94 research outputs found
Complete low-barrier side-chain route for olefin formation during methanol conversion in H-SAPO-34
ChemInform Abstract: KINETIK DER DEHYDRIERUNG VON ISOPROPYLALKOHOL AN EINEM ZINKOXID-KATALYSATOR 2. MITT. VORHERSAGE VON RK.-GESCHWINDIGKEITEN
Hydrocarbon Formation from Methanol/Dimethyl Ether Over Protonated Zeolites and Molecular Sieves. New Insights From Recent Experiments
Computational Study of Isopropylbenzenium Ions
A theoretical investigation of the isopropylbenzenium
ion system
has been carried out with structures determined with B3LYP. Energies
are calculated with the high accuracy composite methods, G3 (G3B3)
and CBS (CBS-QB3). The main goal has been to resolve the following
issue: Are there any stable ion π-electron complexes of the
type C<sub>6</sub>H<sub>6</sub>/C<sub>3</sub>H<sub>7</sub><sup>+</sup> or C<sub>6</sub>H<sub>7</sub><sup>+</sup>/C<sub>3</sub>H<sub>6</sub> in this system? Two minimum points on the potential energy surface
(PES) corresponding to benzenium ion/propene complexes were found.
Due to free internal rotation, they represent only one species. The
barrier for forming an isopropylbenzenium ion from the complex is
low, so the lifetime will be short. Computation of the IR spectrum
of the complex shows that there is a very intense absorption line
due to C–H stretching, in an otherwise empty region, that may
be used to identify the complex, if present. No stable C<sub>6</sub>H<sub>6</sub>/C<sub>3</sub>H<sub>7</sub><sup>+</sup> complex was
found, but a quasi-stable species structurally corresponding to the
earlier described stable C<sub>6</sub>H<sub>6</sub>/C<sub>4</sub>H<sub>9</sub><sup>+</sup> complex was observed. A simplistic explanation
why the benzene/isopropyl cation, in contrast to benzene/<i>tert</i>-butyl cation, does not form a stable ion/π-electron complex
is given
Does an Ethene/Benzenium Ion Complex Exist? A Discrepancy between B3LYP and MP2 Predictions
The Reactivity of Molecules Trapped within the SAPO-34 Cavities in the Methanol-to-Hydrocarbons Reaction
Surface characterization of some selected zinc oxide samples III: Zinc oxide prepared by thermal decomposition of zinc oxalate
A Theoretical Investigation of the Methylation of Alkenes with Methanol over Acidic Zeolites
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