scholarly journals Plasmonic enhancement of molecular hydrogen dissociation on metallic magnesium nanoclusters

Nanoscale ◽  
2021 ◽  
Author(s):  
Oscar A. Douglas Gallardo ◽  
Connor Box ◽  
Reinhard Maurer
Keyword(s):  
Chemical Reactions ◽  
Molecular Hydrogen ◽  
Metal Catalysts ◽  
Chemical Transformations ◽  
Plasmonic Enhancement ◽  
Hydrogen Dissociation ◽  
Metallic Magnesium ◽  
Promising Strategy

Light-driven plasmonic enhancement of chemical reactions on metal catalysts is a promising strategy to achieve highly selective and efficient chemical transformations. The study of plasmonic catalyst materials has traditionally focused...

Biotransformation of Coumarins by Filamentous Fungi: An Alternative Way for Achievement of Bioactive Analogs

2019 ◽  
Vol 16 (6) ◽  
pp. 568-577 ◽  
Author(s):  
Jainara Santos do Nascimento ◽  
João Carlos Silva Conceição ◽  
Eliane de Oliveira Silva
Keyword(s):  
Filamentous Fungi ◽  
Chemical Reactions ◽  
Biological Activities ◽  
Chemical Transformations ◽  
Chemical Structures ◽  
Pattern Structures ◽  
Pharmacological Interest ◽  
Aspergillus Sp ◽  
The Impact ◽  
Related Compounds

Coumarins are natural 1,2-benzopyrones, present in remarkable amounts as secondary metabolites in edible and medicinal plants. The low yield in the coumarins isolation from natural sources, along with the difficulties faced by the total synthesis, make them attractive for biotechnological studies. The current literature contains several reports on the biotransformation of coumarins by fungi, which can generate chemical analogs with high selectivity, using mild and eco-friendly conditions. Prompted by the enormous pharmacological interest in the coumarin-related compounds, their alimentary and chemical applications, this review covers the biotransformation of coumarins by filamentous fungi. The chemical structures of the analogs were presented and compared with those from the pattern structures. The main chemical reactions catalyzed the insertion of functional groups, and the impact on the biological activities caused by the chemical transformations were discussed. Several chemical reactions can be catalyzed by filamentous fungi in the coumarin scores, mainly lactone ring opening, C3-C4 reduction and hydroxylation. Chunninghamella sp. and Aspergillus sp. are the most common fungi used in these transformations. Concerning the substrates, the biotransformation of pyranocoumarins is a rarer process. Sometimes, the bioactivities were improved by the chemical modifications and coincidences with the mammalian metabolism were pointed out.

Recent advance in NHC-palladium catalysis for alkynes chemistry: versatile synthesis and applications

2021 ◽  
Author(s):  
Jianxiao Li ◽  
Dan He ◽  
Zidong Lin ◽  
Wanqing Wu ◽  
Huanfeng Jiang
Keyword(s):  
Transition Metal ◽  
Palladium Catalysis ◽  
Metal Catalysts ◽  
Chemical Transformations ◽  
The Past ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

During the past decades, alkynes chemistry has attracted considerable attention owing to their unique and idiographic nucleophilic and electrophilic properties in transition-metal-catalyzed chemical transformations. Among the various metal catalysts, palladium...

Monitoring of chemical transformations by mass spectrometry

2015 ◽  
Vol 7 (17) ◽  
pp. 6947-6959 ◽  
Author(s):  
Chun-Chi Chen ◽  
Po-Chiao Lin
Keyword(s):  
Mass Spectrometry ◽  
Chemical Reactions ◽  
Reaction Mechanisms ◽  
Chemical Transformations

During the last several decades, mass spectrometry (MS) has rapidly developed as a practical technique that can be used to monitor chemical reactions and investigate reaction mechanisms.

scholarly journals Membranes for Hydrogen Purification: An Important Step toward a Hydrogen-Based Economy

MRS Bulletin ◽  
2006 ◽  
Vol 31 (10) ◽  
pp. 735-744 ◽  
Author(s):  
Tina M. Nenoff ◽  
Richard J. Spontak ◽  
Christopher M. Aberg
Keyword(s):  
Chemical Reactions ◽  
Molecular Hydrogen ◽  
Glassy Polymer ◽  
Surface Flow ◽  
Pure Hydrogen ◽  
Hydrogen Purification ◽  
High Solubility ◽  
Porous Support ◽  
Basic Principles ◽  
Molecular Sieving

AbstractProduction of pure molecular hydrogen is essential to the realization of the proposed “hydrogen economy” that could ultimately provide hydrogen as a clean, renewable source of energy; eliminate the industrialized world's dependence on petroleum; and reduce the generation of greenhouse gases linked to global warming. A crucial step in obtaining pure hydrogen is separating it from other gaseous compounds—mainly CO2—that often accompany hydrogen in industrial chemical reactions. Advanced membrane technology may prove to be the key to the successful, economical production of molecular hydrogen.Size-sieving glassy polymer membranes can separate H2 on the basis of its small size. Alternatively, reverse-selective rubbery polymers can expedite the passage and, hence, removal of CO2 due to its relatively high solubility in such membranes alone or in conjunction with dissociative chemical reactions. Transition-metal membranes and their alloys can adsorb H2 molecules, dissociate the molecules into H atoms for transport through interstitial sites, and subsequently recombine the H atoms to form molecular H2 again on the opposite membrane side. Microporous amorphous silica and zeolite membranes comprising thin films on a multilayer porous support exhibit good sorption selectivity and high diffusion mobilities for H2, leading to high H2 fluxes. Finally, carbon-based membranes, including carbon nanotubes, may be viable for H2 separation on the basis of selective surface flow and molecular sieving. A wide variety of materials challenges exist in hydrogen purification, and the objective of this issue of MRS Bulletin is to address those challenges and their potential solutions from basic principles.

First-principles study of molecular hydrogen dissociation on doped Al12X (X = B, Al, C, Si, P, Mg, and Ca) clusters

2009 ◽  
Vol 30 (15) ◽  
pp. 2509-2514 ◽  
Author(s):  
Lu Wang ◽  
Jijun Zhao ◽  
Zhen Zhou ◽  
S. B. Zhang ◽  
Zhongfang Chen
Keyword(s):  
First Principles ◽  
Molecular Hydrogen ◽  
Hydrogen Dissociation ◽  
First Principles Study
Sign in / Sign up

Export Citation Format

Share Document