The experimental electronic and vibrational spectra of fulvene

1970 ◽  
Vol 23 (9) ◽  
pp. 1707 ◽  
Author(s):  
RD Brown ◽  
PJ Domaille ◽  
JE Kent
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Gas Phase ◽  
Energy Transition ◽  
Liquid Nitrogen Temperature ◽  
Electronic Transitions ◽  
Mo Calculations ◽  
Polycrystalline Layer ◽  
Partial Analysis ◽  
Electronic And Vibrational Spectra

The infrared spectrum of fulvene has been observed from 250 to 4000 cm-1 in the gas phase, and as a glass and a polycrystalline layer at liquid nitrogen temperature. On the basis of gas-phase contours and P-R separations 14 of the 30 fundamental vibrations have been assigned. The electronic absorption spectrum of fulvene has been recorded from 400 to 167 nm in the gas phase and four electronic transitions have been identified. The lowest-energy transition was found to be broad and structureless while the three higher-energy transitions showed an extensive vibrational fine structure. The electronic transitions have been tentatively assigned on the basis of VESCF-MO calculations and a partial analysis of the vibronic structure has bees made.

The ultraviolet absorption spectrum of oxalic acid vapor

1984 ◽  
Vol 62 (8) ◽  
pp. 1414-1428 ◽  
Author(s):  
R. A. Back
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Oxalic Acid ◽  
Vibrational Analysis ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
Absorption System ◽  
Acid Vapor ◽  
Medium Resolution ◽  
Partial Analysis

The ultraviolet absorption spectrum of oxalic acid vapor has been studied for the first time. Low-resolution spectra show a moderately weak (εmax = 25 M−1 cm−1 at 277 nm) banded absorption system beginning at about 310 nm and extending to 250 nm where a stronger absorption begins. Medium-resolution spectra show a complex vibrational fine-structure at wavelengths above about 287 nm, with many sharp line-like R-branch heads, each corresponding to a different vibrational transition. A vibrational analysis was completed for 12C2O4H2, 12C2O4D2, and 13C2O4H2, and electronic origins were estimated to be at 31903.2, 31970.2, and 31949.4 cm−1, respectively (about 313 nm). Strong features were assigned to progressions in [Formula: see text] the C=O and C—O stretching vibrations, with prominent sequences in ν10, the C—C torsional vibration, running to the blue, implying that [Formula: see text].This absorption system has been assigned to the first excited singlet state, designated Ã, corresponding to a π* ← n+, 1Au ← 1Ag transition of planar trans-oxalic acid. High-resolution spectra of several bands show rotational fine-structure, and a partial analysis was carried out on the [Formula: see text], and [Formula: see text] bands of 12C2O4H2, based on apparently-simple diverging P-branches.

The ultraviolet absorption spectrum of HCNO in the gas phase

1972 ◽  
Vol 43 (3) ◽  
pp. 467-471 ◽  
Author(s):  
W.David Sheasley ◽  
C.Weldon Mathews
Keyword(s):  
Absorption Spectrum ◽  
Gas Phase ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum

Vibrational Structure of the High-Resolution UV Absorption Spectrum of Acetophenone in the Gas Phase

2021 ◽  
Vol 95 (10) ◽  
pp. 2090-2095
Author(s):  
L. A. Koroleva ◽  
K. S. Andriasov ◽  
A. V. Koroleva
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Gas Phase ◽  
Vibrational Structure ◽  
Uv Absorption ◽  
Uv Absorption Spectrum

Direct Transition Exciton and Fine Structure of the Magneto-Absorption Spectrum in Germanium

1958 ◽  
Vol 109 (6) ◽  
pp. 2207-2209 ◽  
Author(s):  
Solomon Zwerdling ◽  
Laura M. Roth ◽  
Benjamin Lax
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Direct Transition

The molecular structure of methyl(vinyl)-N-nitroamine reinvestigated by gas phase electron diffraction and ab initio MO calculations

1997 ◽  
Vol 413-414 ◽  
pp. 521-525 ◽  
Author(s):  
Igor F. Shishkov ◽  
Lev V. Vilkov ◽  
Lyudmila V. Khristenko ◽  
Per N. Skancke
Keyword(s):  
Molecular Structure ◽  
Electron Diffraction ◽  
Ab Initio ◽  
Gas Phase ◽  
Mo Calculations ◽  
Methyl Vinyl ◽  
Ab Initio Mo Calculations ◽  
Ab Initio Mo ◽  
Gas Phase Electron Diffraction

