scholarly journals A calculational and ultraviolet photoelectron spectroscopic study of distorted amides

1998 ◽  
Vol 76 (6) ◽  
pp. 672-677 ◽  
Author(s):  
N H Werstiuk ◽  
H M Muchall ◽  
C D Roy ◽  
J Ma ◽  
R S Brown
Keyword(s):  
Photoelectron Spectroscopy ◽  
Molecular Orbitals ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Excellent Correlation ◽  
Model Compounds ◽  
Ionization Energies ◽  
Highest Occupied Molecular Orbitals ◽  
Equilibrium Geometries ◽  
Good Agreement

Distorted amides 3,4-dihydro-2-oxo-1,4-ethanoquinoline (1a), 3,4-dihydro-2-oxo-1,4-propanoquinoline (1b), 3,3,4,5-tetrahydro-2-oxo-1,5-ethanobenzazepine (1c), and 3,3,4,5-tetrahydro-2-oxo-1,5-propanobenzazepine (1d) and the model compounds 2,N-dimethyl-acetanilide (2a), 2,N,N-trimethylaniline (3), and benzoquinuclidine (4) have been studied calculationally and with He(I) ultraviolet photoelectron spectroscopy. We find good agreement between experimentally obtained ionization energies for 1b, 1c, 1d, 2a, 3, and 4 and values calculated with HAM/3 using the equilibrium geometries obtained at the HF/6-31G** level of theory. An excellent correlation between experimental ionization energies and orbital energies from Becke3LYP/6-31+G* calculations led to the characterization of the highest occupied molecular orbitals for these compounds and for 1a, whose photoelectron spectrum could not be obtained due to its reactivity in the solid state.Key words: distorted amides, He(I) photoelectron spectroscopy, Becke3LYP, molecular orbitals.

Characterization of Fluorinated Polyimide Films

1992 ◽  
Vol 264 ◽  
Author(s):  
Pradnya V. Nagarkar ◽  
Jiong Ping Lu ◽  
David Volfson ◽  
Klavs F. Jensen ◽  
Stephen D. Senturia
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polyimide Film ◽  
Binding Energies ◽  
Polyimide Films ◽  
Chemical Modifications ◽  
X Ray ◽  
Fluorinated Polyimide ◽  
Peak Assignment ◽  
Good Agreement

Abstract:X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) have been used to characterize the polyimide film based on 4,4′ hexafluoro-isopropylidene -bis pthalic anhydride (HFDA) and 4,4′ -bis (4-aminophenoxy) biphenyl (APBP). Films of varying thicknesses made from diluted precursors were studied by IR and XPS. An elemental analysis and a tentative peak assignment for C 1s in XPS is presented. The HFDA-APBP thick films are stoichiometric in composition and binding energies are in good agreement with data on hexafluorodianhydride-oxydianiline (HFDA-ODA). For thinner films, certain chemical modifications were observed at high cure temperatures.

Growth and Characterization of Epitaxial Graphene on SiC Induced by Carbon Evaporation

2010 ◽  
Vol 645-648 ◽  
pp. 593-596
Author(s):  
Ameer Al-Temimy ◽  
Christian Riedl ◽  
Ulrich Starke
Keyword(s):  
Photoelectron Spectroscopy ◽  
Epitaxial Graphene ◽  
Low Energy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Force Microscopy ◽  
Low Energy Electron Diffraction ◽  
Atomic Force ◽  
Graphene Lattice ◽  
Low Energy Electron

By carbon evaporation under ultrahigh vacuum (UHV) conditions, epitaxial graphene can be grown on SiC(0001) at significantly lower temperatures than with conventional Si sublimation. Therefore, the degradation of the initial SiC surface morphology can be avoided. The layers of graphene are characterized by low energy electron diffraction (LEED), angle resolved ultraviolet photoelectron spectroscopy (ARUPS), and atomic force microscopy (AFM). On SiC the graphene lattice is rotated by 30o in comparison to preparation by annealing in UHV alone.

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