2979-22-8Relevant academic research and scientific papers
Size selectivity of a copper metal-organic framework and origin of catalytic activity in epoxide alcoholysis
Jiang, Dongmei,Urakawa, Atsushi,Yulikov, Maxim,Mallat, Tamas,Jeschke, Gunnar,Baiker, Alfons
, p. 12255 - 12262 (2009)
{(Cu(bpy)(H2O)2(BF4)2(bpy)} (Cu-MOF; MOF = metal-organic framework; bpy = 4,4'-bipyridine), with a 3D-interpenetrated structure and saturated Cu coordination sites in the framework, possesses unexpectedly high a
Lanthanide-polyphosphonate coordination polymers combining catalytic and photoluminescence properties
Vilela, Sergio M. F.,Firmino, Ana D. G.,Mendes, Ricardo F.,Fernandes, Jose A.,Ananias, Duarte,Valente, Anabela A.,Ott, Holger,Carlos, Luis D.,Rocha, Joao,Tome, Joao P. C.,Almeida Paz, Filipe A.
, p. 6400 - 6402 (2013)
A rapid, mild and high-yield microwave synthesis of 1D isotypical [Ln(H4bmt)(H5bmt)(H2O)2] ·3H2O coordination polymers is presented. The La 3+-based material is highly active as a heterogen
Cr-MIL-101 encapsulated Keggin phosphotungstic acid as active nanomaterial for catalysing the alcoholysis of styrene oxide
Wee, Lik H.,Bonino, Francesca,Lamberti, Carlo,Bordiga, Silvia,Martens, Johan A.
, p. 1351 - 1357 (2014)
Mesoporous chromium-based terephthalate metal-organic framework (MIL-101) encapsulated Keggin phosphotungstic acid (HPW) [MIL-101(HPW)] was demonstrated to be an active heterogeneous catalyst for selective catalysis of the ring opening reaction of styrene
Multifunctionality and cytotoxicity of a layered coordination polymer
Almeida Paz, Filipe A.,Ananias, Duarte,Borges, Fernanda,Fernandes, Carlos,Gomes, Ana C.,Mendes, Ricardo F.,Remia?, Fernando,Silva, Patrícia,Valente, Anabela A.
, p. 3989 - 3998 (2020)
This work reports the synthesis and multifunctionality of 2D layered coordination polymers formulated as [Ln2(H3nmp)2]·xH2O (1, where Ln = Sm3+, Eu3+, Tb3+, Dy3+, Hos
Sulfur and iron co-doped titanoniobate nanosheets: A novel efficient solid acid catalyst for alcoholysis of styrene epoxide at room temperature
Zhang, Lihong,Hu, Chenhui,Zhang, Junfeng,Cheng, Liyuan,Zhai, Zheng,Chen, Jing,Ding, Weiping,Hou, Wenhua
, p. 7507 - 7509 (2013)
Sulfur and iron co-doped titanoniobate nanosheets were prepared and evaluated in alcoholysis of styrene epoxide. The resultant co-doped catalyst exhibited excellent catalytic performance (yield of 99% with methanol as the nucleophile in only 1 h at room temperature) and may act as a promising candidate in many acid-catalyzed reactions.
Thermal transformation of a layered multifunctional network into a metal-organic framework based on a polymeric organic linker
Silva, Patricia,Vieira, Fabiana,Gomes, Ana C.,Ananias, Duarte,Fernandes, Jose A.,Bruno, Sofia M.,Soares, Rosario,Valente, Anabela A.,Rocha, Joao,Paz, Filipe A. Almeida
, p. 15120 - 15138 (2011)
The preparation of layered [La(H3nmp)] as microcrystalline powders from optimized microwave-assisted synthesis or dynamic hydrothermal synthesis (i.e., with constant rotation of the autoclaves) from the reaction of nitrilotris(methylenephosphonic acid) (H6nmp) with LaCl 3?7H2O is reported. Thermogravimetry in conjunction with thermodiffractometry showed that the material undergoes a microcrystal-to-microcrystal phase transformation above 300 °C, being transformed into either a three-dimensional or a two-dimensional network (two models are proposed based on dislocation of molecular units) formulated as [La(L)] (where L3- = [-(PO3CH2) 2(NH)(CH2PO2)O1/2-]n 3n-). The two crystal structures were solved from ab initio methods based on powder X-ray diffraction data in conjunction with structural information derived from 13C and 31P solid-state NMR, electron microscopy (SEM and EDS mapping), FT-IR spectroscopy, thermodiffractometry, and photoluminescence studies. It is shown that upon heating the coordinated H3nmp3- anionic organic ligand undergoes a polymerization (condensation) reaction to form in situ a novel and unprecedented one-dimensional polymeric organic ligand. The lanthanum oxide layers act, thus, simultaneously as insulating and templating two-dimensional scaffolds. A rationalization of the various steps involved in these transformations is provided for the two models. Photoluminescent materials, isotypical with both the as-prepared ([(La0.95Eu0.05) (H3nmp)] and [(La0.95Tb0.05)(H 3nmp)]) and the calcined ([(La0.95Eu0.05)(L)]) compounds and containing stoichiometric amounts of optically active lanthanide centers, have been prepared and their photoluminescent properties studied in detail. The lifetimes of Eu3+ vary between 2.04 ± 0.01 and 2.31 ± 0.01 ms (considering both ambient and low-temperature studies). [La(H3nmp)] is shown to be an effective heterogeneous catalyst in the ring opening of styrene oxide with methanol or ethanol, producing 2-methoxy-2-phenylethanol or 2-ethoxy-2-phenylethanol, respectively, in quantitative yields in the temperature range 40-70 °C. The material exhibits excellent regioselectivity to the β-alkoxy alcohol products even in the presence of water. Catalyst recycling and leaching tests performed for [La(H3nmp)] confirm the heterogeneous nature of the catalytic reaction. Catalytic activity may be attributed to structural defect sites. This assumption is somewhat supported by the much higher catalytic activity of [La(L)] in comparison to [La(H3nmp)].
