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1.
The emission spectra of the 0-2, 4-2, and 6-1 bands of the Comet-Tail (A2Πi − X2Σ+) system in the 14C16O+ isotopic molecule, comprising nearly 600 lines, have been recorded and analyzed for the first time. The spectra have been photographed under high resolution by using conventional spectroscopy, and it was possible to separate and observe most of the lines of all the 12 branches of this transition. The reduction of the individual bands’ spectra has been performed by nonlinear least-squares procedure and by means of effective Hamiltonians of Brown et al. the rovibronic structure parameters have been obtained. The currently investigated bands of the Comet-Tail system and the earlier analyzed bands of the A − X and B − A systems in the 14C16O+ molecule have been merged together. The results of this global fit made it possible to derive a new set of the equilibrium molecular constants for the A and X states. Then the RKR potential curve parameters for both A and X states and Franck-Condon factors as well as r-centroids for the A − X transition have been calculated for the 14C16O+ molecule. 相似文献
2.
Emission spectra of the A2Π3/2-X2Σ+ (0, 1), (0, 0), and (1, 0) bands and the B2Σ+-X2Σ+ (0, 1), (0, 0), (1, 0), (2, 0), and (3, 1) bands of ScS have been recorded in the 10 000-13 500 cm−1 region at a resolution of 0.05 cm−1 using a Fourier transform (FT) spectrometer. The A2Πr-X2Σ+ (1, 0) band as well as the B2Σ+-X2Σ+ (0, 0) and (1, 0) bands have been recorded at high resolution (±0.001 cm−1) by laser excitation spectroscopy using a supersonic molecular beam source. The FT spectral features range up to N = 148, while those recorded with the laser cover the “low-N” regions. The lines recorded with the laser exhibit splittings due to the 45Sc (I = 7/2) magnetic hyperfine interactions, which are large (∼6.65 GHz) in the X2Σ+ state and much smaller in the B2Σ+ and A2Π states. The energy levels were modeled using a traditional ‘effective’ Hamiltonian approach, and improved spectroscopic constants were extracted and compared with previous determinations and theoretical predictions. 相似文献
3.
K.D. Setzer 《Journal of Molecular Spectroscopy》2006,236(2):224-233
Emission spectra of the b1Σ+(b0+) → X3Σ−(X10+,X21) and a1Δ(a2) → X21 transitions of AsBr have been measured in the near-infrared spectral region with a Fourier-transform spectrometer. The arsenic bromide radicals were generated in fast-flow systems by reaction of arsenic vapor (Asx) with bromine and were excited by microwave-discharged oxygen. The most prominent features in the spectrum are the Δv = +1,0,−1, and −2 band sequences of the b1Σ+(b0+) → X3Σ−(X10+) transition in the range 11 700-12 700 cm−1. With lower intensities, the Δv = 0 and −1 sequences of the b1Σ+(b0+) → X3Σ−(X21) sub-system show up in the same range. Further to the red, between 6000 and 6700 cm−1, the Δv = 0, +1, and −1 sequences of the hitherto unknown a1Δ(a2) → X21 transition are observed. Analyses of medium- and high-resolution spectra have yielded improved molecular constants for the X10+, X21, and b0+ states and first values of the electronic energy and the vibrational constants of the a2 state. 相似文献
4.
Time-resolved Fourier transform emission spectroscopy of AΠ-XΣ infrared transition of the CN radical
The A2Π-X2Σ+Δv = −3 bands of the 12C14N radical have been observed by time-resolved Fourier transform spectroscopy in the 1850-3100 cm−1 region with a wavenumber resolution of 0.025 cm−1. The radical was produced in a pulsed positive column discharge in a cyanogene and helium mixture. Seven bands of v = 0-3, 1-4, 2-5, 3-6, 4-7, 5-8, and 6-9 were analyzed to give the molecular constants of each state by least-squares fitting of 801 lines. The pulsed discharge was found to be efficient for production of CN in the excited A2Π state. The vibrational excitation temperature was determined to be 6680 ± 835 K and 6757 ± 534 K for the A2Π and X2Σ+ states, respectively. The population of the A2Π was found to be 4% of that of the X2Σ+ state in the time after turning off the discharge. 相似文献
5.
The emission spectra of the A2П-X2Σ+ (red) system of 12C14N have been reinvestigated in the 3500-22 000 cm−1 region at high resolution using a Fourier transform spectrometer. In total, spectra of 63 bands involving vibrational levels up to v′ = 22 of the A2П state and v″ = 12 of the X2Σ+ ground state have been measured and rotationally analyzed providing an improved set of spectroscopic constants. The present measurements of the Δv = −2 sequence bands of 12C14N and those of 13C14N from Ram et al. (2010) [36] allow for a much improved identification of these two isotopologues in the near infrared spectra of carbon stars. 相似文献
6.
