scholarly journals Controlling Complexation Behavior of Early Lanthanides via the Subtle Interplay of their Lewis Acidity with the Chemical Stability of 5,5'‐(Azobis)tetrazolide

2020 ◽  
Vol 646 (23-24) ◽  
pp. 1882-1885
Author(s):  
Peter Weinberger ◽  
Gerald Giester ◽  
Georg Steinhauser
2018 ◽  
Author(s):  
Felix Hemmann ◽  
Jonathan Hackebeil ◽  
Andreas Lißner ◽  
Florian Mertens

Molecular sieves with beta zeolite topology are promising catalysts for various reactions as they exhibits extraordinary Lewis acidity. However, their industrial application and related research in academica is hindered because their synthesis is time consuming and typically involves toxic chemicals as hydrofluoric acid. Therefore, tetraethylammonium fluorid was tested as a non-toxic fluotide source for the synthesis of beta zeolites. In combination with the previously reported nano-seeded growth method, a fast synthesis of beta zeolites only involving non-toxic chemicals was possible. Synthesized zeolites show comparable selectivity in the Bayer-Villinger oxidation as conventional zeolites synthesized with hydrofluoric acid.<br>


2000 ◽  
Author(s):  
Vandana Vij ◽  
Ashwani Vij ◽  
William W. Wilson ◽  
Karl O. Christe ◽  
Jeffery A. Sheehy
Keyword(s):  

1999 ◽  
Author(s):  
Karl O. Christe ◽  
David A. Dixon ◽  
Douglas McLemore ◽  
William W. Wilson ◽  
Jeffrey A. Sheehy

2019 ◽  
Vol 16 (9) ◽  
pp. 740-749
Author(s):  
Sushil R. Mathapati ◽  
Arvind H. Jadhav ◽  
Mantosh B. Swami ◽  
Jairaj K. Dawle

Zinc sulfamate (Zn(NH2SO3)2 is a derivative of sulfamic acid (H3NSO3) which possesses “Lewis acidity” and finds well suited in a number of catalytic applications. The present paper describes an efficient, eco-friendly, and clean synthesis of 2-substituted benzimidazole derivatives by reacting diverse o-phenylenediamine with various substituted aromatic aldehydes using a catalytic amount of zinc sulfamate in ethanol at ambient temperature. As a result, 10 mol.% of Zinc sulfamate catalyst showed 92% of respective product yield with 100% conversion using short reaction period in ethanol. Meanwhile, effect of reaction parameters, such as amount of catalyst, different solvents, and reaction temperature on reaction product, was also studied. In addition, in the optimized reaction condition various substituted biological important benzimidazoles derivatives were prepared by using optimized reaction condition in good to efficient yield. In addition, possible reaction mechanism in the presence of zinc sulfamate for the preparation of benzimidazole derivative was sketched and discussed. The present green approach showed significances with faster reaction rate with inexpensive catalyst, which showed excellent and clean yield of benzimidazole in mild reaction condition with easy work-up procedure.


2018 ◽  
pp. 1656-1662 ◽  
Author(s):  
Mojtaba Raeisi ◽  
Mohammad Hashemi ◽  
Majid Aminzare ◽  
Asma Afshari ◽  
Tayebeh Zeinali ◽  
...  

Background and Aim: Extending the shelf life of foods is an essential concept in food safety. Most of the time, foods deteriorate through the growth of microorganisms or oxidation process. Essential oils (EOs) derived from plant material have well-documented antioxidant and antibacterial activity. This study aimed to evaluate the effect of Zataria multiflora Boiss EO (ZEO) and Mentha piperita EO (MEO) on the chemical stability of minced meat during storage at 7°C. Materials and Methods: Total phenolic content, β-Carotene bleaching test, ferric reducing antioxidant potential assay, and 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity were used to determine the antioxidant potential of EOs. Five different groups including control, ZEO 0.3%, ZEO 0.5%, MEO 0.3%, and MEO 0.5% were designed to assess the chemical stability of minced meat by measuring pH, thiobarbituric acid (TBA), total volatile base nitrogen (TVBN), and peroxide value (PV). Results: pH did not have any significant change during storage. TBA values in the control group were significantly higher than the treatment groups, especially from the 5th day of storage. TVBN in the treatment group was significantly lower than the control group during storage. PV values in the treatment group were significantly lower than the control group during storage. Conclusion: Results indicate that ZEO and MEO had an excellent antioxidant activity and retarded the spoilage process in minced meat. Keywords: antioxidant, Mentha piperita, minced meat, Zataria multiflora Boiss.


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