The metal-organic framework MFU-4 shows preferential adsorption of CO2 over N-2. This cannot be explained in terms of pore size only. Computational modelling suggests that the unique structure and flexibility of its small 8Cl-cube pore shows a unique gate-diffusion behaviour with different responses to CO2 and N-2. ; G. S. thanks the Spanish government for the provision of Severo Ochoa project (SEV 2012-0267) and SGAI-CSIC for computing time. Financial support by the DFG (Priority Program SPP 1362 "Porous Metal-organic Frameworks") is gratefully acknowledged (D. V. and D. D.). ; Sastre Navarro, GI.; Van Den Bergh, J.; Kapteijn, F.; Denysenko, D.; Volkmer, D. (2014). Unveiling the mechanism of selective gate-driven diffusion of CO2 over N2 in MFU-4 metal-organic framework. Dalton Transactions. 43(25):9612-9619. https://doi.org/10.1039/c4dt00365a ; S ; 9612 ; 9619 ; 43 ; 25
The database of prospective zeolites (www. hypotheticalzeolites.net) has been screened in search of feasible zeolites. Previous criteria of zeolite feasibil- ity have been reviewed, based on descriptors such as energy, density, average and distribution of ring sizes, and more importantly that of Li et al. (LID criteria) presented recently [Angew. Chem. Int. Ed. 2013, 52, 1673], based on Si O, O . O, and Si . Si distances of SLC-minimised struc- tures. In spite of the still large number of feasible zeolites according to this and other criteria, a number of research- ers wonder why there are so many feasible and so few synthesised zeolites. Without answering this difficult question, a new criteria is proposed in this study based on the fact that T . T . T angles (T is tetrahedral atom) show spe- cific ranges of values depending on the ring size to which they belong. Based on improved definitions to count and enumerate rings in zeolites, and with data from the IZA database, we introduce the TTT criteria, which we propose to use after the LID criteria, to further narrow the space of feasible zeolites. ; We thank ASIC computational centre of UPV for making available their computational resources. UPV is acknolwdeged by funding through project PAID-05-12. G. S. thanks the Spanish government for the provision of Severo Ochoa project (SEV 2012-0267) and MAT2012-31657 project. Professors Mike Treacy and Christian Baerlocher are gratefully acknowledged for useful discussions. Laurent Baumes is thanked by initial training with the database. ; Liu, X.; Valero Cubas, S.; Argente Villaplana, E.; Botti Navarro, VJ.; Sastre Navarro, GI. (2015). The importance of T . T . T angles in the feasibility of zeolites. Zeitschrift fur Kristallographie. Crystalline materials. 230(5):291-299. https://doi.org/10.1515/zkri-2014-1801 ; S ; 291 ; 299 ; 230 ; 5
[EN] ITQ-39, a multipore zeolite with interconnected 12- and 10-ring channel systems, effectively catalyzes the alkylation of two low value naphtha fractions for the production of diesel range alkylaromatics. A catalytic and molecular dynamics study allows us to conclude that its higher selectivity to the desired diesel fraction and, especially, its longer catalyst life as compared to beta or MCM-22, conventionally used as heterogeneous alkylation catalysts, are due to the combined contribution of its small nano-sized crystallites, moderate Bronsted acidity and unique framework topology. The small diffusion coefficients obtained for alkylaromatics on ITQ-39 as compared to those corresponding to the large pore beta zeolite evidence the significant diffusional problems of most of the reactants and products through the channels of the ITQ-39 structure. Thus, alkylation reactions on this zeolite seem to occur mainly on the most external acid sites (external surface, pore mouths), whereas the zeolite structure contributes positively by preventing undesired reactions to occur, which would result in lower selectivity to the monoalkylated products and in a faster catalyst deactivation. ; Financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160 and MAT2012-31657, by the European Union through ERC-AdG-2014-671093 - SynCatMatch and by the Generalitat Valenciana through the Prometeo program (PROME-TEOII/2013/011) is acknowledged. Repsol is thanked for financial support and permission to publish these results. G.S. thanks ASIC-UPV for computing time. The Electron Microscopy Service of the UPV is acknowledged for their help in samples characterization. ; Martínez Armero, ME.; Moliner Marin, M.; Sastre Navarro, GI.; Rey Garcia, F.; Martínez, C.; Corma Canós, A. (2016). ITQ-39 zeolite, an efficient catalyst for the conversion of low value naphtha fractions into diesel fuel: The role of pore size on molecular diffusion and reactivity. Journal of ...