Sulfated Carbon Quantum Dots as Efficient Visible-Light Switchable Acid Catalysts for Room-Temperature Ring-Opening Reactions
Li, Haitao,Sun, Chenghua,Ali, Muataz,Zhou, Fengling,Zhang, Xinyi,MacFarlane, Douglas R.
, p. 8420 - 8424 (2015)
Acid catalytic processes play a classic and important role in modern organic synthesis. How well the acid can be controlled often plays the key role in the controllable synthesis of the products with high conversion yield and selectivity. The preparation of a novel, photo-switchable solid-acid catalyst based on carbon quantum dots is described. The carbon quantum dots are decorated with small amounts of hydrogensulfate groups and thus exhibit a photogenerated acidity that produces a highly efficient acid catalysis of the ring opening of epoxides with methanol and other primary alcohols. This reversible, light-switchable acidity is shown to be due to photoexcitation and charge separation in the carbon quantum dots, which create an electron withdrawing effect from the acidic groups. The catalyst is easily separated by filtration, and we demonstrate multiple cycles of its recovery and reuse.
Multi-functional metal-organic frameworks assembled from a tripodal organic linker
Vilela, Sergio M. F.,Ananias, Duarte,Gomes, Ana C.,Valente, Anabela A.,Carlos, Luis D.,Cavaleiro, Jose A. S.,Rocha, Joao,Tome, Joao P. C.,Almeida Paz, Filipe A.
, p. 18354 - 18371 (2012)
The reaction between (benzene-1,3,5-triyltris(methylene))triphosphonic acid (H6bmt) and lanthanide chlorides, under typical hydrothermal conditions (180 °C for 3 days) or using microwave heating (5 minutes above 150 °C), led to the isolation of
Microporous Nanotubes and Nanospheres with Iron-Catechol Sites: Efficient Lewis Acid Catalyst and Support for Ag Nanoparticles in CO2 Fixation Reaction
Modak, Arindam,Bhanja, Piyali,Bhaumik, Asim
, p. 14189 - 14197 (2018)
FeIII-containing hyper-crosslinked microporous nanotubes (FeNTs) and nanospheres (FeNSs) are synthesized through the reaction of catechol and dimethoxymethane in the presence of FeCl3 or CF3SO3H. Both FeNTs and FeNSs demonstrate excellent catalytic activity in Lewis acid catalysis (hydrolysis and regioselective methanolysis of styrene oxide) and tandem catalysis involving a sequential oxidation-cyclization process, which selectively converts benzyl alcohol to 2-phenyl benzimidazole. Apart from Lewis acidity, the FeNTs and FeNSs also showed CO2 uptake capacities of 2.6 and 2.2 mmol g?1, respectively, at a pressure of 1 atm and temperature of 273 K. Furthermore, Ag nanoparticles are immobilized successfully on the surfaces of FeNTs and FeNSs by the liquid-phase impregnation method to prepare Ag@FeNT and Ag@FeNS nanocomposites, which show high catalytic activity for the selective fixation of CO2 to phenylacetylene to yield phenylpropiolic acid at 60 °C and 1 atm CO2 pressure. Hence, FeIII-catechol-containing hyper-crosslinked nanotubes and nanospheres have huge potential not only as Lewis acid catalysts, but also as excellent supports for immobilizing Ag nanoparticles in the design of a robust catalyst for the carboxylation of terminal alkynes, which has wide scope in catalysis and environmental research.
A copper-phosphonate network as a high-performance heterogeneous catalyst for the CO2 cycloaddition reactions and alcoholysis of epoxides
Ai, Jing,Min, Xue,Gao, Chao-Ying,Tian, Hong-Rui,Dang, Song,Sun, Zhong-Ming
, p. 6756 - 6761 (2017)
A novel 3D copper-phosphonate network, with the general formula Cu7(H1L)2(TPT)3(H2O)6, namely compound 1, has been synthesized using a rigid tetrahedral linker tetraphenylsilane tetrakis-4-
