Rotational and vibrational analysis of bands of the f1Δ-a1Δ system of titanium oxide

Five new bands of the f¹Δ-a¹Δ TiO system have been observed in emission between 17774.0 cm^?1 and 19801.0 cm^?1. Rotational and vibrational analyses of the 0-1, 1-0, 1-2, 2-1, and 1-1 bands, as well as a reanalysis of the 0-0 band, yielded the following molecular constants (cm^?1):

     

2.

Laser spectroscopy of CaBr: A²Π-X²Σ⁺ and B²Σ⁺-X²Σ⁺ systems     

P.F. Bernath  R.W. Field  B. Pinchemel  Y. Lefebvre  J. Schamps 《Journal of Molecular Spectroscopy》1981,88(1):175-193

Laser excitation spectra have been recorded for Ca⁷⁹Br and Ca⁸¹Br in the spectral region 600–630 nm. The use of a 1-m monochromator as a narrow band pass filter (1–2 cm^?1) has allowed rotational analysis of the 0-0, 1-1, and 2-2 bands of the B²Σ⁺ - X²Σ⁺ transition and the 0-0 and 1-1 bands of the A²Π - X²Σ⁺ transition. A few additional lines of the 0-1, 1-2, 1-0, and 2-1 bands of the B-X system were used to obtain band origins for vibrational analysis. The main constants for Ca⁷⁹Br are (in cm^?1):

		$\text{f}{}^1\text{Δ}$		$\text{a}{}^1\text{Δ}$
v	$\text{B}{}_{\mathrm{v}}$	$\text{D}{}_{\mathrm{v}}$ (×106)	$\text{B}{}_{\mathrm{v}}$	$\text{D}{}_{\mathrm{v}}$ (×106)
0	0.502277 (17)	0.6411 (57)	0.536168 (20)	0.5938 (76)
1	0.499198 (32)	0.630 (15)	0.533227 (13)	0.5971 (46)
2			0.530335 (26)	0.636 (13)
	$\text{ω}{}_{\mathrm{e}}\text{= 874.104 (4)}$		$\text{ω}{}_{\mathrm{e}}\text{= 1018.273 (4)}$
	$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}\text{= 2.501 (4)}$		$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}\text{= 4.521 (4)}$
	$\text{T′}{}_{\mathrm{e}}\text{?T″}{}_{\mathrm{e}}\text{= 19140.567 (8)}$

     

3.

Optical-optical double-resonance spectroscopy of BaO: The low-lying states     

Richard A. Gottscho  J. Brooke Koffend  Robert W. Field 《Journal of Molecular Spectroscopy》1980,82(2):310-338

Optical-optical double-resonance (OODR) induced photoluminescence into the lowest excited electronic states of BaO—a³Σ⁺, A¹Σ⁺, b³Π, and $\text{A′}{}^1\text{Π}$—from C¹Σ⁺ is described. These low-lying states are deperturbed to obtain spectroscopic constants and potential energy curves:

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^2\text{Π}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	15 958.41 (10)	16 383.137 (6)
$\text{ω}{}_{\mathrm{e}}$	285.732 (9)	288.56 (20)	285.747 (9)
$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	0.840 (4)	—	0.954 (4)
$\text{B}{}_{\mathrm{e}}$	0.094466141 (30)	0.0957343 (20)	0.0965151 (20)
$\text{α}{}_{\mathrm{e}}$	0.000403551 (40)	0.0004327 (20)	0.0004483 (15)
$\text{γ}{}_{\mathrm{e}}$ (spin-rot.)	0.00301484 (50)	—	0.068767 (79)
$\text{P}{}_{\mathrm{e}}$	—	?0.066834 (64)	—
$\text{A}{}_{\mathrm{e}}$	—	59.175 (1)	—

     

4.

High-resolution laser excitation spectroscopy: Analysis of the B2Σ+-X2Σ+ system of CaCl     

Peter J. Domaille  Timothy C. Steimle  Ning Bew Wong  David O. Harris 《Journal of Molecular Spectroscopy》1977,65(3):354-365

Single-mode cw dye laser excitation spectra of the (0, 0), (1, 1), and (2, 2) bands of the B²Σ⁺-X²Σ⁺ system of CaCl have been observed and assigned. Some 300 independent photo-luminescence spectra have been used in making the rotational assignment and demonstrate the power of the technique of line-by-line analysis in unraveling complex spectra. Spectroscopic constants (cm^?1) obtained from a weighted least squares fit of the data are given below. Numbers in parentheses refer to 95% confidence limits in the last digit.

