22665-67-4Relevant articles and documents
Influence of Hydrogen Bond Donating Sites in UiO-66 Metal-Organic Framework for Highly Regioselective Methanolysis of Epoxides
Anbu, Nagaraj,Biswas, Shyam,Das, Aniruddha,Dhakshinamoorthy, Amarajothi,Sk, Mostakim
, (2020/02/18)
A Zr(IV)-based UiO-66 metal-organic framework (MOF) (named 1) was synthesized by employing 1-(aminomethyl)naphthalene-2-ol appended terephthalate linker and Zr(IV) salt via solvothermal method and subsequently characterized. Furthermore, the potential efficiency of activated (named 1′) form of as-synthesized MOF was investigated as an organocatalyst for the ring-opening of epoxide by methanol. The catalytic performance of 1 and 1′ was studied in the methanolysis of styrene oxide as a model substrate and the activity of 1′ was also examined with various alcohols. Under the optimized reaction conditions, the catalytic performance of 1′ reached 96 % conversion of styrene oxide to its corresponding product with 98 % regioselectivity. The reusability and stability of the catalyst were proved by recycling up to four runs in the methanolysis of styrene oxide. The Lewis acidity originating from metal nodes and hydrogen bond donating (HBD) sites in the linker is distributed homogeneously throughout the framework, thus playing crucial role in the activation of epoxide with easy accessibility.
Enhancement of CO2 Adsorption and Catalytic Properties by Fe-Doping of [Ga2(OH)2(L)] (H4L = Biphenyl-3,3′,5,5′-tetracarboxylic Acid), MFM-300(Ga2)
Krap, Cristina P.,Newby, Ruth,Dhakshinamoorthy, Amarajothi,García, Hermenegildo,Cebula, Izabela,Easun, Timothy L.,Savage, Mathew,Eyley, Jennifer E.,Gao, Shan,Blake, Alexander J.,Lewis, William,Beton, Peter H.,Warren, Mark R.,Allan, David R.,Frogley, Mark D.,Tang, Chiu C.,Cinque, Gianfelice,Yang, Sihai,Schr?der, Martin
, p. 1076 - 1088 (2016/02/09)
Metal-organic frameworks (MOFs) are usually synthesized using a single type of metal ion, and MOFs containing mixtures of different metal ions are of great interest and represent a methodology to enhance and tune materials properties. We report the synthesis of [Ga2(OH)2(L)] (H4L = biphenyl-3,3′,5,5′-tetracarboxylic acid), designated as MFM-300(Ga2), (MFM = Manchester Framework Material replacing NOTT designation), by solvothermal reaction of Ga(NO3)3 and H4L in a mixture of DMF, THF, and water containing HCl for 3 days. MFM-300(Ga2) crystallizes in the tetragonal space group I4122, a = b = 15.0174(7) ? and c = 11.9111(11) ? and is isostructural with the Al(III) analogue MFM-300(Al2) with pores decorated with -OH groups bridging Ga(III) centers. The isostructural Fe-doped material [Ga1.87Fe0.13(OH)2(L)], MFM-300(Ga1.87Fe0.13), can be prepared under similar conditions to MFM-300(Ga2) via reaction of a homogeneous mixture of Fe(NO3)3 and Ga(NO3)3 with biphenyl-3,3′,5,5′-tetracarboxylic acid. An Fe(III)-based material [Fe3O1.5(OH)(HL)(L)0.5(H2O)3.5], MFM-310(Fe), was synthesized with Fe(NO3)3 and the same ligand via hydrothermal methods. [MFM-310(Fe)] crystallizes in the orthorhombic space group Pmn21 with a = 10.560(4) ?, b = 19.451(8) ?, and c = 11.773(5) ? and incorporates μ3-oxo-centered trinuclear iron cluster nodes connected by ligands to give a 3D nonporous framework that has a different structure to the MFM-300 series. Thus, Fe-doping can be used to monitor the effects of the heteroatom center within a parent Ga(III) framework without the requirement of synthesizing the isostructural Fe(III) analogue [Fe2(OH)2(L)], MFM-300(Fe2), which we have thus far been unable to prepare. Fe-doping of MFM-300(Ga2) affords positive effects on gas adsorption capacities, particularly for CO2 adsorption, whereby MFM-300(Ga1.87Fe0.13) shows a 49% enhancement of CO2 adsorption capacity in comparison to the homometallic parent material. We thus report herein the highest CO2 uptake (2.86 mmol g-1 at 273 K at 1 bar) for a Ga-based MOF. The single-crystal X-ray structures of MFM-300(Ga2)-solv, MFM-300(Ga2), MFM-300(Ga2)·2.35CO2, MFM-300(Ga1.87Fe0.13)-solv, MFM-300(Ga1.87Fe0.13), and MFM-300(Ga1.87Fe0.13)·2.0CO2 have been determined. Most notably, in situ single-crystal diffraction studies of gas-loaded materials have revealed that Fe-doping has a significant impact on the molecular details for CO2 binding in the pore, with the bridging M-OH hydroxyl groups being preferred binding sites for CO2 within these framework materials. In situ synchrotron IR spectroscopic measurements on CO2 binding with respect to the -OH groups in the pore are consistent with the above structural analyses. In addition, we found that, compared to MFM-300(Ga2), Fe-doped MFM-300(Ga1.87Fe0.13) shows improved catalytic properties for the ring-opening reaction of styrene oxide, but similar activity for the room-temperature acetylation of benzaldehyde by methanol. The role of Fe-doping in these systems is discussed as a mechanism for enhancing porosity and the structural integrity of the parent material.
Synthesis of MTBE from isobutane using a single catalytic system based on titanium-containing ZSM-5 zeolite
Van Grieken,Ovejero,Serrano,Uguina,Melero
, p. 1145 - 1146 (2007/10/03)
A new route for the synthesis of methyl tert-butyl ether (MTBE) from isobutane using a single catalytic system is developed in the liquid phase; the key of the process relies on the use of a bifunctional material, Al-TS-1, capable of catalysing the oxidation of isobutane with H2O2 and consequently etherification with methanol.