The combination of different experimental techniques, such as solid C-13 and H-1 magic-angle spinning NMR spectroscopy, fluorescence spectroscopy and powder X-ray diffraction, together with theoretical calculations allows the determination of the unique structure directing the role of the bulky aromatic proton sponge 1,8-bis(dimethylamino)naphthalene (DMAN) towards the extra-large-pore ITQ-51 zeolite through supra-molecular assemblies of those organic molecules. ; This work has been supported by the Spanish Government through Consolider Ingenio 2010-Multicat, the 'Severo Ochoa Programme' (SEV 2012-0267), MAT2012-37160; UPV through PAID-06-11 (no. 1952); the Swedish Research Council (VR) and the Swedish Governmental Agency for Innovation Systems (VINNOVA). ; Martínez Franco, R.; Sun, J.; Sastre Navarro, GI.; Yun, Y.; Zou, X.; Moliner Marin, M.; Corma Canós, A. (2014). Supra-molecular assembly of aromatic proton sponges to direct the crystallization of extra-large-pore zeotypes. Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences. 470:1-13. https://doi.org/10.1098/rspa.2014.0107 ; S ; 1 ; 13 ; 470 ; Moliner, M., Rey, F., & Corma, A. (2013). Towards the Rational Design of Efficient Organic Structure-Directing Agents for Zeolite Synthesis. Angewandte Chemie International Edition, 52(52), 13880-13889. doi:10.1002/anie.201304713 ; Freyhardt, C. C., Tsapatsis, M., Lobo, R. F., Balkus, K. J., & Davis, M. E. (1996). A high-silica zeolite with a 14-tetrahedral-atom pore opening. Nature, 381(6580), 295-298. doi:10.1038/381295a0 ; Wagner, P., Yoshikawa, M., Tsuji, K., Davis, M. E., Wagner, P., Lovallo, M., & Taspatsis, M. (1997). CIT-5: a high-silica zeolite with 14-ring pores. Chemical Communications, (22), 2179-2180. doi:10.1039/a704774f ; Burton, A., Elomari, S., Chen, C.-Y., Medrud, R. C., Chan, I. Y., Bull, L. M., … Vittoratos, E. S. (2003). SSZ-53 and SSZ-59: Two Novel Extra-Large Pore Zeolites. Chemistry - A European Journal, 9(23), 5737-5748. ...
[EN] Colchicine (COL) is a bioactive molecule with antitumor properties. When COL binds to tubulin (TU), it inhibits microtubule assembly dynamics. We have investigated COL-TU interactions using laser flash photolysis (LFP) technique and performing fully flexible molecular dynamics simulations. Excitation of COL at 355 nm in aqueous medium did not lead to any transient absorption spectrum. By contrast, in the presence of TU a transient peaking at lambda(max) ca. 420 nm was registered and assigned as triplet excited COL complexed with TU ((COL)-C-3*@TU). In aerated medium, the lifetime was tau ca. 160 mu s and the quantum yield was 0.138. Likewise, when the bicyclic COL analog MTC was submitted to LFP in the presence of TU, (MTC)-M-3@TU* was detected with a lifetime of ca. 62 ms and a quantum yield of 0.296, Aqueous solutions of MTC did not produce any signal in the microsecond timescale. The triplet energy of MTC was obtained by means of emission measurements and found to be ca. 200 kJ mol(-1), a value that matches with that previously reported for COL (188 kJ mol(-1)). Molecular dynamic simulations, both with the ground and triplet excited state, reveal a strong interaction between COL and TU to give stabilized complexes with restricted mobility inside the protein binding site. These results demonstrate that LFP is a useful methodology to study the binding of COL derivatives to TU and open a new way to evaluate the interactions of non-fluorescent anticancer drugs with this protein. ; Financial support from the Spanish Government (grants CTQ2010-19909; BFU2011-23416 and SEV 2012-0267), the Generalitat Valenciana (Prometeo II/2013/005) and Comunidad de Madrid (S2010/BMD-2353) is gratefully acknowledged. G.S. thanks ASIC-UPV for computing time. ; Bosca Mayans, F.; Sastre Navarro, GI.; Andreu, JM.; Jornet, D.; Tormos Faus, RE.; Miranda Alonso, MÁ. (2015). Drug-tubulin interactions interrogated by transient absorption spectroscopy. RSC Advances. 5(61):49451-49458. https://doi.org/10.1039/C5RA05636E ; S ; 49451 ...
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.201900830 ; S ; 7004 ; 7011 ; 25 ; 28 ; Mouret, 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. Proceedings of the National Academy of Sciences, 103(37), 13765-13770. doi:10.1073/pnas.0604213103 ; Setlow, R. B., Grist, E., Thompson, K., & Woodhead, A. D. (1993). ...
