A Study To Control Chemical Reactions Using Si:2p Core Ionization: Site-Specific Fragmentation

2011 ◽  
Vol 115 (32) ◽  
pp. 8822-8831 ◽  
Author(s):  
Shin-ichi Nagaoka ◽  
Hironobu Fukuzawa ◽  
Georg Prümper ◽  
Mai Takemoto ◽  
Osamu Takahashi ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Site Specific ◽  
Control Chemical

scholarly journals A chemical reaction controlled by light-activated molecular switches based on hetero-cyclopentanediyls

2019 ◽  
Vol 10 (12) ◽  
pp. 3486-3493 ◽  
Author(s):  
Jonas Bresien ◽  
Thomas Kröger-Badge ◽  
Stefan Lochbrunner ◽  
Dirk Michalik ◽  
Henrik Müller ◽  
...  
Keyword(s):  
Small Molecules ◽  
Computational Methods ◽  
Chemical Reactions ◽  
Chemical Reaction ◽  
Molecular Switches ◽  
Control Chemical

Biradicals were applied as molecular switches to control chemical reactions that involve the activation of small molecules. The mechanism was studied by experimental and computational methods.

A multi target approach to control chemical reactions in their inhomogeneous solvent environment

2015 ◽  
Vol 48 (23) ◽  
pp. 234003 ◽  
Author(s):  
Daniel Keefer ◽  
Sebastian Thallmair ◽  
Julius P P Zauleck ◽  
Regina de Vivie-Riedle
Keyword(s):  
Chemical Reactions ◽  
Control Chemical ◽  
Solvent Environment

scholarly journals Modulation of Prins Cyclization by Vibrational Strong Coupling

2019 ◽  
Author(s):  
Kenji Hirai ◽  
Rie Takeda ◽  
JAMES HUTCHISON ◽  
Hiroshi Uji-i
Keyword(s):  
Strong Coupling ◽  
Chemical Reactions ◽  
Reaction Pathway ◽  
Chemical Reactivity ◽  
Order Rate Constant ◽  
Pharmaceutical Chemistry ◽  
Prins Cyclization ◽  
Control Chemical ◽  
Aldehydes And Ketones ◽  
Enthalpy And Entropy

<div>Light-molecule strong coupling has emerged within the last decade as an entirely new method to control chemical reactions. A few years ago it was discovered that the chemical reactivity could be altered by vibrational strong coupling (VSC). While the potential of VSC in organic chemistry appears enormous, only a limited number of reactions have been investigated under VSC to date, including solvolysis and deprotection reactions. Here we investigate the effect of VSC on a series of aldehydes and ketones undergoing Prins cyclization, an important synthetic step in pharmaceutical chemistry. We observe a decrease of the second-order rate constant with VSC of the reactant carbonyl stretching groups. We measure an increased activation energy due to VSC, but proportional changes in activation enthalpy and entropy suggest no substantive change in reaction pathway. The addition of common cycloaddition reactions to the stable of VSC-modified chemical reactions is another step towards establishing VSC as a genuine tool for synthetic chemistry.</div>

scholarly journals A tutored discourse on microcontrollers, single board computers and their applications to monitor and control chemical reactions

2020 ◽  
Vol 5 (2) ◽  
pp. 201-220 ◽  
Author(s):  
Daniel E. Fitzpatrick ◽  
Matthew O'Brien ◽  
Steven V. Ley
Keyword(s):  
Low Power ◽  
Chemical Reactions ◽  
Control Chemical ◽  
And Control ◽  
Monitor And Control

This Tutored Discourse constitutes a preliminary exposure on how synthesis chemists can engage positively with inexpensive, low-power microcontrollers to aid control, monitoring and optimisation of chemical reactions.

scholarly journals Comparison of alkene hydrogenation in carbon nanoreactors of different diameters: probing the effects of nanoscale confinement on ruthenium nanoparticle catalysis