	$\text{a}{}^3\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^1\text{Σ}{}^{\mathrm{+}}$	$\text{b}{}^3\text{Π}$	$\text{A′}{}^1\text{Π}$
$\text{T}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	16 596(3)	16 807.345(10)	17 502.6(10)	17 619.7(2)
$\text{ω}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	469.0(7)	499.620(19)	447.62(8)	447.95(22)
$\text{ω}{}_{\mathrm{<mtext>e</mtext>}}\text{x}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	1.48(4)	1.716(8)	2.287(12)	2.139(8)
$\text{ω}{}_{\mathrm{<mtext>e</mtext>}}\text{y}{}_{\mathrm{<mtext>e</mtext>}}\text{× 10}{}^2\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$		2.14(9)		1.02(3)
$\text{B}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	0.2594(5)	0.2583908(26)	0.22426(16)	0.22385(16)
$\text{α}{}_{\mathrm{<mtext>e</mtext>}}\text{× 10}{}^3\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	1.44(5)	1.111(3)	1.18(4)	1.15(4)
$\text{γ}{}_{\mathrm{<mtext>e</mtext>}}\text{× 10}{}^6\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$		7.0(7)		?4.0(21)
$\text{R}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{A}\text{?}\text{)}$	2.1294(20)	2.133512(11)	2.2901(8)	2.2922(8)

     

5.

Deperturbation study of the 0_u⁺ symmetry states of As₂ observed in the energy range 39 000–45 000 cm⁻¹     

Pierre Perdigon  Françoise Martin 《Journal of Molecular Spectroscopy》1980,83(1):40-63

The mutual perturbations of the A¹Σ_u⁺ and b0_u⁺ states of As₂ are due to a strong spin-orbit interaction. The numerical treatment of these perturbations leads to the following parameters:

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	16856.69(2)
$\text{ω}{}_{\mathrm{e}}$	369.8(10)	366.8(10)
$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$	1.13(20)	1.28(20)
$\text{B}{}_{\mathrm{e}}$	0.15200(54)	0.15448(54)
$\text{α}{}_{\mathrm{e}}$	0.00063(34)	0.00073(35)
$\text{D}{}_{\mathrm{e}}$	1.027(16) × 10?7	1.097(17) × 10?7
$\text{γ}{}_{\mathrm{e}}$ (spin-rotation)	+0.003	?0.0630(16)

     

6.

Vibration-rotation and deperturbation analysis of A²Π-X²Σ⁺ and B²Σ⁺-X²Σ⁺ systems of the CaI molecule     

David E Reisner  Peter F Bernath  R.W Field 《Journal of Molecular Spectroscopy》1981,89(1):107-124

Doppler-limited laser excitation spectroscopy employing narrow-band fluorescence detection was used to obtain a rotational and vibrational analysis in the (0, 0) and (1, 1) bands of the A²Π-X²Σ⁺ system and the (4, 2) (3, 1), (0, 0), (0, 1), (1, 2), (2, 3), and (3, 4) bands of the B²Σ⁺-X²Σ⁺ system of CaI. The A and B states are deperturbed to obtain spectroscopic constants and Franck-Condon factors. Deperturbation was necessary because of the small separation of the A and B states relative to the A ～ B interaction strength and the A²Π spin-orbit splitting. The main deperturbed constants (in cm^?1) are

	$\text{T}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{ω}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{B}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$
$\text{A}{}^1\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$	40 806 (3)	297 (2)	5.1 (2)	0.0798 (12)
$\text{b0}{}_{\mathrm{u}}{}^{\mathrm{+}}$	38 884 (3)	422 (1)	8.8 (1)	0.0783 (12)

     

7.

Ar⁺ laser-induced fluorescence spectra of Cs₂: The E¹Σ_u⁺ and (1) ¹Π_g electronic states     

C. Amiot  C. Crépin  J. Vergès 《Journal of Molecular Spectroscopy》1984,107(1):28-47

Laser-induced fluorescence of Cs₂ molecules in the infrared (1.15–2.5 μm) and the visible (505–545 nm) regions has been observed using several excitation wavelengths from an argonion laser. Accurate molecular constants and potential energy curves for the pumped E¹Σ_u⁺ state and the first excited gerade ¹Π state are derived from more than 1300 fluorescence lines precisely measured with a high-resolution Fourier transform interferometer. The main molecular constants for the states are

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^2\text{Π}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	15 624.67(5)	15 700.52(12)
$\text{ω}{}_{\mathrm{e}}$	238.7496(33)	241.19(7)	242.63(17)
$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	0.62789(64)	0.53(5) (Pekeris)	1.17(12) (Pekeris)
$\text{B}{}_{\mathrm{e}}$	0.0693254(84)	0.070460(14)	0.071572(22)
$\text{α}{}_{\mathrm{e}}\text{× 10}{}^4$	2.640(35)	2.15(10)	3.95(2)
$\text{A}{}_{\mathrm{e}}$	—	45.8968(52)	—
$\text{R}{}_{\mathrm{e}}\text{(}\text{A}\text{?}\text{)}$	2.8286(2)	2.8057(3)	2.7839(4)

     

8.

