Reinvestigation of the Cordes band system of I2 using a vacuum ultraviolet laser

doi:10.1016/0301-0104(90)89059-Y

Chemical Physics

Volume 140, Issue 1, 1 January 1990, Pages 187-193

https://doi.org/10.1016/0301-0104(90)89059-Y Get rights and content

Abstract

Vacuum ultraviolet (VUV) fluorescence excitation spectra of jet-cooled I₂ between 195 and 168 nm were recorded using a tunable VUV “laser” generated by four-wave difference mixing in Xe gas and Hg vapor. The strongest absorption in the VUV is between the ground state and the first tier ion-pair state D0_u⁺ (Cordes band system). Band edge wavenumbers measured in this work confirm the vibrational numbering proposed by Tellinghuisen for the VUV spectrum. D state levels between ν′ = 140 and 290 were excited and molecular constants valid between ν′ = 0 and 290 were derived. Perturbed D levels having ν′⩾309 were also observed. Their band intensities appear to be related to homogeneous interactions with the e₆ Rydberg state.

References (30)

J. Tellinghuisen
Chem. Phys. Letters
(1983)
R.H. Lipson et al.
Chem. Phys. Letters
(1988)
R.H. Lipson et al.
J. Mol. Spectry.
(1989)
J. Hager et al.
Chem. Phys. Letters
(1982)
A.R. Hoy et al.
Chem. Phys.
(1986)
R.J. Donovan et al.
Chem. Phys. Letters
(1987)
A.D. Williamson et al.
Chem. Phys. Letters
(1979)
R.J. Donovan et al.
Chem. Phys. Letters
(1985)
D.I. Austin et al.
Chem. Phys.
(1987)
B.V. O'Grady et al.
Chem. Phys. Letters
(1985)

J.C.D. Brand et al.

Appl. Spectros. Rev.

(1987)

H. Cordes

Z. Physik

(1935)

S. Mulliken

J. Chem. Phys.

(1971)

K.P. Huber et al.

Constants of Diatomic Molecules

(1979)

P. Venkateswarlu

Can. J. Phys.

(1970)

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A substantially-bound (D_e ∼ 7000 cm⁻¹, R_e ∼ 3.1 Å, T_e ∼ 60 546 cm⁻¹) 6s Rydberg state of I₂ with $0_{u}^{+}$ symmetry based on the lowest excited state of the ion core, previously labelled $a (^{4} Σ_{u, 1 / 2}^{-})$ , has been identified using optical triple resonance via the $B (0_{u}^{+}) and E 0_{g}^{+} (^{3} P_{2})$ states together with resonance ionization. The interactions with ground-core Rydberg states that the new state undergoes and the reasons why it is observed in the resonance ionization spectrum via the $E 0_{g}^{+} (^{3} P_{2})$ state, whilst the $A [^{2} Π_{u, 1 / 2}]_{c}; 6 s 0_{u}^{+}$ state is not, are explained in terms of its electronic configuration.
The D state of I<inf>2</inf>: A case study of statistical error propagation in the computation of RKR potential curves, spectroscopic constants, and Frank-Condon factors
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Existing spectroscopic data for the $D 0_{u}^{+} (^{3} P_{2})$ ion-pair state of I₂ are reanalyzed with the primary goal of improving and extending to higher υ the rotational constants B_υ. To this end, data for several precisely known (υ,J) levels in the υ=203–207 region are analyzed together with vibrational and rotational data from a number of sources. The lack of rotational data for the υ=130–200 region makes the structure of this data set unusual, and has prompted a thorough study of the propagated statistical error in the directly fitted spectroscopic constants, T_υ and B_υ, and in the RKR potential curve calculated therefrom. For the first time, such error propagation computations have been extended to properties computed by numerical solution of the Schrödinger equation for the state in question: the quantum vibrational energy G_υ and rotational constant B_υ, centrifugal distortion constants D_υ and H_υ, and Franck–Condon factors for the D–X transition.
Vibrational wavepacket motion in I <inf>2</inf> excited with femtosecond laser pulses in the 200 nm wavelength region
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Using 130 fs laser pulses with a photon energy of about 6.2 eV, vibrational wavepackets in high-lying electronic states of the iodine molecule are excited and observed by the pump–probe technique. The coherent vibrational motion with a frequency of about 60 cm⁻¹ first experiences a collapse. Furthermore, two distinct revivals are observed attributed to the vibrational motion on the D(0_u⁺) and, most probably, on the β(1_g) ion-pair potential energy curves. The different behaviour of jet-cooled and warm molecules is discussed.
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^☆: Publication 420 from the Photochemistry Unit, University of Western Ontario, Canada.

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Chemical Physics

Abstract

References (30)

Chem. Phys. Letters

Chem. Phys. Letters

J. Mol. Spectry.

Chem. Phys. Letters

Chem. Phys.

Chem. Phys. Letters

Chem. Phys. Letters

Chem. Phys. Letters

Chem. Phys.

Chem. Phys. Letters

Appl. Spectros. Rev.

Z. Physik

J. Chem. Phys.

Constants of Diatomic Molecules

Can. J. Phys.

Cited by (21)

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Vibrational wavepacket motion in I <inf>2</inf> excited with femtosecond laser pulses in the 200 nm wavelength region

Rotational perturbations in the (2 + 1) REMPI spectrum of the Rydberg state [<sup>2</sup>II<inf>3/2</inf>]<inf>c</inf>5d; 1g of I<inf>2</inf>

Improved spectroscopic constants for I<inf>2</inf> D <sup>1</sup>Σ<inf>u</inf><sup>+</sup>

REMPI spectra of I<inf>2</inf>. The [<inf> 3 2</inf>]<inf>c</inf>5d; 1g Rydberg state and interactions with ion pair states

Reinvestigation of the Cordes band system of I2 using a vacuum ultraviolet laser☆

Abstract

Chem. Phys. Letters

Chem. Phys. Letters

J. Mol. Spectry.

Chem. Phys. Letters

Chem. Phys.

Chem. Phys. Letters

Chem. Phys. Letters

Chem. Phys. Letters

Chem. Phys.

Chem. Phys. Letters

Appl. Spectros. Rev.

Z. Physik

J. Chem. Phys.

Constants of Diatomic Molecules

Can. J. Phys.

Reinvestigation of the Cordes band system of I₂ using a vacuum ultraviolet laser☆