Patrice Cacciani 《Journal of Molecular Spectroscopy》2004,225(1):62-65
A tunable and narrowband vacuum ultraviolet laser system near λ=107.5 nm is used to record Doppler-free molecular beam spectra of the E1Π-X1Σ+ (0,0) band for three isotopomers of carbon monoxide. The Q branches of the E-X (0,0) bands in 12C16O, 13C16O, and 13C18O are fully resolved in this study, performed at a resolution of 0.02 cm−1 (FWHM). The newly obtained data are included in a comprehensive fitting routine with previous data to yield optimized molecular constants for the upper level. 相似文献
7.
The absorption spectrum of the 18O enriched carbon dioxide has been recorded at Doppler limited resolution with a Fourier transform spectrometer in the spectral range 3800-8500 cm−1. Seventeen cold bands (14Σ-Σ and 3Σ-Π) and nine hot bands (9Π-Π) of 12C18O2, nineteen cold bands (18Σ-Σ and 1Σ-Π) and eighteen hot bands (6Σ-Σ, 9Π-Π and 3Δ-Δ) of 16O12C18O have been observed. Among them, 14 12C18O2 bands and 12 16O12C18O bands are observed for the first time. The spectroscopic parameters Gv, Bv, and centrifugal distortion constants, have been determined for all observed bands. Effective Hamiltonian parameters for the 12C18O2 isotopic species are retrieved from the global fitting of the observed line positions presented in this paper and collected from the literature. As the result, 65 obtained effective Hamiltonian parameters reproduce 5443 observed line positions of 73 12C18O2 bands with RMS = 0.00145 cm−1. 相似文献
8.
Christopher R. Brazier José I. Ruiz Sylvia V. Parks 《Journal of Molecular Spectroscopy》2007,241(1):1-6
The gas phase spectrum of the silicon boride radical has been observed for the first time. Two electronic transitions were observed in emission from a corona excited supersonic expansion source. The D4Σ−-X4Σ− system consists of emission from v′ = 0 to v″ = 0-3, while the A4Π-X4Σ− system consists of numerous bands with v′ = 0-5 and v″ = 0-11, although only the strong 0-0 and 0-1 bands have been analyzed so far. 相似文献
9.
10.
M.J. Dick 《Journal of Molecular Spectroscopy》2004,227(2):187-194
Several new transitions of holmium monochloride (HoCl) have been studied at high resolution using laser excitation spectroscopy. Two main transitions, B[17.7]8-X8 and C[19.3]9-X8 have been observed and five bands, 0-0, 0-1, 1-0, 1-1, and 2-1 of the B-X transition and three bands, 0-0, 0-1, and 0-3 of the C-X transition have been obtained at high resolution and rotationally analyzed. Among several low lying states observed in dispersed fluorescence was a strong transition from the C state to a state ∼2140 cm−1 above the ground state. Excitation spectra of this transition have shown that there are apparently two states, ∼6 cm−1 apart. Comparison with ligand field theory calculations are consistent with assigning these states to the excited low lying Ho+(4f116s)Cl− configuration. Several other low lying electronic states have been observed in dispersed fluorescence spectra. Although their assignments could not be established, their energies suggest that they are from the Ho+(4f106s2)Cl− or Ho+(4f116s)Cl− configurations. Rotational constants have been obtained for the B[17.7]8 and C[19.3]9 states and have been used to speculate on the possible electron configurations for these states. 相似文献
11.
Spectroscopic observations are reported for rhodium monoxide from hollow-cathode emission and laser-induced fluorescence experiments. Eleven bands of Rh16O and 10 of Rh18O, from the [15.8]2Π-X4Σ− (b) and [16.0]2Π-X4Σ− (b) transitions, have been rotationally analyzed. The ground state constants have been determined as B0 = 0.4132, λ0 = −0.58 and γ0 = −0.102, in cm−1. Rotational and lambda doubling parameters in v = 0, 1, 2, and 3 excited state vibrational levels have also been determined. 相似文献
12.