The A1Π-X1Σ band system of CD+: Spectroscopic constants and isotope shifts     

A. Antić-Jovanović  V. Bojović  D.S. Pešić  S. Weniger 《Journal of Molecular Spectroscopy》1979,75(2):197-204

Six bands of the A¹Π-X¹Σ system of CD⁺ in the region 3800–4800 Å have been recorded in emission using an aluminum hollow-cathode discharge in the HeC₂H₂ mixture. From the vibrational and rotational analysis of the observed bands, the following constants (cm^?1) are obtained:

	$\text{T}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{ω}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{B}{}_{\mathrm{e}}\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{R}{}_{\mathrm{e}}\text{(}\text{A}\text{?}\text{)}$
$\text{E}{}^1\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$	20195.23	29.10	0.00891	5.340733
(1) ${}^1\text{Π}{}_{\mathrm{g}}$	13913.42	18.44	0.00781	5.697722

     

9.

Observation of the v = 0–13 levels of Na₂b³Π_u by OODR ³Λ_g-b³Π_u fluorescence spectroscopy     

Li Li  S.F. Rice  R.W. Field 《Journal of Molecular Spectroscopy》1984,105(2):344-350

The absolute vibrational numbering of the Na₂b³Π_u state has been established by direct observation of the v = 0–13 levels. These b³Π_u levels appear as the lower levels in rotationally resolved fluorescence spectra resulting from OODR excitation of ³Π_g, ³Δ_g, and ³Σ_g⁺ states via b³Π_u ～ A¹Σ_u⁺ mixed intermediate levels. The molecular constants for the Na₂b³Π_u state are (in cm^?1, one standard error in parentheses)

		$\text{T}{}_{00}$		$\text{ω}{}_{\mathrm{e}}$		$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$		$\text{ω}{}_{\mathrm{e}}\text{y}{}_{\mathrm{e}}$		$\text{B}{}_{\mathrm{e}}$		$\text{D}{}_{\mathrm{e}}\text{·10}{}^4$		$\text{α}{}_{\mathrm{e}}$
$\text{A}{}^1\text{Π}$		23 747.5		1367.3		60.6		0.75		6.428		5.7		0.388
$\text{X}{}^1\text{Σ}$		0		2035						7.650		4.1		0.190
				(2101.6)		(33.3)

     

10.

The A3Π-X0+, 1 band system of the SeO molecule     

K.K. Verma  M. Azam  S.Paddi Reddy 《Journal of Molecular Spectroscopy》1977,65(2):289-294

A new weak emission band system of the SeO molecule consisting of 34 band heads degraded to shorter wavelengths has been observed for the first time in the spectral region 6730–8570 Å. The vibrational analysis of the system suggests that it arises from the transition A³Π_reg-X0⁺, 1. All the five subsystems allowed by the selection rule $\text{ΔΩ}\text{= 0}$, ±1 have been identified. The constants in cm^?1 derived for the A³Π state are

$\text{T}{}_{\mathrm{e}}$	13 517.2 (1.3)	$\text{B}{}_{\mathrm{e}}$	0.1434 (0.0027)
$\text{ω}{}_{\mathrm{e}}$	153.6 (1.1)	$\text{α}{}_{\mathrm{e}}$	9×10?5 (4×10?4)
$\text{ω}{}_{\mathrm{e}}\text{ξ}{}_{\mathrm{e}}$	0.47 (0.09)	$\text{r}{}_{\mathrm{e}}$	3.20 (0.03) Å
$\text{A}{}_{\mathrm{e}}$	7.85 (0.60)	$\text{α}{}_{\mathrm{A}}$	0.19 (0.16)

     

11.

Stark spectroscopy with the CO₂ laser: The ν₃ band of CD₃F     

G. Duxbury  S.M. Freund  J.W.C. Johns 《Journal of Molecular Spectroscopy》1976,62(1):99-108

The ν₃ band of CD₃F has been studied using coincidences with the 10.4 μm band of the CO₂ laser. The majority of the 150 resonances measured have been studied using the Lamb dip technique. These resonances have been analyzed, together with recent microwave results, to give the following vibration-rotation parameters and dipole moments in the ν₃ state.

	$\text{T}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$
$\text{A}{}_3{}^3\text{Π}{}_2$	16 758	$\text{Δ}\text{G(}\text{1}\text{2}\text{) = 980}$
$\text{A}{}_2{}^3\text{Π}{}_1$	16 442	996	7.0
$\text{A}{}_1{}^3\text{Π}{}_0$	16 131	994	6.5

     

12.

