Quantitative infrared and near-infrared gas-phase spectra for pyridine: Absolute intensities and vibrational assignments

2018 ◽  
Vol 206 ◽  
pp. 355-366 ◽  
Author(s):  
T.J. Johnson ◽  
P.M. Aker ◽  
N.K. Scharko ◽  
S.D. Williams
Keyword(s):  
Gas Phase ◽  
Near Infrared ◽  
Vibrational Assignments ◽  
Absolute Intensities ◽  
Phase Spectra

scholarly journals The quantitative infrared and NIR spectrum of CH<sub>2</sub>I<sub>2</sub> vapor: vibrational assignments and potential for atmospheric monitoring

2006 ◽  
Vol 6 (1) ◽  
pp. 1275-1299
Author(s):  
T. J. Johnson ◽  
T. Masiello ◽  
S. W. Sharpe
Keyword(s):  
Gas Phase ◽  
Near Infrared ◽  
Point Group ◽  
Aerosol Formation ◽  
Atmospheric Monitoring ◽  
Vibrational Assignments ◽  
Quantitative Absorption ◽  
First Time ◽  
Phase Spectra ◽  
Ft Raman

Abstract. Diiodomethane (CH2I2) photolysis in the presence of ozone is a suggested precursor to new particle aerosol formation, particularly in coastal areas. As part of the PNNL database of gas-phase infrared spectra, the quantitative absorption spectrum of CH2I2 has been acquired at 0.1 cm−1 resolution. Two strong b2 symmetry A-type bands at 584 and 1114 cm−1 are observed, but are not resolved at 760 Torr and appear as B-type. In contrast, the b1 symmetry C-type bands near 5953, 4426 and 3073 cm−1 are resolved with rotational structure, including Q-branches with widths ≤1 cm−1. The quantitative infrared and near-infrared vapor-phase spectra (600–10 000 cm−1) are reported for the first time and discussed in terms of atmospheric monitoring. FT-Raman spectra and ab initio calculations are used to complete vibrational assignments in the C2v point group.

scholarly journals The quantitative infrared and NIR spectrum of CH<sub>2</sub>I<sub>2</sub> vapor: vibrational assignments and potential for atmospheric monitoring

2006 ◽  
Vol 6 (9) ◽  
pp. 2581-2591 ◽  
Author(s):  
T. J. Johnson ◽  
T. Masiello ◽  
S. W. Sharpe
Keyword(s):  
Absorption Spectrum ◽  
Gas Phase ◽  
Near Infrared ◽  
Point Group ◽  
Atmospheric Monitoring ◽  
Vibrational Assignments ◽  
Quantitative Absorption ◽  
First Time ◽  
Phase Spectra ◽  
Ft Raman

Abstract. Diiodomethane (CH2I2) has recently become a molecule of significant atmospheric interest as it can contribute to coastal IO formation. As part of the PNNL database of gas-phase infrared spectra, the quantitative absorption spectrum of CH2I2 has been acquired at 0.1 cm-1 resolution. Two strong b2 symmetry A-type bands at 584 and 1114 cm-1 are observed, but are not resolved when broadened to 760 Torr with nitrogen and appear as B-type. In contrast, the b1 symmetry C-type bands near 5953, 4426 and 3073 cm-1 are resolved with rotational structure, including Q-branches with widths ≤1 cm-1. The quantitative infrared and near-infrared vapor-phase spectra (600–10 000 cm-1) are reported for the first time. Some bands are discussed in terms of their potential for atmospheric monitoring and theoretical detection limits on a selected basis. FT-Raman spectra and ab initio calculations are used to complete vibrational assignments in the C2v point group.

FT-IR Photoacoustic Spectra of Gaseous Group VIB Metal Chalcocarbonyl Complexes

1986 ◽  
Vol 40 (7) ◽  
pp. 1004-1009 ◽  
Author(s):  
Zhen H. Xu ◽  
Ian S. Butler ◽  
Francois G. T. St.-Germain
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Vibrational Assignments ◽  
Photoacoustic Spectra ◽  
Excellent Quality ◽  
Ft Ir ◽  
Phase Spectra ◽  
Solid Complexes

Attempts to record the room-temperature, FT-IR photoacoustic (PA) spectra of the crystalline group VIB metal chalcocarbonyls, M(CO)6 (M = Cr, Mo, W) and Cr(CO)5(CS), suprisingly failed owing to the high volatilities of the solid complexes in the PA cell, and excellent-quality gas-phase spectra were obtained instead. Vibrational assignments are proposed for these gases for the CO stretching and MCO bending fundamentals, and the associated binary overtone and combination spectra in the 4500–500 cm−1 region. The binary overtone and combination spectra are easily observed in the FT-IR/PA spectra and are useful in distinguishing between the four metal chalcocarbonyl complexes.

