scholarly journals Stability and Activity of Zn/MCM-41 Materials in Toluene Alkylation: Microwave Irradiation vs Continuous Flow

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 136 ◽  
Author(s):  
Paola M. Carraro ◽  
Bruna S. Goldani ◽  
Diego Alves ◽  
A. Gabriel Sathicq ◽  
Griselda A. Eimer ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Continuous Flow ◽  
Textural Properties ◽  
Analytical Techniques ◽  
Zinc Nitrate ◽  
Flow Conditions ◽  
Wet Impregnation ◽  
Toluene Alkylation ◽  
Full Conversion ◽  
Mcm 41

Zn/MCM-41 mesoporous materials have been prepared via classic wet impregnation, employing zinc nitrate as precursor and tested for activity and stability in the Friedel-Crafts alkylation of toluene with benzyl chloride under microwave irradiation and continuous flow. The modified materials were characterized by means of a number of analytical techniques, and surface and textural properties were thoroughly checked. Materials containing the highest Zn loading (15 wt %) provided full conversion after 5 minutes reaction under microwave irradiation (300 W, 120 °C). Materials were proved to be stable and reusable for several cycles with an optimum performance under continuous flow conditions.

Microwave-assisted immobilization of metallophthalocyanines in mesoporous channels of MCM-41

2007 ◽  
Vol 11 (02) ◽  
pp. 118-124 ◽  
Author(s):  
Mahtab Pirouzmand ◽  
Mostafa M. Amini ◽  
Nasser Safari
Keyword(s):  
Microwave Irradiation ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Short Period ◽  
Vis Spectroscopy ◽  
Adsorption Desorption ◽  
Mcm 41

Metallophthalocyanines have been assembled in MCM-41 channels by microwave irradiation of a mixture of ion-exchanged MCM-41, and 1,2-dicyanobenzene under solvent-free conditions in a considerably short period of time. The prepared materials have been characterized by diffuse reflectance UV-vis spectroscopy, X-ray powder diffraction XRD, differential scanning calorimetry DSC, and Brunauer-Emmett-Teller BET nitrogen adsorption desorption techniques. The X-ray diffraction and Brunauer-Emmett-Teller results showed that the textural properties of MCM-41 were preserved during microwave irradiation.

Metal–organic frameworks for the removal of the emerging contaminant atenolol under real conditions

2021 ◽  
Vol 50 (7) ◽  
pp. 2493-2500
Author(s):  
Sara Rojas ◽  
Jorge A. R. Navarro ◽  
Patricia Horcajada
Keyword(s):  
Continuous Flow ◽  
Metal Organic Frameworks ◽  
Fixed Bed ◽  
Emerging Contaminant ◽  
Flow Conditions ◽  
Metal Organic ◽  
Fixed Bed System

A defective Metal-Organic Frameworks as an improved material for the construction of a fixed-bed system working under continuous flow conditions for the removal of the emerging contaminant atenolol.

scholarly journals Formation and Utility of Reactive Ketene Intermediates Under Continuous Flow Conditions

Tetrahedron ◽  
2021 ◽  
pp. 132305
Author(s):  
Harry R. Smallman ◽  
Jamie A. Leitch ◽  
Tom McBride ◽  
Steven V. Ley ◽  
Duncan L. Browne
Keyword(s):  
Continuous Flow ◽  
Flow Conditions

scholarly journals Achieving selectivity in porphyrin bromination through a DoE-driven optimization under continuous flow conditions

2020 ◽  
Author(s):  
Paolo Zardi ◽  
Michele Maggini ◽  
Tommaso Carofiglio
Keyword(s):  
Reaction Time ◽  
Design Of Experiment ◽  
Continuous Flow ◽  
Optimization Process ◽  
Porphyrin Ring ◽  
Flow Conditions ◽  
Reaction Parameters ◽  
Synthetic Procedure ◽  
Relevant Factors ◽  
Post Functionalization

