Imaging the chemical activity of single nanoparticles with optical microscopy

2018 ◽  
Vol 47 (7) ◽  
pp. 2485-2508 ◽  
Author(s):  
Wei Wang

Chemical activity of single nanoparticles can be imaged and determined by monitoring the optical signal of each individual during chemical reactions with advanced optical microscopes. It allows for clarifying the functional heterogeneity among individuals, and for uncovering the microscopic reaction mechanisms and kinetics that could otherwise be averaged out in ensemble measurements.

2019 ◽  
Author(s):  
john andraos

<p>An effective pedagogical method is presented for the visual communication of chemical reactions learned in organic chemistry undergraduate courses. The basis for the method is the preservation of the visual aspect of reactant and product structures so that the tracking of cleaved and formed chemical bonds is made self-evident. This consequently leads to improved clarity of presentation and a better understanding and grasp of proposed reaction mechanisms to explain product outcomes. The method is demonstrated for a variety of individual reaction types and synthesis plans. Various visual training exercises are also presented using ChemDraw Ultra 7.0 software and literature table of contents (TOC) graphics appearing in journal articles.</p><br>


2021 ◽  
Vol 28 (5) ◽  
pp. 1661-1668
Author(s):  
Hanbo Zheng ◽  
Enchen Yang ◽  
Xufan Li ◽  
Chenvao Liu ◽  
Zijian Wang ◽  
...  

2015 ◽  
Vol 7 (17) ◽  
pp. 6947-6959 ◽  
Author(s):  
Chun-Chi Chen ◽  
Po-Chiao Lin

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.


2002 ◽  
Vol 01 (02) ◽  
pp. 285-293 ◽  
Author(s):  
HIDEYUKI KAMISAKA ◽  
HIROKI NAKAMURA ◽  
SHINKOH NANBU ◽  
MUTSUMI AOYAGI ◽  
WENSHENG BIAN ◽  
...  

Using the accurate global potential energy surfaces for the 11A′′ and 21A′ states reported in the previous sister Paper I, detailed quantum dynamics calculations are performed for these adiabatic surfaces separately for J = 0 (J: total angular momentum quantum number). In addition to the significant overall contributions of these states to the title reactions reported in the second Paper II of this series, quantum dynamics on these excited potential energy surfaces (PES) are clarified in terms of the PES topographies, which are quite different from that of the ground PES. The reaction mechanisms are found to be strongly selective and nicely explained as vibrationally nonadiabatic transitions in the vicinity of potential ridge.


2006 ◽  
Vol 14 (2) ◽  
pp. 749 ◽  
Author(s):  
Tsung-Han Tsai ◽  
Shih-Peng Tai ◽  
Wen-Jeng Lee ◽  
Hsin-Yi Huang ◽  
Yi-Hua Liao ◽  
...  

2006 ◽  
Vol 18 (1) ◽  
pp. 015501 ◽  
Author(s):  
Fu Min Huang ◽  
Ferhat Culfaz ◽  
Frederic Festy ◽  
David Richards

2015 ◽  
Vol 16 (4) ◽  
pp. 797-810 ◽  
Author(s):  
Mary E. Anzovino ◽  
Stacey Lowery Bretz

Organic chemistry students struggle with reaction mechanisms and the electron-pushing formalism (EPF) used by practicing organic chemists. Faculty have identified an understanding of nucleophiles and electrophiles as one conceptual prerequisite to mastery of the EPF, but little is known about organic chemistry students' knowledge of nucleophiles and electrophiles. This research explored the ideas held by second-semester organic chemistry students about nucleophiles and electrophiles, finding that these students prioritize structure over function, relying primarily on charges to define and identify such species, both in general and in the context of specific chemical reactions. Contrary to faculty who view knowledge of nucleophiles and electrophiles as prerequisite to learning mechanisms and EPF, students demonstrated that they needed to know the mechanism of a reaction before they were able to assess whether the reaction involved nucleophiles and electrophiles or not.


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaoshuang Shen ◽  
Dengkang Guo ◽  
Pan Jiang ◽  
Gaiyun Li ◽  
Sheng Yang ◽  
...  

Abstract Wood properties of furfurylation can be altered by reaction mechanisms of furfuryl alcohol polymer (PFA) and cell walls. Although chemical reactions between PFA and lignin have been studied, reaction mechanisms between PFA and cell wall components, including lignin, cellulose and hemicellulose are still not comprehensively understood. In order to elucidate chemical reactions regarding PFA with wood cell walls, model compounds of main cell wall components were used to investigate its reactions with PFA by 13C NMR spectroscopy and differential scanning calorimetry (DSC). Results showed that there was no chemical bonding of PFA with either cellulose or hemicellulose. Condensations of uncrowded ring positions (meta, ortho and para) and side chains (α–C, β–C, β–OH, and γ–OH) of lignin with PFA did occur based on 13C NMR spectra. Reaction enthalpy and activation energy also confirmed the condensation reactions between lignin and PFA. This study could provide design guidelines to control the chemical reactions of PFA in cell walls and lignin and, therefore, improve the properties of furfurylated wood.


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