X-Ray Absorption Fine Structure Study in FeTiO3

1997 ◽  
Vol 11 (16n17) ◽  
pp. 745-748 ◽  
Author(s):  
Rebekah Min-Fang Hsu ◽  
Kai-Jan Lin ◽  
Cheng Tien ◽  
Lin-Yan Jang
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Mixed Valence ◽  
Structure Study ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Trivalent State ◽  
X Ray Absorption

X-ray absorption fine structure XAFS spectroscopy has been used to determine the valence system for the Fe atom in ilmenite, FeTiO3 . This is the first XAFS data in FeTiO3 to our knowledge. The α- Fe2O3 data served as the standard in determining the ionization of the Fe atom in FeTiO3 . Observation of intensity and k-space are consistent. There was no evidence of mixed valence on comparing the FeTiO3 near edge X-ray absorption spectrum with α- Fe2O3 data. The absorption spectra suggest that iron is in the trivalent state in ilmenite.

STUDIES ON NUCLEOPHILIC SUBSTITUTION REACTIONS AT CARBON (SN2(C)) AND SILICON (SN2(Si)) IN TERMS OF AB INITIO, POTENTIAL, ACTING ON AN ELECTRON IN A MOLECULE AND MOLECULAR FACE THEORY

2009 ◽  
Vol 08 (supp01) ◽  
pp. 983-1001 ◽  
Author(s):  
YAN-LI DING ◽  
LI-DONG GONG ◽  
DONG-XIA ZHAO ◽  
MING-BO ZHANG ◽  
ZHONG-ZHI YANG
Keyword(s):  
Ab Initio ◽  
Nucleophilic Substitution ◽  
Gas Phase ◽  
Chemical Bond ◽  
Energy Transition ◽  
High Energy ◽  
Ab Initio Method ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
High Energy Transition

The gas-phase identity bimolecular nucleophilic substitution reactions, Cl- + CH3 Cl → ClCH3 + Cl- and Cl- + SiH3Cl → ClSiH3 + Cl- , are investigated in terms of the ab initio method, potential acting on an electron in a molecule (PAEM) and molecular face (MF) theory. The computations have been performed at the CCSD(T)/aug-cc-pVTZ//MP2/6-311+G(3df,3pd) and CISD/aug-cc-pVDZ level. Based on the ab initio calculation, according to the PAEM theory, the strength of a chemical bond during forming or rupturing may be characterized by the D pb , which is a new physical quantity relating to the barrier height of the PAEM along a chemical bond. According to the MF theory, the interesting pictures of electron transfer and interpolarization effect between the reactants are clearly demonstrated to provide visualized spatial changing features of the MF for the title reactions along the IRC routes. The reason why [ Cl⋯CH3⋯Cl]- is a high-energy transition state is also analyzed in comparison with the stable low-energy intermediate [ Cl⋯SiH3⋯Cl]- .

Vibrational Structure of a High-Resolution UV Absorption Spectrum of 2-Fluoroacryloyl Fluoride in the Gas Phase

2021 ◽  
Vol 76 (6) ◽  
pp. 370-379
Author(s):  
L. A. Koroleva ◽  
K. S. Andriasov ◽  
A. V. Koroleva
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Gas Phase ◽  
Vibrational Structure ◽  
Uv Absorption ◽  
Uv Absorption Spectrum

Gas-phase synthesis of single crystals of Ge–Si system

2020 ◽  
Vol 34 (19) ◽  
pp. 2050178
Author(s):  
Aynur I. Hashimova
Keyword(s):  
Temperature Gradient ◽  
Single Crystals ◽  
Gas Phase ◽  
Vapor Phase ◽  
Solid Solutions ◽  
Closed Volume ◽  
Phase Synthesis ◽  
Polycrystalline Layer ◽  
Cold Zone ◽  
Hot Zone

In this study, the synthesis of single crystals of solid solutions Ge[Formula: see text]Si[Formula: see text] from the gas phase was performed in two different variants. Here, the vapor phase is created in a closed volume. A special ampoule has been made for this purpose. Ge–Si is placed near one end of the ampoule. A temperature gradient is created along the ampoule. The temperature of the hot zone was chosen to be [Formula: see text]C and the temperature of the cold zone to be [Formula: see text]C. It has been found that single crystals can form not only on the polycrystalline layer, but also from separate centers on the walls of the ampoule.

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