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Full dimensional Franck-Condon factors for the acetylene A ̃ 1Au —$$ \tilde{X} $$ 1Σ$$^+_g$$ transition. II. Vibrational overlap factors for levels involving excitation in ungerade modes

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4896533· OSTI ID:1546773
 [1];  [2];  [2]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Chemistry; Office of Scientific and Technical Information (OSTI)
  2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Chemistry
+ Show Author Affiliations
A full-dimensional Franck-Condon calculation has been applied to the A ̃ 1Au —$$ \tilde{X} $$ 1Σ$$^+_g$$ transition in acetylene in the harmonic normal mode basis. Details of the calculation are discussed in Part I of this series. To our knowledge, this is the first full-dimensional Franck-Condon calculation on a tetra-atomic molecule undergoing a linear-to-bent geometry change. In the current work, the vibrational intensity factors for levels involving excitation in ungerade vibrational modes are evaluated. Because the Franck-Condon integral accumulates away from the linear geometry, we have been able to treat the out-of-plane component of trans bend (ν$$^"_4$$) in the linear $$ \tilde{X} $$ state in the rotational part of the problem, restoring the χ Euler angle and the a-axis Eckart conditions. A consequence of the Eckart conditions is that the out-of-plane component of ν$$^"_4$$ does not participate in the vibrational overlap integral. This affects the structure of the coordinate transformation and the symmetry of the vibrational wavefunctions used in the overlap integral, and results in propensity rules involving the bending modes of the $$ \tilde{X} $$ state that were not previously understood. We explain the origin of some of the unexpected propensities observed in IR-UV laser-induced fluorescence spectra, and we calculate emission intensities from bending levels of the $$ \tilde{A} $$ state into bending levels of the $$ \tilde{X} $$ state, using normal bending mode and local bending mode basis sets. Our calculations also reveal Franck-Condon propensities for the Cartesian components of the cis bend (ν$$^"_5$$), and we predict that the best $$ \tilde{A} $$-state vibrational levels for populating $$ \tilde{X} $$-state levels with large amplitude bending motion localized in a single C–H bond (the acetylene↔vinylidene isomerization coordinate) involve a high degree of excitation in ν'6 (cis-bend). Mode ν'4 (torsion) populates levels with large amplitude counter-rotational motion of the two hydrogen atoms.
Research Organization:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sponsoring Organization:
USDOE Advanced Research Projects Agency - Energy (ARPA-E); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
FG02-87ER13671
OSTI ID:
1546773
Alternate ID(s):
OSTI ID: 1420702
OSTI ID: 22436553
Journal Information:
Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 13 Vol. 141; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (54)

The ν3 Fundamental in C2H2 journal February 1993
Calculated Vibrational Intensities in the ÖX̃ Electronic Transition of Acetylene journal June 2001
Assignments of the 12C2H2 bands at 2.1–2.2μ journal January 1972
Investigations of several infrared bands of 12C2H2 and studies of the effects of vibrational rotational interactions journal October 1972
Spectrum of acetylene in the 5-micron region journal October 1972
Interpretation of the acetylene spectrum at 1.5 μm journal November 1977
The C2H2 absorption spectrum in the Nd laser range journal November 1980
The band system of acetylene journal September 1982
The band system of acetylene: Analysis of medium-wavelength bands, and vibration-rotation constants for the levels nν′3 (n = 4–6), ν′2 + nν′3 (n = 3–5), and ν′1 + nν′3 (n = 2, 3) journal May 1985
The band system of acetylene: Bands of the short-wavelength region journal September 1986
Spectroscopic constants for the 2.5 and 3.0 μm bands of acetylene journal June 1990
Analysis of the high-resolution spectrum of acetylene in the 2.4 μm region journal July 1991