he influence of non-covalent σ–π orbital interactions on triplet–triplet energy transfer (TTET) through tuning of the donor excitation energy remains basically unexplored. In the present work, we have investigated intermolecular TTET using donor moieties covalently linked to a rigid cholesterol (Ch) scaffold. For this purpose, diaryl ketones of π,π* electronic configuration tethered to α- or β-Ch were prepared from tiaprofenic acid (TPA) and suprofen (SUP). The obtained systems TPA-α-Ch, TPA-β-Ch, SUP-α-Ch and SUP-β-Ch were submitted to photophysical studies (laser flash photolysis and phosphorescence), in order to delineate the influence of steric shielding and σ–π orbital interactions on the rate of TTET to a series of energy acceptors. As a matter of fact, fine tuning of the donor triplet energy significantly modifies the rate constants of TTET in the absence of diffusion control. The experimental results are rationalized by means of theoretical calculations using first principles methods based on DFT as well as molecular dynamics. ; Financial support from the Generalitat Valenciana (Prometeo Program), the Spanish Government (CTQ2010-19909, SEV-2012-0267 and FPU fellowship for F.P.) and the Carlos III Institute of Health (Grant RIRAAF, RETICS program and Miguel Servet Contract CP11/00154 for I. A.) is gratefully acknowledged. We thank ASIC-UPV for computing time. Dedicated to Prof. Diego Cortes on the occasion of his 60th birthday. ; Andreu Ros, MI.; Morera Bertomeu, IM.; Palumbo, F.; Sastre Navarro, GI.; Bosca Mayans, F.; Miranda Alonso, MÁ. (2015). Steric-shielding vs sigma-pi orbital interactions in triplet-triplet energy transfer. Chemical Science. 6(7):4035-4041. https://doi.org/10.1039/c5sc00823a ; S ; 4035 ; 4041 ; 6 ; 7 ; Baldo, M. A., & Forrest, S. R. (2000). Transient analysis of organic electrophosphorescence: I. Transient analysis of triplet energy transfer. Physical Review B, 62(16), 10958-10966. doi:10.1103/physrevb.62.10958 ; Scaiano, J. C., Leigh, W., Meador, M. A., & Wagner, P. J. ...
[EN] Through-bond triplet exciplex formation in donor-acceptor systems linked through a rigid bile acid scaffold has been demonstrated on the basis of kinetic evidence upon population of the triplet acceptors (naphthalene, or biphenyl) by through-bond triplet-triplet energy transfer from benzophenone. ; Financial support from the Spanish Government (Grants SEV-2012-0267, CTQ2012-38754-C03-03, CTQ2013-47872-C2-1-P and JCI-2011-09926), EU (PCIG12GA-2012-334257), Generalitat Valenciana (Prometeo Program), and Technical University of Valencia (VLC/Campus, ASIC-UPV for computational facilities and Predoctoral FPI fellowship for P. Miro) is gratefully acknowledged. ; Miró Richart, P.; Vayá Pérez, I.; Sastre Navarro, GI.; Jiménez Molero, MC.; Marín García, ML.; Miranda Alonso, MÁ. (2016). Triplet energy management between two signaling units through cooperative rigid scaffolds. Chemical Communications. 52(4):713-716. https://doi.org/10.1039/c5cc08102e ; S ; 713 ; 716 ; 52 ; 4
[EN] Discrimination between different gases is an essential aspect for industrial and environmental applications involving sensing and separation. Several classes of porous materials have been used in this context, including zeolites and more recently MOFs. However, to reach high selectivities for the separation of gas mixtures is a challenging task that often requires the understanding of the specific interactions established between the porous framework and the gases. Here we propose an approach to obtain an enhanced selectivity based on the use of compartmentalized coordination polymers, named CCP-1 and CCP-2, which are crystalline materials comprising isolated discrete cavities. These compartmentalized materials are excellent candidates for the selective separation of CO2 from methane and nitrogen. A complete understanding of the sorption process is accomplished with the use of complementary experimental techniques including X-ray diffraction, adsorption studies, inelastic- and quasi-elastic neutron scattering, magnetic measurements and molecular dynamics calculations. ; Financial support from the Spanish MINECO (CTQ2014-59209-P, MAT2014-56143-R and MAT2015-71842-P), the Generalitat Valenciana (Prometeo and ISIC-Nano programs), the EU (ERC-2016-CoG 724681-S-CAGE) and the VLC/Campus Program is gratefully acknowledged. We thank the Spanish government for the provision of a Severo Ochoa project (SEV-2012-0267) and a Maria de Maeztu project (MDM-2015-0538). M. G.-M. thanks MICINN for a predoctoral FPU grant and the EU for a Marie Sklodowska-Curie postdoctoral fellowship (H2020-MSCA-IF-EF-658224). N. C. G. thanks the Generalitat Valenciana for a VALi+d predoctoral fellowship. J. A. R. -V. acknowledges CSIC for a JAE-doc contract. G. S. thanks SGAI-CSIC for computing time. G. M. E. acknowledges the Blaise Pascal International Chair for financial support and the Ramon y Cajal Programme. J. M. Martinez-Agudo and G. Agusti from the University of Valencia are gratefully acknowledged for magnetic measurements. We are ...