The rotation-inversion spectrum of ¹⁵NH₃     

M. Carlotti  A. Trombetti  B. Velino  J. Vrbancich 《Journal of Molecular Spectroscopy》1980,83(2):401-407

The rotation-inversion spectrum of ¹⁵NH₃ has been recorded between 38 and 280 cm^?1 with a resolution of about 0.03 cm^?1. By combining the present results with the inversion frequencies obtained by microwave spectroscopy, the following main rotational and centrifugal distortion constants were derived (in cm^?1):

	12CD3F
$\text{ν}{}_0$	992.29882 (19)	cm?1
$\text{B}$	20395.776 ± 0.08	MHz
$\text{A-A}{}_0$	?35.73 ± 0.61	MHz
$\text{D}{}_{\mathrm{J}}$	33.8 ± 0.5	kHz
$\text{D}{}_{\mathrm{JK}}$	203.9 ± 7	kHz
$\text{μ}{}_{\mathrm{\nu 3}}$	1.8964 ± 0.0015	D
$\text{μ}{}_{\mathrm{\nu 3}}\text{? μ}{}_0$	0.02617 ± 0.0005	D

     

13.

Optical-optical double-resonance spectroscopy of BaF: The E²Σ⁺ and F²Π states     

Precila C.F Ip  Peter F Bernath  Robert W Field 《Journal of Molecular Spectroscopy》1981,89(1):53-61

Sub-Doppler optical-optical double-resonance excitation spectra of BaF were recorded using two single-mode cw dye lasers. In the 30 000-cm^?1 region, the electronic states observed were E²Σ⁺ and F²Π. The latter had been previously assigned as the “F²Σ⁺” state by Fowler [Phys. Rev.59, 645–652 (1941)]. The (3, 0) and (4, 0) bands of the E²Σ⁺-B²Σ⁺ transition and the (1, 0) and (2, 0) bands of the F²Π-B²Σ⁺ transition were rotationally analyzed. The molecular constants suggest inferences about the dominant atomic orbital character of the Rydberg molecular orbitals responsible for the E²Σ⁺ and F²Π electronic states. A new electronic state, the $\text{E′}{}^2\text{Π}$, is predicted. The molecular parameters obtained (in cm^?1, 1σ uncertainty in parentheses) are

State	$\text{B}$	$\text{D}{}_{\mathrm{J}}$	$\text{D}{}_{\mathrm{JK}}$
$\text{v}{}_{\mathrm{<mtext>inv</mtext>}}\text{= 0}$	9.92235	0.0008493	?0.001575
$\text{v}{}_{\mathrm{<mtext>inv</mtext>}}\text{= 1}$	9.91742	0.0008336	?0.001532

     

14.

Continuous wave dye laser excitation spectroscopy CaF A2Πr-X2Σ+     

Robert W. Field  David O. Harris  Takehiko Tanaka 《Journal of Molecular Spectroscopy》1975,57(1):107-117

Excitation spectra for the CaF A²Π-X²Σ(0, 0), (1, 1), and (1, 0) bands have been observed and assigned. The rotational analysis of the CaF A-X and B-X bands by B. S. Mohanty and K. N. Upadhya [Ind. J. Pure Appl. Phys.5, 523 (1967)] is shown to be incorrect. Because it is possible to make independent rotational assignments of each line in an excitation spectrum by observing frequency differences and relative intensities in photoluminescence spectra, tunable laser excitation spectroscopy promises less ambiguity than traditional techniques for assignment of dense, badly overlapped spectra.The following spectroscopic constants (in cm^?1) are obtained for the CaF A²Π and X²Σ states. Numbers in parentheses correspond to three standard deviations uncertainty in the last digit.

	$\text{v′}{}_{\mathrm{E}}$	$\text{E}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{v′}{}_{\mathrm{F}}$	$\text{F}{}^2\text{Π}$
$\text{T}{}_{\mathrm{v\prime 0}}$	3	29 767.32(1)	1	29 997.29(1)
$\text{Δ}\text{G}{}_{\mathrm{<mtext>v\prime \; +\; </mtext><mtext>1</mtext><mtext>2</mtext>}}$	3	522.841(27)	1	522.553(2)
$\text{B}{}_{\mathrm{e}}$		0.22990(22)		0.22931(8)
$\text{α}{}_{\mathrm{e}}$		0.00113(14)		0.00108(2)
$\text{A}{}_{\mathrm{v\prime }}$			1	56.9840(12)
$\text{p}{}_{\mathrm{v\prime }}$			1	?0.02426(6)
$\text{γ}{}_{\mathrm{v\prime }}$	3	?0.17367(46)

     

15.