AbstractThe post-functionalization of porphyrins through the bromination in β position of the pyrrolic rings is a relevant transformation because the resulting bromoderivatives are useful synthons to covalently link a variety of chemical architectures to a porphyrin ring. However, single bromination of porphyrins is a challenging reaction for the abundancy of reactive β-pyrrolic positions in the aromatic macrocycle. We herein report a synthetic procedure for the efficient preparation of 2-bromo-5,10,15,20-tetraphenylporphyrin (1) under continuous flow conditions. The use of flow technology allows to reach an accurate control over critical reaction parameters such as temperature and reaction time. Furthermore, by performing the optimization process through a statistical DoE (Design of Experiment) approach, these parameters could be properly adjusted with a limited number of experiments. This process led us to a better understanding of the relevant factors that govern porphyrins monobromination and to obtain compound 1 with an unprecedent 80% yield.

scholarly journals Silica Monolith for the Removal of Pollutants from Gas and Aqueous Phases

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1316
Author(s):  
Vanessa Miglio ◽  
Chiara Zaccone ◽  
Chiara Vittoni ◽  
Ilaria Braschi ◽  
Enrico Buscaroli ◽  
...  
Keyword(s):  
Rhodamine B ◽  
Water Solution ◽  
Synthesis Method ◽  
Textural Properties ◽  
Adsorption Properties ◽  
Water Soluble ◽  
Silica Monoliths ◽  
Physico Chemical ◽  
Gaseous Toluene ◽  
Mcm 41

This study focused on the application of mesoporous silica monoliths for the removal of organic pollutants. The physico-chemical textural and surface properties of the monoliths were investigated. The homogeneity of the textural properties along the entire length of the monoliths was assessed, as well as the reproducibility of the synthesis method. The adsorption properties of the monoliths for gaseous toluene, as a model of Volatile Organic Compounds (VOCs), were evaluated and compared to those of a reference meso-structured silica powder (MCM-41) of commercial origin. Silica monoliths adsorbed comparable amounts of toluene with respect to MCM-41, with better performances at low pressure. Finally, considering their potential application in water phase, the adsorption properties of monoliths toward Rhodamine B, selected as a model molecule of water soluble pollutants, were studied together with their stability in water. After 24 h of contact, the silica monoliths were able to adsorb up to the 70% of 1.5 × 10−2 mM Rhodamine B in water solution.

Microwave-Assisted Grafting to MCM-41 Silica and its Application as Catalyst in Flow Chemistry

2011 ◽  
Vol 64 (11) ◽  
pp. 1522 ◽  
Author(s):  
Manuela Oliverio ◽  
Antonio Procopio ◽  
Toma N. Glasnov ◽  
Walter Goessler ◽  
C. Oliver Kappe
Keyword(s):  
Continuous Flow ◽  
Rate Increase ◽  
Flow Chemistry ◽  
Conventional Heating ◽  
Kinetic Effect ◽  
Microwave Technology ◽  
Microwave Assisted ◽  
Technology Control ◽  
First Time ◽  
Mcm 41

Finding environmentally gentle methods to graft Lewis acid on the surface of mesoporous materials is a topic of current interest. Herein we describe the optimization of a preparation procedure of a mesoporous silica-supported ErIII catalyst using the microwave-assisted post-calcination functionalization of Mobil Composition of Matter-41 silica as the key step. The required time for functionalization was reduced from several hours to 10 min using sealed-vessel microwave technology. Control experiments using conventional heating at the same temperature demonstrated that the rate increase is owing to a simple thermal/kinetic effect as a result of the higher reaction temperature. The resulting ErIII catalyst was tested for the first time as a catalyst in the continuous flow deprotection of benzaldehyde dimethylacetal and a complete leaching study was performed.

Ammonium formate as a green hydrogen source for clean semi-continuous enzymatic dynamic kinetic resolution of (+/−)-α-methylbenzylamine

RSC Advances ◽  
2014 ◽  
Vol 4 (26) ◽  
pp. 13620-13625 ◽  
Author(s):  
Amanda S. de Miranda ◽  
Rodrigo O. M. A. de Souza ◽  
Leandro S. M. Miranda
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Ammonium Formate ◽  
Flow Conditions ◽  
Dynamic Kinetic Resolution

The chemoenzymatic dynamic kinetic resolution of (+/−)-α-methylbenzylamine under continuous flow conditions in the presence of Pd/BaSO4as racemization catalyst and ammonium formate as reductant is described.

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