Critical assessment: Use of supersonic jet spectrometry for complex mixture analysis (IUPAC Technical Report)

2003 ◽  
Vol 75 (7) ◽  
pp. 975-998 ◽  
Author(s):  
Totaro Imasaka ◽  
D. S. Moore ◽  
T. Vo-Dinh
Keyword(s):  
Electronic State ◽  
Vibrational Level ◽  
Excited Electronic State ◽  
Supersonic Jet ◽  
Complex Mixture ◽  
Chemical Species ◽  
Basic Research ◽  
Analytical Technique ◽  
Detection Techniques ◽  
Supersonic Jet Expansion

When cooled to a temperature of a few K using supersonic jet expansion into a vacuum, a molecule exists in the lowest vibrational level of the ground electronic state and is isolated at collision-free conditions. The absorption or excitation/fluorescence spectrum is then greatly simplified, when transitions occur from this single vibrational level to a limited number of vibrational levels in the excited electronic state. This method, called supersonic jet spectrometry, is a powerful analytical technique because of its high selectivity, since the chemical species can be accurately identified and selectively quantified using the sharp spectral features even for large molecules. Supersonic jet spectrometry has distinct advantages over other low-temperature spectrometries,in that it can be combined with gas-phase separation and detection techniques such as chromatography or mass spectrometry. Therefore, this spectrometric technique can be used as a versatile analytical means, not only for basic research on pure substances, but also for practical trace analysis of chemical species in multicomponent samples (e.g., in biological monitoring or in environmental monitoring).

Supersonic jet spectrometry of chemical species resulting from thermal decomposition of polystyrene and polycarbonate

1992 ◽  
Vol 64 (19) ◽  
pp. 931A-940A ◽  
Author(s):  
Totaro Imasaka ◽  
Masami Hozumi ◽  
Nobuhiko Ishibashi
Keyword(s):  
Thermal Decomposition ◽  
Supersonic Jet ◽  
Chemical Species

Variational Method for Estimating the Dipole Moment in the Second Excited State of Fluorescein Molecule from its Electronic UV Absorption Spectra

2019 ◽  
Vol 70 (10) ◽  
pp. 3538-3544
Author(s):  
Alina Costina Luca ◽  
Ana Cezarina Morosanu ◽  
Irina Macovei ◽  
Dan Gheorghe Dimitriu ◽  
Dana Ortansa Dorohoi ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Variational Method ◽  
Electronic State ◽  
Excited Electronic State ◽  
Spectral Band ◽  
Uv Absorption ◽  
Optical Parameters ◽  
Electrical Permittivity ◽  
Fluorescein Molecule

Electro-optical parameters of fluorescein molecule in the second excited electronic state and information on the interactions with solvents were obtained from a solvatochromic study. Parameters of the solvents such as the refractive index, electrical permittivity and Kamlet-Taft parameters (hydrogen bond acidity and basicity) were related with the experimentally recorded shifts of UV absorption spectral band of fluorescein dissolved in several solvents. Through a variational method, the electric dipole moment and polarizability in excited state of fluorescein molecule were estimated. The calculus requires some parameters of the fluorescein molecule in the ground electronic state, which were determined through a quantum-mechanical study.

scholarly journals The flame spectrum of carbon monoxide

1940 ◽  
Vol 176 (967) ◽  
pp. 505-521 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Electronic State ◽  
Excited Electronic State ◽  
Combustion Process ◽  
Wave Number ◽  
Band Spectrum ◽  
Liquid Form ◽  
Triangular Form ◽  
Reduced Pressure

The spectrum of the flame of carbon monoxide burning in air and in oxygen at reduced pressure has been photographed on plates of high contrast which display the band spectrum clearly above the continuous background. Greater detail has been obtained than has been recorded previously and new measurements are given. The structure of the spectrum has been studied systematically. It is shown that the bands occur in pairs with a separation of about 60 cm. -1 , this separation being due probably to the rotational structure. Various wave-number differences are found to occur frequently, and many of the strong bands are arranged in arrays using intervals of 565 and 2065 cm. -1 . The possible origin of the spectrum is discussed. The choice of emitter is limited to a polyatomic oxide of carbon, of which carbon dioxide is the most likely. The spectrum of the suboxide C 3 O 2 shows some resemblance to the flame bands, but this molecule is improbable as the emitter on other grounds. A peroxide C0 3 is also a possibility, but no evidence for the presence of this has been obtained from experiments on the slow combustion of carbon monoxide. Carbon dioxide in gaseous or liquid form is transparent through the visible and quartz ultra-violet, and the flame bands are not obtained from CO 2 in discharge tubes. Comparison with the Schumann-Runge bands of oxygen shows that it is possible that the flame bands may form part of the absorption band system of CO 2 which is known to exist below 1700 A if there is a big change in shape or size of the molecule in the two electronic states. The electronic energy levels of CO 2 are discussed. Since normal CO 2 is not built up from normal CO and oxygen, an electronic rearrangement of the CO 2 must occur after the combustion process. Mulliken has suggested that the molecule in the first excited electronic state, corresponding to absorption below 1700 A, may have a triangular form. The frequencies obtained from the flame bands are compared with the infra-red frequencies of CO 2 . The 565 interval may be identified with the transverse vibration v 2 , indicating that the excited electronic state is probably triangular in shape. The 2065 interval cannot, however, be identified with the asymmetric vibration v 3 with any certainty. If the excited electronic state of CO 2 is triangular, then molecules formed during the combustion by transitions from this level to the ground state may be “vibrationally activated”. This is probably the reason for many of the peculiarities of the combustion of carbon monoxide.

Vibrational Raman scattering in an optical pumped excited electronic state

1979 ◽  
Vol 65 (2) ◽  
pp. 293-295 ◽  
Author(s):  
M. Asano ◽  
D. Mongeau ◽  
D. Nicollin ◽  
R. Sasseville ◽  
J.A. Koningstein
Keyword(s):  
Raman Scattering ◽  
Electronic State ◽  
Excited Electronic State

A New Liquid Droplet Laser Desorption Source Combined with Supersonic Jet Expansion: Application to Phenol and its Water Clusters

2014 ◽  
Vol 228 (4-5) ◽  
Author(s):  
Chayan Kanti Nandi ◽  
Hans-Dieter Barth ◽  
Bernhard Brutschy
Keyword(s):  
Gas Phase ◽  
Water Clusters ◽  
Liquid Droplet ◽  
Supersonic Jet ◽  
Laser Desorption ◽  
Laser Source ◽  
Published Data ◽  
Two Photon ◽  
Supersonic Jet Expansion ◽  
Phase Out

AbstractWe have developed a new laser source, for the spectroscopy of nonvolatile molecules in gas phase. It is based on a laser induced liquid bead ion desorption source (LILBID) combined with a supersonic beam. The cold molecules produced with this technique are sampled with Resonant Two Photon Ionization spectroscopy (R2PI) to measurement of the gas phase optical spectra. LILBID allows to bring nonvolatile molecule from liquid phase (out of a droplet) into gas phase, by means of multi photon ablation with IR photons exciting the vibrations of the solvent. Phenol and its different water clusters have been used as an example to demonstrate the method and to standardise the new experimental setup. The recorded R2PI spectral data of phenol monomer and its different water clusters obtained from this laser desorption technique are in very good agreement with the previously published data. This technique opens a new door for the measurement of molecules under microsolvation and potentially for

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