Design of stable mixed-metal MIL-101(Cr/Fe) materials with enhanced catalytic activity for the Prins reaction
[EN] This work highlights the benefit of designing mixed-metal (Cr/Fe) MOFs for enhanced chemical stability and catalytic activity. A robust and stable mixed-metal MIL-101(Cr/Fe) was prepared through a HF-free direct hydrothermal route with Fe(3+)content up to 21 wt%. The incorporation of Fe(3+)cations in the crystal structure was confirmed by(57)Fe Mossbauer spectrometry. The catalytic performance of the mixed metal MIL-101(Cr/Fe) was evaluated in the Prins reaction. MIL-101(Cr/Fe) exhibited a higher catalytic activity compared to MIL-101(Cr), improved chemical stability compared to MIL-101(Fe) and a higher catalytic activity for bulky substrates compared to MIL-100(Fe).In situinfra-red sp…
Exploring the catalytic performance of a series of bimetallic MIL-100(Fe, Ni) MOFs
[EN] A series of mixed-metal Fe-III/Ni-II metal-organic frameworks (MOFs) of the MIL-100 type containing different metal ratios have been synthesized de novo, following an approach that requires tuning of the Fe-III/Ni-II reactivity. The resulting heterometallic MIL-100(Fe, Ni) materials maintain thermal, chemical and structural stability with respect to the parent MIL-100(Fe) MOF as can be deduced from various techniques. The nature and the oxidation state of the accessible metal cations have been evaluated by in situ infrared spectroscopy and extended X-ray absorption fine structure measurements. The obtained mixed-metal MOFs and the parent material have been evaluated as heterogeneous ca…
White light emitting silsesquioxane based materials: the importance of a ligand with rigid and directional arms
The synthesis of a novel polyhedral oligomeric silsesquioxane functionalized with eight rigid and directional terpyridine-based arms (Ter-POSS) was successfully achieved via a Sonogashira reaction. The POSS based ligand was extensively characterized using different techniques including 1H, 13C and 29Si NMR as well as UV-Vis and fluorescence spectroscopies. The assembly of these nano-caged units in the presence of different transition metal ions (Fe2+, Zn2+ and Cu2+) as well as of a cation from the lanthanides (Eu3+) was investigated using absorption and emission spectroscopies. The final materials display an evident emission in different regions of the visible spectrum as a function of the …
A highly stable and hierarchical tetrathiafulvalene-based metal organic framework with improved performance as a solid catalyst
[EN] Herein we report the synthesis of a tetrathiafulvalene (TTF)-based MOF, namely MUV-2, which shows a non-interpenetrated hierarchical crystal structure with mesoporous one-dimensional channels of ca. 3 nm and orthogonal microporous channels of ca. 1 nm. This highly stable MOF (aqueous solution with pH values ranging from 2 to 11 and different organic solvents), which possesses the well-known [Fe3(¿3-O)(COO)6] secondary building unit, has proven to be an efficient catalyst for the aerobic oxidation of dibenzothiophenes.
Carbon nanotube supported aluminum porphyrin-imidazolium bromide crosslinked copolymer
The increased awareness of the catastrophic consequences caused by the accumulation of greenhouse gases into the atmosphere has generated a large mobilization aimed at CO2 mitigation. Herein, in the spirit of the transformation of a waste as CO2 into value added products, we propose an efficient preparation of two different hybrid systems based on aluminum chloride tetrastyrylporphyrin (TSP-Al-Cl) and 1,4-butanediyl-3,3′-bis-1-vinylimidazolium dibromide copolymerized in the presence (MWCNT-TSP-AlCl-imi) and in absence (TSP-AlCl-imi) of multi-walled carbon nanotubes (MWCNTs) for the CO2 utilization in the synthesis of cyclic carbonates. The so-prepared materials have been thoroughly characte…
POSS-Al-porphyrin-imidazolium cross-linked network as catalytic bifunctional platform for the conversion of CO2 with epoxides
Two heterogeneous catalysts were prepared with the aim of following the promising path of CO2 fixation into epoxides. The synthetic procedure involves a radical copolymerization of an octavinylsilsesquioxane as inorganic core building block and tetrastyrylporphyrin aluminum chloride monomer (TSP-AlCl) in presence (POSS-TSP-AlCl-imiBr) or in absence (POSS-TSP-AlCl) of a bis-vinylimidazolium bromide salt (bis-imiBr), in order to investigate if the bifunctional heterogeneous material can display better catalytic performance than the separate species. All the solids were fully characterized and tested in the synthesis of cyclic carbonates starting from CO2 and several epoxides. The synergic coo…
CCDC 1579606: Experimental Crystal Structure Determination
Related Article: Manuel Souto, Andrea Santiago-Portillo, Miguel Palomino, Iñigo J. Vitórica-Yrezábal, Bruno J. C. Vieira, João C. Waerenborgh, Susana Valencia, Sergio Navalón, Fernando Rey, Hermenegildo García, Guillermo Mínguez Espallargas|2018|Chemical Science|9|2413|doi:10.1039/C7SC04829G