2017 ◽  
Vol 5 (40) ◽  
pp. 21467-21477 ◽  
Author(s):  
Mehtap Aygün ◽  
Craig T. Stoppiello ◽  
Maria A. Lebedeva ◽  
Emily F. Smith ◽  
Maria del Carmen Gimenez-Lopez ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Optimum Level ◽  
Control Chemical ◽  
Competitive Hydrogenation ◽  
Hydrogenation Reactions ◽  
Alkene Hydrogenation ◽  
Nanoparticle Catalysis ◽  
Different Diameters

Exploratory, competitive hydrogenation reactions reveal the optimum level of confinement to control chemical reactions.

scholarly journals Modulation of Prins Cyclization by Vibrational Strong Coupling

2019 ◽  
Author(s):  
Kenji Hirai ◽  
Rie Takeda ◽  
JAMES HUTCHISON ◽  
Hiroshi Uji-i
Keyword(s):  
Strong Coupling ◽  
Chemical Reactions ◽  
Reaction Pathway ◽  
Chemical Reactivity ◽  
Order Rate Constant ◽  
Pharmaceutical Chemistry ◽  
Prins Cyclization ◽  
Control Chemical ◽  
Aldehydes And Ketones ◽  
Enthalpy And Entropy

<div>Light-molecule strong coupling has emerged within the last decade as an entirely new method to control chemical reactions. A few years ago it was discovered that the chemical reactivity could be altered by vibrational strong coupling (VSC). While the potential of VSC in organic chemistry appears enormous, only a limited number of reactions have been investigated under VSC to date, including solvolysis and deprotection reactions. Here we investigate the effect of VSC on a series of aldehydes and ketones undergoing Prins cyclization, an important synthetic step in pharmaceutical chemistry. We observe a decrease of the second-order rate constant with VSC of the reactant carbonyl stretching groups. We measure an increased activation energy due to VSC, but proportional changes in activation enthalpy and entropy suggest no substantive change in reaction pathway. The addition of common cycloaddition reactions to the stable of VSC-modified chemical reactions is another step towards establishing VSC as a genuine tool for synthetic chemistry.</div>

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Large-cluster and combined fluorescent and gold immunoprobes

1996 ◽  
Vol 54 ◽  
pp. 892-893
Author(s):  
Richard D. Powell ◽  
James F. Hainfeld ◽  
Carol M. R. Halsey ◽  
David L. Spector ◽  
Shelley Kaurin ◽  
...  
Keyword(s):  
Metal Cluster ◽  
Sulfonyl Chloride ◽  
Gel Filtration ◽  
Cross Linking ◽  
Site Specific ◽  
Fab Fragments ◽  
Cluster Label ◽  
Covalently Linked ◽  
Texas Red ◽  
Fold Excess

Two new types of covalently linked, site-specific immunoprobes have been prepared using metal cluster labels, and used to stain components of cells. Combined fluorescein and 1.4 nm “Nanogold” labels were prepared by using the fluorescein-conjugated tris (aryl) phosphine ligand and the amino-substituted ligand in the synthesis of the Nanogold cluster. This cluster label was activated by reaction with a 60-fold excess of (sulfo-Succinimidyl-4-N-maleiniido-cyclohexane-l-carboxylate (sulfo-SMCC) at pH 7.5, separated from excess cross-linking reagent by gel filtration, and mixed in ten-fold excess with Goat Fab’ fragments against mouse IgG (obtained by reduction of F(ab’)2 fragments with 50 mM mercaptoethylamine hydrochloride). Labeled Fab’ fragments were isolated by gel filtration HPLC (Superose-12, Pharmacia). A combined Nanogold and Texas Red label was also prepared, using a Nanogold cluster derivatized with both and its protected analog: the cluster was reacted with an eight-fold excess of Texas Red sulfonyl chloride at pH 9.0, separated from excess Texas Red by gel filtration, then deprotected with HC1 in methanol to yield the amino-substituted label.

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