The ν₃ fundamental band of HDCO     

J.W.C Johns  A.R.W McKellar 《Journal of Molecular Spectroscopy》1977,64(2):327-339

The ν₃ fundamental band (CO stretch) of HDCO at 1724 cm^?1 has been studied using both conventional infrared absorption and CO laser Stark spectroscopy. In addition to the excited-state (v₃ = 1) rotational constants, improved constants for the ground state of HDCO have been obtained by combining previous microwave data with some infrared combination differences. The following constants were determined:

	$\text{X}{}^2\text{Σ}$		$\text{A}{}^2\text{Π}$
$\text{ν}{}_{00}$	0	${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	16493.1(6)
		${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	16565.6(6)
$\text{Δ}\text{G(}\text{1}\text{2}\text{)}$	581.1(9)	${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	586.8(9)
$\text{B}{}_{\mathrm{e}}$	0.3385(11)		0.3436(12)
$\text{B}{}_{\mathrm{e}}\text{(}\text{Ω}\text{=}\text{3}\text{2}\text{) ? B}{}_3\text{(}\text{Ω}\text{=}\text{1}\text{2}\text{)}$	—		0.00312(21)
α	0.00255(48)		0.00283(45)
$\text{D(}\text{estimated}\text{)}$	4.44 × 10?7		4.55 × 10?7
γ(spin-spin)	|γ| < 3 × 10?3		—
$\text{A}{}_0\text{(}\text{spin-orbit}\text{)}$	—		73.4(9)
$\text{p(}\text{lambda doubling}\text{)}$	—		?0.045(4)

     

16.

The emission spectrum of SeO in the far ultraviolet     

S.Paddi Reddy  M. Azam 《Journal of Molecular Spectroscopy》1974,49(3):461-467

The emission spectrum of SeO in the far ultraviolet first observed by Haranath (1) at low dispersion has been photographed in the region 2480-1930 Å under medium resolution and a reanalysis of the vibrational structure of the bands has been presented. Beginning at the longer wavelength end, the spectrum has been analyzed into five band systems which are designated as $\text{c(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)-b(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)}$, x₂-x₁, y₂-y₁, $\text{C(}{}^3\text{Π}\text{)-X}{}^3\text{Σ}{}^{\mathrm{?}}$, and $\text{D(}{}^3\text{Σ}{}^{\mathrm{?}}\text{)-X}{}^3\text{Σ}{}^{\mathrm{?}}$. The lower state of the c-b system is found to be the upper state of the $\text{b(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)-X}{}^3\text{Σ}{}^{\mathrm{?}}$ system observed recently by us (2). The derived constants in cm^?1 for SeO are as follows (the constants of the b state are those derived from Ref. 2).

Constant	Ground state	$\text{v}{}_3\text{= 1}$ state	Units
$\text{ν}{}_0$		1724.267	cm?1
$\text{A}$	198 119.75	198 210.4	MHz
$\text{B}$	34 910.646	34 676.6	MHz
$\text{C}$	29 561.488	29 331.3	MHz
$\text{μ}{}_{\mathrm{a}}$	2.3302	2.3486	D
$\text{μ}{}_{\mathrm{b}}$	0.195	0.190	D

     

17.

Laser Stark spectroscopy in the 10 μm region: The ν₃ bands of CH₃F     

S.M. Freund  G. Duxbury  M. Römheld  J.T. Tiedje  T. Oka 《Journal of Molecular Spectroscopy》1974,52(1):38-57

Laser Stark spectroscopy of the ν₃ band of CH₃F has been carried out using coincidences with the 9.4 μm band CO₂ laser lines. About 350 Stark resonances were measured for the ν₃ fundamental bands of ¹²CH₃F and ¹³CH₃F. About 30 of them were measured by using a Stark-Lamb dip technique to increase the resolution and the accuracy of the data. These Stark resonances, together with the recent results of infrared-microwave two-photon Lamb dip measurements, were analyzed to give the following vibration-rotation parameters and the dipole moments in the ν₃ state,

State	$\text{T}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$	λ
$\text{y}{}_2$	$\text{y}{}_1\text{+ 47830}$	974	6.0
$\text{y}{}_1$	$\text{y}{}_1$	906	21.0
$\text{x}{}_2$	$\text{x}{}_1\text{+ 46009}$	993	2.0
$\text{x}{}_1$	$\text{x}{}_1$	877	8.0
$\text{c(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)}$	53080	954	13.0
$\text{D(}{}^3\text{Σ}{}^{\mathrm{?}}\text{)}\text{F}{}_2$	51422	955	9.3
F1	51356	955	8.5	～36
$\text{C(}{}^3\text{Π}\text{)}$	50873	1034	9.3
$\text{b(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)}$	9570.7	834.9	5.5

     

18.

Laser spectroscopy of CuS: Analysis of the A²Σ-X²Π_i system     

F. David  M. Douay  Y. Lefebvre 《Journal of Molecular Spectroscopy》1985,112(1):115-126

Laser excitation spectra of the A²Σ-X²Π_i system have been recorded for ⁶³CuS and ⁶⁵CuS isotopic molecules with a single-mode dye laser operating in the region 17000–18000 cm^?1. For highly overlapped sequences, use of a monochromator as a narrow band filter was necessary to allow rotational analysis. A simultaneous fit of all eight analyzed bands has led to the following spectroscopic constants for ⁶³CuS (in cm^?1):

	12CH3F	13CH3F
$\text{ν}{}_0$	1048.610767 (62)	1027.493191 (69)	cm?1
$\text{B}$	25197.57 ± 0.03	24542.07 ± 0.43	MHz
$\text{A - A}{}_0$	?294.09 ± 0.60	?288.81 ± 0.37	MHz
$\text{D}{}_{\mathrm{J}}$	55.5 ± 1.2	56 ± 12	kHz
$\text{D}{}_{\mathrm{JK}}$	575 ± 63	464 ± 24	kHz
μ	1.9054 ± 0.0006	1.9039 ± 0.0006	$\text{D}$

     

19.

