compounds. These materials present perovskite-like structure with hierarchical morphologies, which confers excellent optoelectronic properties as potentials candidates for photocatalytic solar fuels production. Here, we propose the development of Bi2WO6/TiO2 heterojunctions for CO2 photoreduction, as a promising solution to produce fuels, alleviate global warming and tackle fossil fuel shortage. Our results show an improvement of the photocatalytic activity of the heterojunctions compared to the pristine semiconductors. Near Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) experiments reveals a preferential CO2 adsorption over TiO2. On the other hand, transient absorption spectroscopy measurements show that the charge transfer pathway in Bi2WO6/TiO2 hybrids leads to longer-lived photogenerated carriers in spatially separated redox active sites, which favor the reduction of CO2 into highly electron demanding fuels and chemicals, such as CH4 and C2H6Financial support has been received from the European Research Council (ERC), through HYMAP project (grant agreement No. 648319), under the European Union's Horizon 2020 research and innovation program, as well as from the Marie Sklodowska-Curie grant agreement No. 754382. L.C. acknowledges funding from the project ARMONIA (PID2020–119125RJ-I00) funded by MCIN/AEI/10.13039/ 501100011033. Financial support has also been received from AEIMINECO/FEDER (Nympha Project, PID2019–106315RB-I00), "Comunidad de Madrid" regional government, and the European Structural Funds (FotoArt-CM project, S2018/NMT-4367). Authors also acknowledge financial support from the grant PLEC2021–007906 funded by MCIN/AEI/10.13039/501100011033 and the "European Union NextGenerationEU/PRTR"

Controlled Synthesis of Up-Conversion NaYF4:Yb,Tm Nanoparticles for Drug Release under Near IR-Light Therapy

Up-Conversion materials have received great attention in drug delivery applications in recent years. A specifically emerging field includes the development of strategies focusing on photon processes that promote the development of novel platforms for the efficient transport and the controlled release of drug molecules in the harsh microenvironment. Here, modified reaction time, thermal treatment, and pH conditions were controlled in the synthesis of NaYF(4):Yb,Tm up-converted (UC) material to improve its photoluminescence properties. The best blue-emission performance was achieved for the UC3 sample prepared through 24 h-synthesis without thermal treatment at a pH of 5, which promotes the presence of the β-phase and smaller particle size. NaYF(4):Yb,Tm has resulted in a highly efficient blue emitter material for light-driven drug release under near-IR wavelength. Thus, NaYF(4):Yb,Tm up-converted material promotes the N-O bond cleavage of the oxime ester of Ciprofloxacin (prodrug) as a highly efficient photosensitized drug delivery process. HPLC chromatography and transient absorption spectroscopy measurements were performed to evaluate the drug release conversion rate. UC3 has resulted in a very stable and easily recovered material that can be used in several reaction cycles. This straightforward methodology can be extended to other drugs containing photoactive chromophores and is present as an alternative for drug release systems

Iterative dual-metal and energy transfer catalysis enables stereodivergence in alkyne difunctionalization: Carboboration as case study

Stereochemically defined tetrasubstituted olefins are widespread structural elements of organic molecules and key intermediates in organic synthesis. However, flexible methods enabling stereodivergent access to E and Z isomers of fully substituted alkenes from a common precursor represent a significant challenge and are actively sought after in catalysis, especially those amenable to complex multifunctional molecules. Herein, we demonstrate that iterative dual-metal and energy transfer catalysis constitutes a unique platform for achieving stereodivergence in the difunctionalization of internal alkynes. The utility of this approach is showcased by the stereodivergent synthesis of both stereoisomers of tetrasubstituted β-boryl acrylates from internal alkynoates with excellent stereocontrol via sequential carboboration and photoisomerization. The reluctance of electron-deficient internal alkynes to undergo catalytic carboboration has been overcome through cooperative Cu/Pd-catalysis, whereas an Ir complex was identified as a versatile sensitizer that is able to photoisomerize the resulting sterically crowded alkenes. Mechanistic studies by means of quantum-chemical calculations, quenching experiments, and transient absorption spectroscopy have been applied to unveil the mechanism of both stepsPGC2018-098660−B-I00, Horizon2020 (ERC) No.648319, PID2019-106315RB-I00, PID2020-118593RB-C22