ChemInform Abstract: New Sequential Reactions with Single-Electron-Donating Agents

ChemInform ◽  
2010 ◽  
Vol 28 (22) ◽  
pp. no-no
Author(s):  
T. SKRYDSTRUP
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.


Author(s):  
G.Y. Fan ◽  
Bruce Mrosko ◽  
Mark H. Ellisman

A lens coupled CCD camera showing single electron sensitivity has been built for TEM applications. The design is illustrated in Fig. 1. The bottom flange of a JEM-4000EX microscope is replaced by a special flange which carries a large rectangular leaded glass window, 22 mm thick. A 20 μm thick layer of red phosphor is coated on the window, and the entire window is sputter-coated with a thin layer of Au/Pt. A two-lens relay system is used to provide efficient coupling between the image on the phosphor scintillator and the CCD imager. An f1.0 lens (Goerz optical) with front focal length 71.6 mm is used as the collector. A mirror prism, of the Amici type, is used to "bend" the optical path by 90° to prevent X-rays which may penetrate the leaded glass from hitting the CCD detector. Images may be relayed directly to the camera (1:1) or demagnified by a factor of up to 3:1 by moving the lens assembly.


1998 ◽  
Vol 168 (2) ◽  
pp. 219
Author(s):  
V.A. Krupenin ◽  
S.V. Lotkhov ◽  
H. Scherer ◽  
A.B. Zorin ◽  
F.-J. Ahlers ◽  
...  

2016 ◽  
Vol E99.C (2) ◽  
pp. 285-292 ◽  
Author(s):  
Tran THI THU HUONG ◽  
Hiroshi SHIMADA ◽  
Yoshinao MIZUGAKI

2018 ◽  
Author(s):  
Richard Kong ◽  
Mark Crimmin

<i>The formation of carbon chains by the coupling of COx (X = 1 or 2) units on transition metals is a fundamental step relevant to Fischer-Tropsch catalysis. Fischer-Tropsch catalysis produces energy dense liquid hydrocarbons from synthesis gas (CO and H2) and has been a mainstay of the energy economy since its discovery nearly a century ago. Despite detailed studies aimed at elucidating the steps of catalysis, experimental evidence for chain growth (Cn to Cn+1 ; n > 2) from the reaction of CO with metal complexes is unprecedented. In this paper, we show that carbon chains can be grown from sequential reactions of CO or CO2 with a transition metal carbonyl complex. By exploiting the cooperative effect of transition and main group metals, we document the first example of chain propagation from sequential coupling of CO units (C1 to C3 to C4), along with the first example of incorporation of CO2 into the growing carbon chain.</i><br>


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