Search results for "Catalysis"
showing 10 items of 5944 documents
Permanent Porosity in Hydroxamate Titanium-Organic Polyhedra.
2021
Following the synthesis of hydroxamate titanium–organic frameworks, we now extend these siderophore-type linkers to the assembly of the first titanium–organic polyhedra displaying permanent porosity. Mixed-linker versions of this molecular cage (cMUV-11) are also used to demonstrate the effect of pore chemistry in accessing high surface areas of near 1200 m2·g–1.
A Theoretical Determination of the Low-lying Electronic States of the p-Benzosemiquinone Radical Anion
2000
The low-lying electronic states of the p-benzosemiquinone radical anion are studied using multiconfigurational second-order perturbation theory (CASPT2) and extended atomic natural orbital (ANO) ba...
Synthesis, photochemistry, and electrochemistry of (P)Ge(R)2 and (P)Ge(R)X (P = TPP or OEP, R = CH3, CH2C6H5, or C6H5, and X = Cl-, OH-, or ClO4-)
1987
Chaque complexe est caracterise par spectroscopie RMN de H1, UV-visible, IR et aussi par l'etude electrochimique
Toward an Understanding of Molecular Mechanism of Domino Cycloadditions. Density Functional Theory Study of the Reaction between Hexafluorobut-2-yne …
1998
The Cone-to-Cone Interconversion of Partially O-Methylated Calix[4]arenes: First Experimental Values for the Energy Barriers
1999
Meltable, Glass-Forming, Iron Zeolitic Imidazolate Frameworks
2023
MOF-Triggered Synthesis of Subnanometer Ag02 Clusters and Fe3+ Single Atoms: Heterogenization Led to Efficient and Synergetic One-Pot Catalytic React…
2023
Metal Node Control of Brønsted Acidity in Heterobimetallic Titanium–Organic Frameworks
2023
Compared to indirect framework modification, synthetic control of cluster composition can be used to gain direct access to catalytic activities exclusive of specific metal combinations. We demonstrate this concept by testing the aminolysis of epoxides with a family of isostructural mesoporous frameworks featuring five combinations of homometallic and heterobimetallic metal-oxo trimers (Fe3, Ti3, TiFe2, TiCo2, and TiNi2). Only TiFe2 nodes display activities comparable to benchmark catalysts based on grafting of strong acids, which here originate from the combination of Lewis Ti4+ and Brønsted Fe3+–OH acid sites. The applicability of MUV-101(Fe) to the synthesis of β-amino a…
Semiconductor Porous Hydrogen-Bonded Organic Frameworks Based on Tetrathiafulvalene Derivatives.
2022
Herein, we report on the use of tetrathiavulvalene-tetrabenzoic acid, H4TTFTB, to engender semiconductivity in porous hydrogen-bonded organic frameworks (HOFs). By tuning the synthetic conditions, three different polymorphs have been obtained, denoted MUV-20a, MUV-20b, and MUV-21, all of them presenting open structures (22, 15, and 27%, respectively) and suitable TTF stacking for efficient orbital overlap. Whereas MUV-21 collapses during the activation process, MUV-20a and MUV-20b offer high stability evacuation, with a CO2 sorption capacity of 1.91 and 1.71 mmol g-1, respectively, at 10 °C and 6 bar. Interestingly, both MUV-20a and MUV-20b present a zwitterionic character with a positively…