The spectrum of B2Σ+-X2Σ+ system of AlO has been recorded on BOMEM DA8 Fourier transform spectrometer at an apodized resolution of 0.05 cm−1. Nineteen bands of the Δv = 1, 0, −1, and −2 sequences of this band system have been analyzed for the rotational structure. Out of which seven bands, viz. 3-2, 4-3, 2-3, 3-4, 4-5, 5-6 and 6-7 have been analyzed for the first time. The rotational lines of these 19 bands along with 20 earlier analyzed bands, a total of 7200 lines, have been fitted in a simultaneous least squares fit. The study has resulted in determining more precise vibrational and rotational constants of the two states. Because of the high resolution employed it became necessary to invoke H0 and H1 coefficients, and a fifth order term to explain the anomalous spin-doubling observed in the v″ = 5, 6 and 7 levels of the X2Σ+ state. 相似文献
13.
Christof Maul Mikhail Poretskiy Jörg Grunenberg 《Journal of Molecular Spectroscopy》2009,256(1):80-85
The possibility of simultaneous characterization of N2O and N2O van der Waals complexes in supersonic jet expansions is demonstrated for neat N2O samples. Room temperature and jet-cooled spectra of the Rydberg transitions 3pπ1Δ ←← X1Σ+ and 3pσ1Π ←← X1Σ+ are presented. Theoretical calculations support the assignment of the Rydberg transitions used. For stagnation pressures above 2 bar, a hitherto unreported broad spectral feature at 84 650 cm−1 is observed, where calculations predict absorption of the (N2O)2 dimer essentially due to excitation of the 4sσ and 3pπ Rydberg orbitals. Consequences for the use of N2O as a precursor for O(1D) atoms in reactive scattering experiments are discussed. 相似文献
14.
K.D. Setzer 《Journal of Molecular Spectroscopy》2003,221(1):19-22
Emission spectra of the b1Σ+(b0+)→X3Σ−(X10+) transition of phosphorus iodide have been measured with a high-resolution Fourier-transform spectrometer. The PI radicals were generated and excited in a fast-flow system by reaction of phosphorus vapor (Px) with iodine and microwave-discharged oxygen. Four sequences, Δv=0,+1,−1,−2, of the b1Σ+(b0+)→X3Σ−(X10+) transition of PI comprising 28 bands were observed. Six bands were measured at high spectral resolution. Vibrational and rotational analyses have yielded accurate spectroscopic constants of the X10+ and b0+ states (in cm−1): X10+: ωe=371.296(4), ωexe=1.3302(9), Be=0.1194117(2), αB=−0.0005676(7), De=4.56(2) ×10−8; b0+: Te=11136.921(4), ωe=400.165(6), ωexe=1.345(2), Be=0.1239237(2), αB=−0.0005540(2), De=4.84(5) × 10−8, where the numbers in parentheses are the standard deviations of the parameters. No emissions of the b0+→X21 sub-system nor of the a1Δ(a2)→X3Σ−(X21) transition have been observed leaving PI the only group Va halide for which the spin splitting in the X3Σ− ground state is still unknown. 相似文献
15.
The B2Σ+ → X2Σ+ (0-1, 2, 3, 4 progression) electronic transition of 12C17O+ was first observed and analyzed by Szajna and Ke¸pa [Spectrochim. Acta A 65 (2006) 1014-1020]. We have now extended our previous studies. The use of high resolution conventional spectroscopic techniques has allowed first rotational analysis of the 1-2, 1-3, 1-4 and 1-5 bands of the first negative system in the 37,000-43,000 cm−1 spectral region. Approximately 500 transition wavenumbers were measured with an estimated accuracy of 0.005 cm−1. The present data were combined with the previous measurements to yield an improved set of molecular constants for the B2Σ+(v′ = 0, 1) and X2Σ+(v″ = 1, 2, 3, 4, 5). The v′ = 1 and v″ = 5 vibrational levels were observed for the first time and the main molecular constants are (in cm−1, one standard deviation in parentheses)
B2Σ+ X2Σ+ B1 = 1.710792(20) B5 = 1.825694(23) D1 = 7.799(15) × 10−6 D5 = 6.085(21) × 10−6 γ1 = 1.9491(37) × 10−2 γ5 = [8.381] × 10−3 - Full-size table
16.
