scholarly journals The reaction of M(CO)3(Ph2PCH2CH2PPh2) (M = Fe, Ru) with parahydrogen: probing the electronic structure of reaction intermediates and the internal rearrangement mechanism for the dihydride products

2004 ◽  
pp. 3218-3224 ◽  
Author(s):  
Danièle Schott ◽  
Philip Callaghan ◽  
John Dunne ◽  
Simon B. Duckett ◽  
Cyril Godard ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Reaction Intermediates ◽  
Rearrangement Mechanism ◽  
Internal Rearrangement

scholarly journals The Electronic Structure of Several Reaction Intermediates

1966 ◽  
Vol 69 (5) ◽  
pp. 869-874 ◽  
Author(s):  
Teijiro YONEZAWA ◽  
Hideyuki KONISHI ◽  
Hiroshi KATO ◽  
Keiji MOROKUMA ◽  
Kenichi FUKUI
Keyword(s):  
Electronic Structure ◽  
Reaction Intermediates

Electronic structure and photochemical reaction intermediates of octakis(1,1,2-trimethylpropyl)octasilacubane

2000 ◽  
Vol 322 (1-2) ◽  
pp. 33-40 ◽  
Author(s):  
Hiroaki Horiuchi ◽  
Yukio Nakano ◽  
Takayoshi Matsumoto ◽  
Masafumi Unno ◽  
Hideyuki Matsumoto ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Photochemical Reaction ◽  
Reaction Intermediates

Real Time Determination of the Electronic Structure of Unstable Reaction Intermediates during Au2O3 Reduction

2013 ◽  
Vol 5 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Jakub Szlachetko ◽  
Jacinto Sá ◽  
Maarten Nachtegaal ◽  
Urs Hartfelder ◽  
Jean-Claude Dousse ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Real Time ◽  
Reaction Intermediates ◽  
Time Determination

Analyzing reactions of single mechanoenzyme molecules by light microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 426-427
Author(s):  
Jeff Gelles
Keyword(s):  
Image Processing ◽  
Reaction Mechanisms ◽  
Transient State ◽  
Nanometer Scale ◽  
Reaction Intermediates ◽  
Enzyme Molecule ◽  
Directed Movement ◽  
Enzyme Molecules ◽  
Individual Enzyme ◽  
Single Reaction

Mechanoenzymes are enzymes which use a chemical reaction to power directed movement along biological polymer. Such enzymes include the cytoskeletal motors (e.g., myosins, dyneins, and kinesins) as well as nucleic acid polymerases and helicases. A single catalytic turnover of a mechanoenzyme moves the enzyme molecule along the polymer a distance on the order of 10−9 m We have developed light microscope and digital image processing methods to detect and measure nanometer-scale motions driven by single mechanoenzyme molecules. These techniques enable one to monitor the occurrence of single reaction steps and to measure the lifetimes of reaction intermediates in individual enzyme molecules. This information can be used to elucidate reaction mechanisms and determine microscopic rate constants. Such an approach circumvents difficulties encountered in the use of traditional transient-state kinetics techniques to examine mechanoenzyme reaction mechanisms.

EELS Measurement of the Local Electronic Structure of Copper Atoms Segregated to Aluminum Grain Boundaries

1996 ◽  
Vol 54 ◽  
pp. 342-343
Author(s):  
S.J. Splinter ◽  
J. Bruley ◽  
P.E. Batson ◽  
D.A. Smith ◽  
R. Rosenberg
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Thin Layers ◽  
Nominal Composition ◽  
Spatially Resolved ◽  
Service Lifetime ◽  
Heat Treated ◽  
Probe Size ◽  
Local Electronic Structure

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

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