The A²Π-X²Π system of the SbO molecule     

Walter J Balfour  Ram S Ram 《Journal of Molecular Spectroscopy》1984,105(1):246-259

The emission spectrum of the A²Π-X²Π system of the SbO molecule has been photographed under high resolution, and the rotational structure in eight bands of the ${}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ component, involving v′ = 0–2 and v″ = 1–4, has been analyzed for both isotopic molecules ¹²¹SbO and ¹²³SbO. The observed rotational lines of the corresponding ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ component are broad, with a width of about 0.2 cm^?1 varying little with J. It is suggested that these broad lines represent unresolved components arising from magnetic hyperfine interaction with ¹²¹Sb or ¹²³Sb nuclei. Isotopic shift observations contradict earlier vibrational assignments in the ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ subsystem and indicate that the A state is inverted in agreement with expectations from related systems. The principal molecular constants (in cm^?1) obtained for ¹²¹SbO are

State	$\text{v}$	$\text{T}{}_{\mathrm{v}}$	$\text{B}{}_{\mathrm{v}}$	$\text{D}{}_{\mathrm{v}}\text{× 10}{}^6$	$\text{γ}{}_{\mathrm{v}}$	$\text{p}{}_{\mathrm{v}}$	$\text{a}{}_{\mathrm{v}}\text{× 10}{}^6$
$\text{A}{}^2\text{Σ}{}^{\mathrm{?}}$	0	17924.335 (7)	0.17989 (4)	0.177 (7)	0.03853 (7)
$\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	1	842.574 (7)	0.18701 (4)	0.163 (7)		0.01496 (9)
	0	432.566 (6)	0.18818 (4)	0.162 (7)		0.01508 (9)
$\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$	1	411.289 (7)	0.18724 (4)	0.184 (7)			?0.96 (6)
	0	—	0.18839 (4)	0.160 (7)			?0.11 (6)

     

20.

The ν₁ and 3ν₁ bands of HNCO     

M. Carlotti  G. di Lonardo  G. Galloni  A. Trombetti 《Journal of Molecular Spectroscopy》1976,62(2):192-200

The infrared absorption of HNCO has been measured in the region of the NH stretching fundamental and in that of the second overtone. The results for the excited states are (in cm^?1):

State	$\text{T}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	$\text{B}{}_{\mathrm{e}}$	$\text{10}{}^3\text{α}{}_{\mathrm{e}}$	$\text{10}{}^7\text{D}{}_{\mathrm{e}}$
$\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	0	818.7	4.2	—	—	—
$\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$	x ≈ 2272	814.1	4.3	0.35920	2.38	2.8
$\text{A}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	21 467.4	565.8	2.9	—	—	—
$\text{A}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$	x + 18 521.7	570.4	2.6	0.28856	1.82	2.9

     

Band	$\text{ν}{}_0$	$\text{A-}\text{B}$	B	C
$\text{ν}{}_1$	3533.1	27.0	—	—
$\text{3ν}{}_1$	10145.79	22.6713	0.368426	0.361722

Laser spectroscopy of CaBr: A2Π-X2Σ+ and B2Σ+-X2Σ+ systems

Laser excitation spectra have been recorded for Ca⁷⁹Br and Ca⁸¹Br in the spectral region 600–630 nm. The use of a 1-m monochromator as a narrow band pass filter (1–2 cm^?1) has allowed rotational analysis of the 0-0, 1-1, and 2-2 bands of the B²Σ⁺ - X²Σ⁺ transition and the 0-0 and 1-1 bands of the A²Π - X²Σ⁺ transition. A few additional lines of the 0-1, 1-2, 1-0, and 2-1 bands of the B-X system were used to obtain band origins for vibrational analysis. The main constants for Ca⁷⁹Br are (in cm^?1):

Optical-optical double-resonance spectroscopy of BaO: The low-lying states

Optical-optical double-resonance (OODR) induced photoluminescence into the lowest excited electronic states of BaO—a³Σ⁺, A¹Σ⁺, b³Π, and $\text{A′}{}^1\text{Π}$—from C¹Σ⁺ is described. These low-lying states are deperturbed to obtain spectroscopic constants and potential energy curves:

High-resolution laser excitation spectroscopy: Analysis of the B2Σ+-X2Σ+ system of CaCl

Single-mode cw dye laser excitation spectra of the (0, 0), (1, 1), and (2, 2) bands of the B²Σ⁺-X²Σ⁺ system of CaCl have been observed and assigned. Some 300 independent photo-luminescence spectra have been used in making the rotational assignment and demonstrate the power of the technique of line-by-line analysis in unraveling complex spectra. Spectroscopic constants (cm^?1) obtained from a weighted least squares fit of the data are given below. Numbers in parentheses refer to 95% confidence limits in the last digit.