Infrared Photoacoustic Spectra of Gaseous Pentacarbonyl(Methyl)Manganese(I) and Pentacarbonyl(Methyl)Rhenium(I)

1992 ◽  
Vol 46 (11) ◽  
pp. 1605-1607 ◽  
Author(s):  
Ian S. Butler ◽  
Denis F. R. Gilson ◽  
Dominique Lafleur
Keyword(s):  
Gas Phase ◽  
Carbonyl Complexes ◽  
Volatile Solid ◽  
Local Surface ◽  
Vibrational Assignments ◽  
Photoacoustic Spectra ◽  
Near Ir ◽  
Heating Effects ◽  
Nondestructive Identification ◽  
Phase Spectra

Gas-phase IR photoacoustic (PA) spectra have been obtained for the volatile, solid pentacarbonyl(methyl)metal(I) complexes, CH3Mn(CO)5 and CH3Re(CO)5. The gaseous samples were apparently produced directly in the PA sample cup as the result of local surface heating effects. Vibrational assignments are given for the gas-phase spectra, especially for the binary v(CO) overtone and combinations which absorb in the near-IR region at ∼4000 cm−1. The data provide further support for near-IR/PA spectroscopy being a useful technique for the rapid, nondestructive identification of small amounts of organometallic carbonyl complexes.

Interaction of the C = N Bond with the Cyclopropyl Ring

1981 ◽  
Vol 36 (7) ◽  
pp. 768-773 ◽  
Author(s):  
Shatha F. Al-Siaidi ◽  
Ibrahim T. Ibrahim ◽  
Keyword(s):  
Excited State ◽  
Nitrogen Atom ◽  
Gas Phase ◽  
Bathochromic Shift ◽  
Wave Number ◽  
Phase Spectra

Abstract The conjugative interaction of the C=N bond with the cyclopropylring is studied using UV-spectrophotometric technique. The observed small bathochromic shift in the n-n* bands, relative to the spectra of similar compounds but with no cyclopropylring, is attributed to the interaction of the internal Walsh MO with the nonbonded MO of the Nitrogen atom (Zlint-n interaction) in the bisected conformation of the molecule. The observed bathochromic shifts of the 71-71* bands are explained in terms of the A-n interaction. The gas phase spectra of the azomethine derivatives show vibronic structuring of the band which when analyzed yeld wave number differences be­ tween the successive vibronic peaks, of the magnitude 720—860 cm-1. They are attributed to to the wave number differences between the successive C—N=C deformed ion levels in the excited state. I n te r a c tio n o f th e C = N B o n d w ith th e C y c lo p r o p y l R in g

An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues

2016 ◽  
Vol 18 (15) ◽  
pp. 10207-10217 ◽  
Author(s):  
Ivan Ljubić ◽  
Antti Kivimäki ◽  
Marcello Coreno
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Excitation Spectra ◽  
Core Excitation ◽  
The Core ◽  
Nitroxide Free Radical ◽  
Phase Spectra ◽  
Stable Nitroxide

Core excitation (NEXAFS) C 1s, N 1s, and O 1s gas-phase spectra of stable nitroxide free radical TEMPO and two of its amide-substituted analogues are assigned from the onset of the absorptions to the vicinity of the core-ionization thresholds using the theoretical TDDFT and ΔDFT methods.

Anharmonic Vibrational Analysis of the Infrared and Raman Gas-Phase Spectra of s-trans- and s-gauche-1,3-Butadiene

2015 ◽  
Vol 119 (43) ◽  
pp. 10706-10723 ◽  
Author(s):  
Sergey V. Krasnoshchekov ◽  
Norman C. Craig ◽  
Praveenkumar Boopalachandran ◽  
Jaan Laane ◽  
Nikolay F. Stepanov
Keyword(s):  
Gas Phase ◽  
Vibrational Analysis ◽  
Phase Spectra

Electronic Gas-Phase Spectra of Larger Polyacetylene Cations

2007 ◽  
Vol 111 (10) ◽  
pp. 1887-1890 ◽  
Author(s):  
Anatoly Dzhonson ◽  
Evan B. Jochnowitz ◽  
John P. Maier
Keyword(s):  
Gas Phase ◽  
Phase Spectra

Etude à basse température dans l'infrarouge proche du dimère (NO)2

1984 ◽  
Vol 62 (4) ◽  
pp. 322-329 ◽  
Author(s):  
V. Menoux ◽  
R. Le Doucen ◽  
C. Haeusler ◽  
J. C. Deroche
Keyword(s):  
Excited State ◽  
Gas Phase ◽  
Ground State ◽  
Near Infrared ◽  
Heat Of Formation ◽  
Wave Number ◽  
Vibrational Modes ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Absorption Intensity

The spectrum of the dimer (NO)2 in the gas phase has been studied in the near infrared at temperatures between 118 and 138 K. More specifically, the measure of absorption intensity of the ν4 and ν1 + ν4 bands has yielded the heat of formation of the dimer, −2.25 kcal/mol at 128 K, and revealed the influence of the low vibrational modes on this measure. The observation of the ν4 – ν6, difference band has yielded the wave number value of the ν6, fundamental band, forbidden in the infrared. The rotational constants of the vibrationally excited state were found to be larger than the ground state rotational constants, this result being very unusual.

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