N-Iodo-amides: mechanism of intramolecular reactions with aromatic rings of amido-radicals in Σ- and Π-electronic states

1977 ◽  
pp. 1348-1356 ◽  
Author(s):  
Stephen A. Glover ◽  
André Goosen
Keyword(s):  
Electronic States ◽  
Aromatic Rings ◽  
Intramolecular Reactions

ELEMENTARY EXCITATIONS AND OPTICAL ABSORPTION IN A POLYACENE CHAIN

2003 ◽  
Vol 17 (10) ◽  
pp. 2023-2034 ◽  
Author(s):  
Z. AN ◽  
C. Q. WU
Keyword(s):  
Optical Absorption ◽  
Tight Binding ◽  
Electronic States ◽  
Open Boundary ◽  
Aromatic Rings ◽  
Open Boundary Condition ◽  
Elementary Excitations ◽  
Strongly Coupled ◽  
Valence Bands ◽  
Doubly Charged

Within a tight-binding Su–Schrieffer–Heeger model, the elementary excitations and optical absorption of a polyacene chain are investigated. The polyacene chain composed of a number of aromatic rings is considered as two strongly coupled polyacetylene chains with an open boundary condition. First of all we found an interchain-coupled neutral soliton in a pristine chain as a consequence of odd-number sites in each chain. There are two localized electronic states accompanying the soliton and appearing in the conduction and valence bands, respectively. Moreover, an injected electron or hole will induce a polaron-like deformation mixed with the interchain soliton, while two extra electrons or holes will result in three separate solitons, among which one is doubly charged and other two are neutral. The optical absorption due to these elementary excitations are obtained.

Intramolecular reactions of 2-indolylacyl radicals: cyclisation upon aromatic rings

2004 ◽  
Vol 45 (29) ◽  
pp. 5605-5609 ◽  
Author(s):  
M.-Lluı̈sa Bennasar ◽  
Tomàs Roca ◽  
Francesc Ferrando
Keyword(s):  
Aromatic Rings ◽  
Intramolecular Reactions

Intramolecular Reactions of 2-Indolylacyl Radicals: Cyclization upon Aromatic Rings.

ChemInform ◽  
2004 ◽  
Vol 35 (44) ◽  
Author(s):  
M.-Lluisa Bennasar ◽  
Tomas Roca ◽  
Francesc Ferrando
Keyword(s):  
Aromatic Rings ◽  
Intramolecular Reactions

Chemical and orientational imaging of polymeric samples

1994 ◽  
Vol 52 ◽  
pp. 68-69
Author(s):  
H. Ade ◽  
B. Hsiao ◽  
G. Mitchell ◽  
E. Rightor ◽  
A. P. Smith ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Carbonyl Groups ◽  
Aromatic Rings ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
Polymeric Samples ◽  
X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

1996 ◽  
Vol 54 ◽  
pp. 154-155
Author(s):  
E. G. Rightor
Keyword(s):  
Excited State ◽  
Polymer Blends ◽  
Gas Phase ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Electronic States ◽  
Core Electron ◽  
Bulk Solids ◽  
Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

Electronic States near the Fermi Level in the Antiferromagnetic and Ferromagnetic Spinels of Zn 1− x Cu x Cr 2 Se 4 ; 0.0 ≤ x ≤ 1.0

2002 ◽  
Vol 75 (4-5) ◽  
pp. 359-371
Author(s):  
M. Hidaka ◽  
N. Tokiwa ◽  
M. Yoshimura ◽  
H. Fujii ◽  
Jae-Young Choi ◽  
...  
Keyword(s):  
Fermi Level ◽  
Electronic States

Electronic states of the Cs+ ion

1997 ◽  
Vol 94 ◽  
pp. 1794-1801 ◽  
Author(s):  
C Destandau ◽  
G Chambaud ◽  
P Rosmus
Keyword(s):  
Electronic States
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