A computational study of ethyl chloride conversion reactions catalyzed by acidic zeolites

Papayannis, Demetrios K.; Kosmas, Agnie M.

doi:10.1016/j.theochem.2010.07.007

Cited by 11 publications

(18 citation statements)

References 36 publications

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“…The increase in linebroadening is attributed to a decrease in motion for the loaded aspirin presumably due to interactions with the zeolite. In addition, the aromatic carbons in the drug loaded spectrum are shifted ~10 ppm in comparison to the physical mixture accounting for the interaction of phenyl group with the zeolite which is similar to what has been observed previously with polymeric and mesoporous silica hosts [125][126][127][128][129]. 4.4.3 Aspirin Release from HYThe release profiles for aspirin from zeolites, HY-5, HY-30 and HY-60 are shown inFigure 25a-c. Nearly complete release of aspirin is observed after ~300 minutes for HY-5.…”

supporting

confidence: 80%

“…107 In this study, a T12 cluster model (shown in Figure 26a) was used to study the close agreement with the literature results for similar clusters. 112,[115][116][117][118][119][120] After the optimization of the cluster models, aspirin (and the aspirin anion) was added to the system and was allowed to optimize by varying the distance of aspirin with the zeolitic models (Bronsted acid site). The optimized aspirin-zeolite structure is shown in Figure 26 b,c and the aspirin anion zeolite structure is shown in Figure 26d.…”

Section: Computational Resultsmentioning

confidence: 99%

“…The zeolite was represented using the zeolite T12 cluster model composed of 12 tetrahedral atoms of the framework respectively. [115][116][117] The T12 cluster was optimized at HF and DFT (B3LYP) levels of theory with 6-31+G(d,p) basis set. The vibrational frequencies for the T12 cluster models with aspirin and aspirin anion were calculated using HF level of theory.…”

Section: Theoretical Methodsmentioning

confidence: 99%

“…The peak at ~60 ppm is assigned to tetrahedral aluminum and the peak at ~0 ppm is assigned to octahedral aluminum. 70,[116][117][118][119][120][122][123][124][125][126] The absolute intensities in Figure 23 should not be compared because the samples contain different amounts of aluminum due to the different silica to alumina ratios. After loading with aspirin, the intensity of the octahedral aluminum peak decreases relative to the tetrahedral aluminum peak for HY-5, HY-30 and HY-60.…”

Section: Physicochemical Characterization Of Parent Andmentioning

confidence: 99%

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Applications of mesoporous silica and zeolites for drug delivery

Datt¹

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Zeolites and mesoporous silica were used as drug delivery systems for the loading and release of small drug molecules, aspirin and 5-fluorouracil. Different parameters were varied such as aluminum content in the zeolite, effect of distribution of functional groups and the method of surface modification in case of mesoporous silica. The effect of the aforementioned variables was studied on drug loading and release from these microporous and mesoporous systems. The drug loaded materials were extensively characterized using various physical techniques such as powder X-ray diffraction, nitrogen isotherms, infrared spectroscopy, solid state NMR and thermogravimetric analysis. Quantum calculations and molecular dynamics simulations were performed in order to validate the experimental data and also to obtain a molecular level insight of the drugs inside the pores of the host materials. Drug templated synthesis of mesoporous silica was also carried out in the presence of aspirin as the template. The aspirin templated material was characterized by aforementioned techniques and showed a sustained drug release profile. vii TABLE OF CONTENTS LIST OF TABLES .

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confidence: 80%

Section: Computational Resultsmentioning

confidence: 99%

Section: Theoretical Methodsmentioning

confidence: 99%

Section: Physicochemical Characterization Of Parent Andmentioning

confidence: 99%

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Applications of mesoporous silica and zeolites for drug delivery

Datt¹

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“…[10][11][12][13] The ONIOM methodology has been shown to be quite successful in the description of computationally time-consuming systems, by allowing the partitioning of a large cluster computation into various levels of accuracy, for example the active region treated with an advanced level of theory and the remaining region treated with an inexpensive, less accurate method. In the present work, the DFT-B3LYP, two layer ONIOM (MP2:B3LYP) and MP2 levels of theory were used.…”

Section: Methodsmentioning

confidence: 99%

Theoretical study on the nucleophilic fluoroalkylation of propylene oxide with fluorinated sulfones

Han

Liu

2013

JSCS

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The path of nucleophilic fluoroalkylation reaction of propylene oxide with PhSO2CYF- (Y=F,H, and PhSO2, respectively) in gas phase and in Et2O solvent were studied theoretically. The nucleophilic fluoroalkylation of propylene oxide with fluorinated carbanions was probed by the reactivity comparison between (benzenesulfonyl)monofluoromethyl anion (PhSO2CHF-), (benzenesulfonyl) difluoromethyl anion (PhSO2CF2-), and bis(benzenesul-fonyl) monofluoromethyl anion ((PhSO2)2CF-). The nucleophilicity reactivity order of PhSO2CYF- (Y = F, H, and PhSO2) is [(PhSO2)2CF-] > PhSO2CHF- > PhSO2CF2-, which indicates that introducing another electron-withdrawing benzenesulfonyl group is an effective way to significantly increase the nucleophilicity of the fluorinate carbanions. For comparison, we also studied the nucleophilic addition reactions of propylene oxide with chlorine substituted carbanion PhSO2CHCl-. The calculated results show that the nucleophilicity of PhSO2CYF- is better than that of PhSO2CHCl- for the ring opening reaction with propylene oxide. The calculated results are in good agreement with the available experiments

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