Deperturbation study of the 0u+ symmetry states of As2 observed in the energy range 39 000–45 000 cm−1

The mutual perturbations of the A¹Σ_u⁺ and b0_u⁺ states of As₂ are due to a strong spin-orbit interaction. The numerical treatment of these perturbations leads to the following parameters:

Vibration-rotation and deperturbation analysis of A2Π-X2Σ+ and B2Σ+-X2Σ+ systems of the CaI molecule

Doppler-limited laser excitation spectroscopy employing narrow-band fluorescence detection was used to obtain a rotational and vibrational analysis in the (0, 0) and (1, 1) bands of the A²Π-X²Σ⁺ system and the (4, 2) (3, 1), (0, 0), (0, 1), (1, 2), (2, 3), and (3, 4) bands of the B²Σ⁺-X²Σ⁺ system of CaI. The A and B states are deperturbed to obtain spectroscopic constants and Franck-Condon factors. Deperturbation was necessary because of the small separation of the A and B states relative to the A ～ B interaction strength and the A²Π spin-orbit splitting. The main deperturbed constants (in cm^?1) are

Ar+ laser-induced fluorescence spectra of Cs2: The E1Σu+ and (1) 1Πg electronic states

Laser-induced fluorescence of Cs₂ molecules in the infrared (1.15–2.5 μm) and the visible (505–545 nm) regions has been observed using several excitation wavelengths from an argonion laser. Accurate molecular constants and potential energy curves for the pumped E¹Σ_u⁺ state and the first excited gerade ¹Π state are derived from more than 1300 fluorescence lines precisely measured with a high-resolution Fourier transform interferometer. The main molecular constants for the states are

The A1Π-X1Σ band system of CD+: Spectroscopic constants and isotope shifts

Six bands of the A¹Π-X¹Σ system of CD⁺ in the region 3800–4800 Å have been recorded in emission using an aluminum hollow-cathode discharge in the HeC₂H₂ mixture. From the vibrational and rotational analysis of the observed bands, the following constants (cm^?1) are obtained:

Observation of the v = 0–13 levels of Na2b3Πu by OODR 3Λg-b3Πu fluorescence spectroscopy

The absolute vibrational numbering of the Na₂b³Π_u state has been established by direct observation of the v = 0–13 levels. These b³Π_u levels appear as the lower levels in rotationally resolved fluorescence spectra resulting from OODR excitation of ³Π_g, ³Δ_g, and ³Σ_g⁺ states via b³Π_u ～ A¹Σ_u⁺ mixed intermediate levels. The molecular constants for the Na₂b³Π_u state are (in cm^?1, one standard error in parentheses)

The A3Π-X0+, 1 band system of the SeO molecule

A new weak emission band system of the SeO molecule consisting of 34 band heads degraded to shorter wavelengths has been observed for the first time in the spectral region 6730–8570 Å. The vibrational analysis of the system suggests that it arises from the transition A³Π_reg-X0⁺, 1. All the five subsystems allowed by the selection rule $\text{ΔΩ}\text{= 0}$, ±1 have been identified. The constants in cm^?1 derived for the A³Π state are

Stark spectroscopy with the CO2 laser: The ν3 band of CD3F

The ν₃ band of CD₃F has been studied using coincidences with the 10.4 μm band of the CO₂ laser. The majority of the 150 resonances measured have been studied using the Lamb dip technique. These resonances have been analyzed, together with recent microwave results, to give the following vibration-rotation parameters and dipole moments in the ν₃ state.

The rotation-inversion spectrum of 15NH3

The rotation-inversion spectrum of ¹⁵NH₃ has been recorded between 38 and 280 cm^?1 with a resolution of about 0.03 cm^?1. By combining the present results with the inversion frequencies obtained by microwave spectroscopy, the following main rotational and centrifugal distortion constants were derived (in cm^?1):

Optical-optical double-resonance spectroscopy of BaF: The E2Σ+ and F2Π states

Sub-Doppler optical-optical double-resonance excitation spectra of BaF were recorded using two single-mode cw dye lasers. In the 30 000-cm^?1 region, the electronic states observed were E²Σ⁺ and F²Π. The latter had been previously assigned as the “F²Σ⁺” state by Fowler [Phys. Rev.59, 645–652 (1941)]. The (3, 0) and (4, 0) bands of the E²Σ⁺-B²Σ⁺ transition and the (1, 0) and (2, 0) bands of the F²Π-B²Σ⁺ transition were rotationally analyzed. The molecular constants suggest inferences about the dominant atomic orbital character of the Rydberg molecular orbitals responsible for the E²Σ⁺ and F²Π electronic states. A new electronic state, the $\text{E′}{}^2\text{Π}$, is predicted. The molecular parameters obtained (in cm^?1, 1σ uncertainty in parentheses) are

