Laser fluorescence and high vibrational levels of 15NO2

1979 ◽  
Vol 57 (6) ◽  
pp. 828-835 ◽  
Author(s):  
J. C. D. Brand ◽  
P.-H. Chiu ◽  
A. R. Hoy
Keyword(s):  
Magnetic Resonance ◽  
Ground State ◽  
Narrow Band ◽  
Laser Fluorescence ◽  
Resonance Fluorescence ◽  
Infrared Measurements ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Laser Magnetic Resonance ◽  
Electronic Ground

Resonance fluorescence of 15NO2 excited by narrow-band radiation of an Ar+ laser at 514, 495, 488, and 476 nm is reported and analyzed. The data are combined with published laser magnetic resonance and infrared measurements to obtain a set of vibration and vibration–rotation constants for the electronic ground state of this isotope.The fluorescence bands reported are a-axis polarized, corresponding to a transition moment [Formula: see text] between 2B2 and 2A1 basis states. Numerous anomalies in the vibrational and rotational structure of the fluorescence indicate that, in the region of the manifold probed by the laser, vibrational levels of the parent 2B2 basis state mix extensively with one another as well as with high vibrational levels of the 2A1 ground state.

Laser-excited fluorescence of 15NO2 and N18O2

1976 ◽  
Vol 54 (10) ◽  
pp. 1069-1076 ◽  
Author(s):  
J. C. D. Brand ◽  
J. L. Hardwick ◽  
K. E. Teo
Keyword(s):  
Ground State ◽  
Selection Rule ◽  
Vibrational Energy ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Resonance Fluorescence ◽  
Vibrationally Excited ◽  
Vibrational Levels ◽  
Vibrational Constants ◽  
Electronic Ground

Measurements are reported of the resonance fluorescence of 15N16O2 and 14N18O2 excited by the 488,496, and 514 nm radiation of an Ar+ laser. The frequency displacements in these spectra are consistent with values calculated previously, using potential constants for the electronic ground state of NO2 derived from the rotational and vibrational constants of NO2 and 15N16O2 but containing no information from N18O2 spectra; the agreement obtained for the latter isotope is therefore a partial test of the potential field.In these spectra, fluorescence occurs from vibronic B2 levels of the Ã2B2 state possessing 7500–8500 cm−1 of vibrational energy. A number of examples are described in which the emission from these vibrationally excited levels shows an anomalous intensity distribution or K-selection rule (e.g., ΔK = ±2) as a result of Coriolis and/or spin–orbit coupling between vibrational levels of the upper electronic state.

A determination of the molecular parameters for NiH in its 2Δ ground state by laser magnetic resonance

1991 ◽  
Vol 148 (2) ◽  
pp. 462-478 ◽  
Author(s):  
Thomas Nelis ◽  
Stuart P. Beaton ◽  
Kenneth M. Evenson ◽  
John M. Brown
Keyword(s):  
Magnetic Resonance ◽  
Ground State ◽  
Molecular Parameters ◽  
Laser Magnetic Resonance

Laser Magnetic Resonance Spectra of 14NO2 and 15NO2 near 1600 cm−1

1975 ◽  
Vol 53 (19) ◽  
pp. 1929-1938 ◽  
Author(s):  
S. M. Freund ◽  
J. T. Hougen ◽  
W. J. Lafferty
Keyword(s):  
Magnetic Resonance ◽  
Spin Rotation ◽  
Zero Field ◽  
Co Laser ◽  
Wave Numbers ◽  
Vibration Rotation ◽  
Laser Magnetic Resonance ◽  
Stable Molecule ◽  
Transition Wave ◽  
Good Agreement

Two laser magnetic resonance patterns for 14NO2 and six patterns for 15NO2, observed using six CO laser transitions, have been analyzed to yield spin corrected zero-field vibration–rotation transition wave numbers and zero-field spin–rotation splittings. The 14NO2 results are in good agreement with results obtained from conventional infrared grating studies. The 15NO2 results allow new values of ν0 = 1582.107 ± 0.008, A′ − A″ = −0.2116 ± 0.0011, and DK′ − DK″ = −1.39 ± 0.20 × 10−4 cm−1 to be determined for the ν3 fundamental of that molecule (errors are 3 standard deviations). Two spectral figures and a list of assigned Zeeman lines are presented to permit using this stable molecule as an aid in adjusting newly constructed instruments. Closed form approximate intensity expressions are given for Zeeman transitions of the type observed in this work, i.e., for sharp partially spin forbidden Zeeman transitions in A type bands of near prolate asymmetric rotors.

The ultra-violet spectra of HF and DF

1959 ◽  
Vol 251 (1267) ◽  
pp. 504-518 ◽  
Keyword(s):  
Ground State ◽  
Ultra Violet ◽  
Electric Discharges ◽  
Excited Singlet ◽  
Potential Minimum ◽  
Large Numbers ◽  
Vibrational Levels ◽  
Theoretical Predictions ◽  
Vibration Rotation ◽  
Available Information

Successful analyses have been m ade of th e ultra-violet spectra excited by electric discharges in m ixtures of helium with HF or DF. The spectra, which consist of large numbers of irregularly spaced lines, are shown to arise from transitions V 1 Σ + - X 1 Σ + in neutral HF and DF. State X is the ground state: state V , the lowest stable excited singlet state, probably correlates with H + + F - . The potential minimum of state V lies at 10·5 eV above that of the ground state. The internuclear distance in this state —in agreement with theoretical predictions — is large, more than twice that in the ground state, so that the bands observed consist of transitions from low vibrational levels in V to high vibrational levels in X . In HF, the observed levels are 9 ≤ v " ≤ 19: predissociation by rotation is observed in the levels 10 ≤ v " ≤ 19. The last vibrational state which may have a few stable rotational levels is v " = 20, so that, by combining the present observations with those of the vibration-rotation bands, there is now available information about the vibrational and rotational levels over the greater part of their range of stable existence in the ground state. The dissociation energy, D" 0 , of HF is found to be 5·86 ±0·01 eV.

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