Suchergebnisse

[EN] Imines are ubiquitous intermediates in organic synthesis, and the metal-mediated imination of alcohols is one of the most direct and simple methods for their synthesis. However, reported protocols lack compatibility with many other functional groups since basic supports/media, pure oxygen atmospheres, and/or released hydrogen gas are required during reaction. Here we show that, in contrast to previous metal-catalyzed methods, hexa-aqueous Ru(III) catalyzes the imination of primary alcohols with very wide functional group tolerance, at slightly acid pH and under low oxygen atmospheres. The inorganic metal complex can be supported and stabilized, integrally, within either faujasite-type zeolites (Y and X) or a metal organic framework (MOF), to give a reusable heterogeneous catalyst which provides an industrially viable process well below the flammability limit of alcohols and amines. ; This work was supported by the MINECO (Spain) (Projects CTQ2017-86735-P, CTQ2016-75671-P, CTQ2014-56312-P, CTQ2014-55178-R, and MAT2013-40823-R and Excellence Units "Severo Ochoa" SEV2016-0683 and "Maria de Maeztu" and MDM-2015-0538) and the European Union through ERC-AdG-2014-671093 (SynCatMatch) and the Ministero dell'Istruzione, dell'Universita e della Ricerca (Italy) (FFABR 2017). M.M. thanks the MINECO for a predoctoral contract. RA. thanks UPV for a postdoctoral contract. J.F.-S. acknowledges financial support from the Subprograma Atraccio de Talent - Contractes Postdoctorals de la Universitat de Valencia. We also acknowledge SOLEIL for provision of the synchrotron radiation facility and thank Pierre Fertey for his assistance. ; Mon, M.; Adam-Ortiz, R.; Ferrando-Soria, J.; Corma Canós, A.; Pardo, E.; Armentano, D.; Leyva Perez, A. (2018). Stabilized Ru[(H2O)(6)](3+) in Confined Spaces (MOFs and Zeolites) Catalyzes the lmination of Primary Alcohols under Atmospheric Conditions with Wide Scope. ACS Catalysis. 8(11):10401-10406. https://doi.org/10.1021/acscatal.8b03228 ; S ; 10401 ; 10406 ; 8 ; 11

Purification of methane from other light hydrocarbons in natural gas is a topic of intense research due to its fundamental importance in the utilization of natural gas fields. Porous materials have emerged as excellent alternative platforms to conventional cryogenic methodologies to perform this task in a cost- and energy-efficient manner. Here we report a new family of isoreticular chiral MOFs, prepared from oxamidato ligands derived from natural amino acids L-alanine, L-valine and L-leucine, where, by increasing the length of the alkyl residue of the amino acid, the charge density of the MOF's channels can be tuned (1 > 2 > 3), decreasing the adsorption preference towards methane over light hydrocarbons thus improving this purification process. The validity of our rational design strategy has been proved by a combination of single-component adsorption isotherms, adsorption kinetics of CH4, C2H6, C3H8 and n-C4H10, and breakthrough experiments of binary CH4/C2H6 and CH4/C3H8 mixtures. ; This work was supported by the mineco (Spain) (Projects CTQ2013-46362-P, MAT2013-45008-P, MAT2016-81732-ERC, CTQ2016-75671-P and Excellence Unit "Maria de Maeztu" MDM-2015-0538), the Generalitat Valenciana (Spain) (Project PROMETEOII/2014/070, PROMETEOII/2014/004) and the Ministero dell'Istruzione, dell'Università e della Ricerca (Italy). T. G. and M. M. thank the Universitat de València and the mineco for predoctoral contracts. Thanks are also extended to the Ramón y Cajal Program (E. P. and E. V. R.-F. (RYC-2012-11427)). B. S. and J. G. acknowledge the financial support of the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 335746, CrystEng-MOF-MMM.

Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal-organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs@MOF) and its post-assembly metalation to give a PdII-AuIII supramolecular assembly, crystallography underpinned. These SCCs@MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis. ; This work was supported by the MINECO (Spain) (Projects CTQ2016-75671-P and 2017-86735-P, and Excellence Units "Severo Ochoa" and "Maria de Maeztu" SEV-2016-0683 and MDM-2015-0538), the Ministero dell'Istruzione, dell'Università e della Ricerca (Italy), and the Engineering and Physical Sciences Research Council (UK). M.M. thanks the MINECO for a predoctoral contract. R.A. thanks UPV and R.G. thanks ITQ for the corresponding contracts. D.A. thanks the "Fondo per il finanziamento delle attività base di ricerca". E.P. acknowledges financial support from the European Research Council under the European Union's Horizon 2020 research and innovation programme/ERC Grant Agreement No. 814804, MOF-reactors. Thanks are also extended to the "Subprograma Atracció de Talent-Contractes Post-doctorals de la Universitat de Valencia" and the "2018 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation" (J.F.-S.). We thank the Diamond Light Source for awarded beamtime (proposal number MT18768) and provision of synchrotron radiation facility, and Dr. David Allan and Dr. Sarah Barnett for their assistance at the I19 beamline.

Understanding/visualizing the established interactions between gases and adsorbents is mandatory to implement better performance materials in adsorption/separation processes. Here we report the unique behavior of a rare example of a hemilabile chiral three-dimensional metal–organic framework (MOF) with an unprecedented qtz-e-type topology, with formula CuII2(S,S)-hismox·5H2O (1) (hismox = bis[(S)-histidine]oxalyl diamide). 1 exhibits a continuous and reversible breathing behavior, based on the hemilability of carboxylate groups from l-histidine. In situ powder (PXRD) and single crystal X-ray diffraction (SCXRD) using synchrotron radiation allowed us to unveil the crystal structures of four different host–guest adsorbates (Ar@1, N2@1, CO2@1, and C3H6@1), rationalize the breathing motion, and unravel the mechanisms governing the adsorption of these gases. Then this information was transferred to implement efficient separations of mixtures of industrial and environmental relevance, CO2/N2, CO2/CH4, and C3H8/C3H6, using 1 in packed columns as the stationary phase and dispersed in a mixed matrix membrane. ; This work was supported by the MINECO (Spain) (projects CTQ2016-75671-P, MAT2017-86992-R, and MAT-80285-P and Excellence Unit "Maria de Maeztu" MDM-2015-0538) and the Ministero dell'Istruzione, dell'Università e della Ricerca (Italy). M.M. and E.T. thank the MINECO, and R.B. thanks the MIUR (project PON R&I FSE-FESR 2014-2020) for predoctoral grants. Thanks are also extended to the "Programa post-Ramón y Cajal de la Universidad de Valencia (E.P.)", the "Fondo per il finanziamento delle attivita base di ricerca" (D.A.), and the "Atracció de talent-contractes postdoctorals de la Universitat de Valencia" and "Juan de la Cierva-Incorporación-2017" programs (J.F.-S.). E.P. acknowledges the financial support of the European Research Council under the European Union's Horizon 2020 research and innovation programme/ERC grant agreement no. 814804, MOF-reactors.