Continuous wave dye laser excitation spectroscopy CaF A2Πr-X2Σ+

Excitation spectra for the CaF A²Π-X²Σ(0, 0), (1, 1), and (1, 0) bands have been observed and assigned. The rotational analysis of the CaF A-X and B-X bands by B. S. Mohanty and K. N. Upadhya [Ind. J. Pure Appl. Phys.5, 523 (1967)] is shown to be incorrect. Because it is possible to make independent rotational assignments of each line in an excitation spectrum by observing frequency differences and relative intensities in photoluminescence spectra, tunable laser excitation spectroscopy promises less ambiguity than traditional techniques for assignment of dense, badly overlapped spectra.The following spectroscopic constants (in cm^?1) are obtained for the CaF A²Π and X²Σ states. Numbers in parentheses correspond to three standard deviations uncertainty in the last digit.

The ν3 fundamental band of HDCO

The ν₃ fundamental band (CO stretch) of HDCO at 1724 cm^?1 has been studied using both conventional infrared absorption and CO laser Stark spectroscopy. In addition to the excited-state (v₃ = 1) rotational constants, improved constants for the ground state of HDCO have been obtained by combining previous microwave data with some infrared combination differences. The following constants were determined:

The emission spectrum of SeO in the far ultraviolet

The emission spectrum of SeO in the far ultraviolet first observed by Haranath (1) at low dispersion has been photographed in the region 2480-1930 Å under medium resolution and a reanalysis of the vibrational structure of the bands has been presented. Beginning at the longer wavelength end, the spectrum has been analyzed into five band systems which are designated as $\text{c(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)-b(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)}$, x₂-x₁, y₂-y₁, $\text{C(}{}^3\text{Π}\text{)-X}{}^3\text{Σ}{}^{\mathrm{?}}$, and $\text{D(}{}^3\text{Σ}{}^{\mathrm{?}}\text{)-X}{}^3\text{Σ}{}^{\mathrm{?}}$. The lower state of the c-b system is found to be the upper state of the $\text{b(}{}^1\text{Σ}{}^{\mathrm{+}}\text{)-X}{}^3\text{Σ}{}^{\mathrm{?}}$ system observed recently by us (2). The derived constants in cm^?1 for SeO are as follows (the constants of the b state are those derived from Ref. 2).

Laser Stark spectroscopy in the 10 μm region: The ν3 bands of CH3F

Laser Stark spectroscopy of the ν₃ band of CH₃F has been carried out using coincidences with the 9.4 μm band CO₂ laser lines. About 350 Stark resonances were measured for the ν₃ fundamental bands of ¹²CH₃F and ¹³CH₃F. About 30 of them were measured by using a Stark-Lamb dip technique to increase the resolution and the accuracy of the data. These Stark resonances, together with the recent results of infrared-microwave two-photon Lamb dip measurements, were analyzed to give the following vibration-rotation parameters and the dipole moments in the ν₃ state,

Laser spectroscopy of CuS: Analysis of the A2Σ-X2Πi system

Laser excitation spectra of the A²Σ-X²Π_i system have been recorded for ⁶³CuS and ⁶⁵CuS isotopic molecules with a single-mode dye laser operating in the region 17000–18000 cm^?1. For highly overlapped sequences, use of a monochromator as a narrow band filter was necessary to allow rotational analysis. A simultaneous fit of all eight analyzed bands has led to the following spectroscopic constants for ⁶³CuS (in cm^?1):

The A2Π-X2Π system of the SbO molecule

The emission spectrum of the A²Π-X²Π system of the SbO molecule has been photographed under high resolution, and the rotational structure in eight bands of the ${}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ component, involving v′ = 0–2 and v″ = 1–4, has been analyzed for both isotopic molecules ¹²¹SbO and ¹²³SbO. The observed rotational lines of the corresponding ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ component are broad, with a width of about 0.2 cm^?1 varying little with J. It is suggested that these broad lines represent unresolved components arising from magnetic hyperfine interaction with ¹²¹Sb or ¹²³Sb nuclei. Isotopic shift observations contradict earlier vibrational assignments in the ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ subsystem and indicate that the A state is inverted in agreement with expectations from related systems. The principal molecular constants (in cm^?1) obtained for ¹²¹SbO are

The ν1 and 3ν1 bands of HNCO

The infrared absorption of HNCO has been measured in the region of the NH stretching fundamental and in that of the second overtone. The results for the excited states are (in cm^?1):