Laser-induced fluorescence excitation spectroscopy of N2 + produced by VUV photoionization of N2 and N2O

1998 ◽  
Vol 5 (3) ◽  
pp. 1069-1071 ◽  
Author(s):  
Masakazu Mizutani ◽  
Hiromichi Niikura ◽  
Atsunari Hiraya ◽  
Koichiro Mitsuke
Keyword(s):  
Second Harmonic ◽  
Rotational Temperature ◽  
Wavelength Region ◽  
Grazing Incidence ◽  
Spectral Width ◽  
Laser Induced Fluorescence ◽  
Laser Wavelength ◽  
Excitation Spectra ◽  
Fluorescence Excitation ◽  
Vuv Photoionization

Synchrotron radiation emitted from the UVSOR storage ring is monochromated by a grazing-incidence monochromator and introduced coaxially with the second harmonic of a mode-locked Ti:sapphire laser. Sample gases, N2 and N2O, are photoionized into vibronically ground N2 + with the fundamental light of the undulator radiation at 18.0 and 18.6 eV, respectively. Laser-induced fluorescence (LIF) excitation spectra of N2 + from N2 and N2O are measured in the laser wavelength region of the (B 2Σ u +, v′ = 0) ← (X 2Σg +, v′′ = 0) transition at 389–392 nm. The LIF excitation spectra of N2 + exhibit two maxima due to the P and R branches in which rotational bands are heavily overlapped. The rotational temperature is determined by simulating an LIF excitation spectrum by using the theoretical intensity distribution of rotation bands convoluted with the spectral width of the laser.

Laser-Induced Fluorescence Excitation Spectra oftert-Butoxy and 2-Butoxy Radicals

1999 ◽  
Vol 103 (41) ◽  
pp. 8207-8212 ◽  
Author(s):  
Chuji Wang ◽  
Liat G. Shemesh ◽  
Wei Deng ◽  
Michael D. Lilien ◽  
Theodore S. Dibble
Keyword(s):  
Laser Induced Fluorescence ◽  
Excitation Spectra ◽  
Fluorescence Excitation ◽  
Fluorescence Excitation Spectra

The rotationally resolved electronic spectra of several conformers of 1-hexoxy and 1-heptoxy

2004 ◽  
Vol 82 (6) ◽  
pp. 854-866 ◽  
Author(s):  
Lily Zu ◽  
Jinjun Liu ◽  
Sandhya Gopalakrishnan ◽  
Terry A Miller
Keyword(s):  
Atmospheric Chemistry ◽  
Electronic Spectroscopy ◽  
Laser Induced Fluorescence ◽  
Organic Radicals ◽  
Excitation Spectra ◽  
Fluorescence Excitation ◽  
Alkoxy Radicals ◽  
Fluorescence Excitation Spectra ◽  
Quantum Chemistry Calculations ◽  
Experimental Values

Laser-induced fluorescence excitation spectra of five vibronic bands of 1-hexoxy and three bands of 1-heptoxy have been recorded in a jet-cooled environment. Experimental values of rotational constants for both the [Formula: see text] and [Formula: see text] states and components of the spin-rotational tensor for the [Formula: see text] state were obtained by an analysis of the partially resolved rotational structure of the vibronic bands. Comparing these experimental results with quantum chemistry calculations, and using corresponding assignments of smaller alkoxy radicals as a guide, permitted unambiguous conformational assignments for the bands. The extension of similar assignments to larger alkoxy radicals is also discussed. Key words: electronic spectroscopy, organic radicals, combustion, atmospheric chemistry.

scholarly journals Aggregation of cation-anionic and related polymethine dyes

2000 ◽  
Vol 2 (1) ◽  
pp. 17-21 ◽  
Author(s):  
A. S. Tatikolov ◽  
G. Ponterini ◽  
Zh. A. Krasnaya
Keyword(s):  
Absorption Spectra ◽  
Ion Pairs ◽  
Wavelength Region ◽  
Polymethine Dyes ◽  
Gradual Transition ◽  
Solvent Mixtures ◽  
Anionic Dyes ◽  
Excitation Spectra ◽  
Absorption Bands ◽  
Fluorescence Excitation

Absorption, fluorescence, and fluorescence excitation spectra were studied for a number of cation-anionic and related anionic polymethine dyes in weakly polarand nonpolarsolvents, as well as in binary mixtures of solvents of different polarity. For some dyes, aggregation is observed in toluene or acetonitrile-toluene mixtures with low amounts of acetonitrile, which is revealed as appearance of new absorption bands and/or broadening of the initial bands of a monomeric dye. Solvent mixtures butyronitrilehexane with low butyronitrile content were found to greatly stimulate the formation of dye aggregates for most of the dyes studied. The absorption spectra of the aggregates are often blue-shifted with respect to the corresponding absorption spectra of parent monomeric dyes and/or represent broad continuums located both in the blue and red regions. For one of the cation-anionic dyes studied, which consists of3,3′-diethylthiamonomethinecyanine cation and trimethinebenzoxanine anion, fluorescent aggregates were observed; their broad fluorescence band is located in the long-wavelength region. For this dye, gradual transition from nonfluorescent aggregates to fluorescent ones and then to monomeric ion pairs and dissociated ions was observed in butyronitrile-hexane mixtures with growing butyronitrile content.

Laser-induced fluorescence and discharge emission spectra of CrO. Rotational analysis of the A5Π–X5Π transition

1980 ◽  
Vol 58 (4) ◽  
pp. 516-533 ◽  
Author(s):  
W. H. Hocking ◽  
A. J. Merer ◽  
D. J. Milton ◽  
W. E. Jones ◽  
G. Krishnamurty
Keyword(s):  
Fluorescence Spectra ◽  
Rotational Temperature ◽  
Electronic States ◽  
Emission Spectra ◽  
Laser Induced Fluorescence ◽  
Spin Orbit Coupling ◽  
Excitation Spectra ◽  
Large Numbers ◽  
Parallel Polarization ◽  
Indirect Information

The A5Π–X5Π electronic transition of CrO, near 6000 Å, has been analysed in detail using laser-induced fluorescence and conventional discharge emission spectroscopy. The transition provides the first instance where it has been possible to analyse the rotational structures of quintet electronic states completely. Although the parallel polarization of the transition has prevented the spin–orbit coupling and Λ-doubling intervals from being observed directly, it is shown that sufficient indirect information exists in the spectrum for them to be obtained with fair precision. The excited state, A5Π, is perturbed by large numbers of other electronic states which have no intensity of their own for emission to the ground state. The analysis of the perturbed regions has been greatly facilitated by the laser-induced fluorescence spectra: the excitation spectra correspond to a rotational temperature close to room temperature (which offers a significant improvement in resolution over the discharge spectra), and the J-assignments of the perturbed lines given by the resolved fluorescence spectra are unambigious

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