A combined analysis of the A2Πi → X2Σ+ and B2Σ+ → X2Σ+ band systems of AlO, involving 21,500 line assignments, has been performed. The analysis indicates that the previously reported γ values of the B2Σ+ state are questionable. The present analysis shows that γ(B2Σ+) ≈ 0.014 cm−1, essentially independent of the vibrational level. The positive sign is consistent with second order interaction with the higher-lying C2Πr and lower-lying A2Πi states. It also appears that many of the previously reported γ and γD values of X2Σ+ (v > 0) are doubtful. In fact, γ(X2Σ+) is observed to become increasingly negative for v″ > 1, due to second order interaction with the low-lying A2Πi state. The present results are based on models where the hyperfine structure of the 2Σ+ states has been taken into account explicitly. Intensity patterns of the branches of the B2Σ+ → X2Σ+ system have been shown to be influenced by the case bβS coupling in the ground state v = 0,1 levels. This gives rise to intensity differences of around 10 percent in the R1/R2 and P1/P2 doublet components. The synthesized intensity patterns are fully in accord with the F1/F2 assignments of the present work. 相似文献
17.
The spectrum of holmium monofluoride (HoF) in the blue (420-480 nm) region has been studied using laser-induced fluorescence. Previous work [J. Phys. B 7 (1974) L234] had assigned several bands in this region to the B8-X8 transition. By obtaining wavelength selected laser excitation spectra at high resolution and rotationally analyzing seven bands in this region, we have shown that not all the bands previously assigned to the B8-X8 system belong to the same electronic transition and have identified three separate transitions which we have labelled B8-X8, B′8-X8, and C7-X27. Preliminary low resolution dispersed fluorescence spectra have shown several excited states at energies greater than 4000 cm−1 above the ground state and, though not all could be assigned, ligand field theory calculations are consistent with assigning them to the first excited spin-orbit component of the Ho+(4f106s2)F− ground state configuration or to the first excited configuration, Ho+(4f116s)F−. The results of the dispersed fluorescence experiments also tentatively place the X27 state at ∼70 cm−1 above the ground X7 state. 相似文献
18.
The reaction of O- and N-atoms produces NO(C2Π) molecules by inverse predissociation. At low total pressure NO(A2Σ+) molecules are exclusively formed from NO(C2Π) by
(4) The population of NO(A2Σ+) is determined by the radiative steady-state. By measuring the intensities of the NO(C2Π → X2Π)−δ−bands and the NO(A2Σ+ → X2Π)-γ−bands the oscillator strengths for the NO(C2Π → A2Σ+) transition is derived. The result is f = 0.61. 相似文献
NO(C2Π) → NO(A2Σ+)+hv
19.
J. Borkowska-Burnecka W. ?yrnicki E.H. Fink 《Journal of Quantitative Spectroscopy & Radiative Transfer》2008,109(9):1599-1606
Rotational and vibrational temperatures of electronically excited BiN radicals in a low-pressure Bix+N/N2*/N2+Ar chemiluminescent flame have been deduced from high-resolution Fourier-transform emission spectra. Bands of three electronic transitions, a3Σ+(a11)→X1Σ+(X0+), b5Σ+(b10+)→X1Σ+(X0+), and b5Σ+(b10+)→a 3Σ+(a11), were analysed to determine the optical temperatures in the a3Σ+(a11) and b5Σ+(b10+) states. The rotational temperatures characterising the rotational populations in the a11, v=0 and 1 states were determined from the a1→X, 0-2, 0-3, 0-4, 1-1, and 1-2 bands. The b1→X, 0-8 and 0-11 bands, and the b1→a1, 0-0 bands served to determine the rotational temperature of the radicals in the b10+, v=0 state. The temperatures derived from the various bands and transitions were well consistent and the mean rotational temperature was determined to be 353±18 K, which is close to the translational temperature of the gas.Vibrational temperatures of the radicals in the a11 and b10+ states were derived from band intensities of the a1→X and from the b1→X as well as b1→a1 systems, respectively. The Franck-Condon factors needed were calculated with RKR potentials deduced from literature values of the rotational and vibrational constants in the three states involved. The a11 vibrational temperature (336±21 K) was close to the rotational temperature, while the b10+ vibrational temperature (438±36 K) differed, likely due to the previously observed perturbation of the b10+ state. 相似文献
20.
High resolution (3 + 1) and (2 + 1)REMPI spectra of HCl and DCl for total current detection at room temperature or TOF mass detection after jet cooling were recorded for the spectral region 89 000-89 600 cm−1. Analysis of the (3 + 1)REMPI spectra by use of three-photon absorption modeling allowed, for the first time, identification and characterization of the l (3Φ3) states. Consistent anomalies in spectral structures due to transitions to the j (3Σ−) (0+) state are interpreted as being due to interactions with the V (1Σ+) ion-pair states. Interaction strengths are evaluated. Simulation analyses and determination of isotope shifts allowed evaluation of vibrational and rotational spectroscopic parameters for the l (3Φ3) and the j (3Σ−) (0+) states for both molecules. 相似文献