The bending energy levels of C2H2 journal December 1991
A new ab initio potential energy surface describing acetylene/vinylidene isomerization journal January 2003
Trans–cis isomerization of acetylene in the Ã1Au state as studied by dispersed fluorescence spectroscopy journal June 1999
Stretch-bend combination polyads in the Ã1Au state of acetylene, C2H2 journal August 2009
IR−UV Double Resonance Spectroscopy of Acetylene in the à 1 A u n ν 3 ‘+ν 4 ‘ and n ν 3 ‘+ν 6 ‘ ( n = 2, 3) Ungerade Vibrational States † journal November 2000
Bending Dynamics of Acetylene:  New Modes Born in Bifurcations of Normal Modes † journal September 2006
Electronic Signatures of Large Amplitude Motions:  Dipole Moments of Vibrationally Excited Local-Bend and Local-Stretch States of S 0 Acetylene † journal September 2006
Accurate MRCI and CC Study of the Most Relevant Stationary Points and Other Topographical Attributes for the Ground-State C 2 H 2 Potential Energy Surface journal December 2010
High-Accuracy Estimates for the Vinylidene-Acetylene Isomerization Energy and the Ground State Rotational Constants of :C═CH 2 journal May 2013
Laser-Induced Fluorescence Study of the S 1 State of Doubly-Substituted 13 C Acetylene and Harmonic Force Field Determination journal September 2013
Dispersed Fluorescence Spectrum of Acetylene from the à 1 A u Origin:  Recognition of Polyads and Test of Multiresonant Effective Hamiltonian Model for the X̃ State journal January 1996
Acetylene at the Threshold of Isomerization journal April 2000
The Bent Excited State of Acetylene journal June 1952
549. Excited states of acetylene. Part I. Possibilities of interaction between σ-bond hybridisation and π-electron excitation with resulting changes of shape during transitions journal January 1953
The infrared-ultraviolet dispersed fluorescence spectrum of acetylene: New classes of bright states journal May 2001
Vibrational Spectroscopic Database on Acetylene, X̃ 1Σg+ (12C2H2, 12C2D2, and 13C2H2) journal September 2003
Analysis of the Near Ultraviolet Absorption Spectrum of Acetylene journal May 1954
Darling–Dennison resonance and Coriolis coupling in the bending overtones of the ÃAu1 state of acetylene, C2H2 journal August 2008
Reduced dimension discrete variable representation study of cis–trans isomerization in the S 1 state of C 2 H 2 journal June 2011
Cis-trans isomerization in the S 1 state of acetylene: Identification of cis-well vibrational levels journal June 2011
The C–H overtone spectra of acetylene: Bend/stretch interactions below 10 000 cm − 1 journal October 1988
A study of the singlet and triplet states of vinylidene by photoelectron spectroscopy of H 2 C=C − , D 2 C=C − , and HDC=C − . Vinylidene–acetylene isomerization journal November 1989
The direct observation, assignment, and partial deperturbation of the ν 4 and ν 6 vibrational fundamentals in A ̃  1 A u acetylene (C 2 H 2 ) journal February 1993
The direct observation, assignment, and partial deperturbation of ν 5 and ν 3 +ν 5 in A ̃  1 A u acetylene (C 2 H 2 ) journal July 1993
Normal modes analysis of A ̃‐state acetylene based on directly observed fundamental vibrations journal October 1993
The vibrational energy levels in acetylene 12 C 2 H 2 : Towards a regular pattern at higher energies journal April 1995
Highly vibrationally excited 12 C 2 H 2 in the X̃   1 ∑ + g state: Complementarity of absorption and dispersed fluorescence spectra journal December 1996
Pure bending dynamics in the acetylene X̃ 1Σg+ state up to 15 000 cm−1 of internal energy journal July 1998
Anomalously slow intramolecular vibrational redistribution in the acetylene X̃ 1Σg+ state above 10 000 cm−1 of internal energy journal September 1998
The vibrational energy pattern in acetylene (IV): Updated global vibration constants for 12C2H2 journal January 1999
Local mode behavior in the acetylene bending system journal January 1999
State-by-state assignment of the bending spectrum of acetylene at 15 000 cm −1 : A case study of quantum-classical correspondence journal July 1999
Reduced dimension rovibrational variational calculations of the S 1 state of C 2 H 2 . II. The S 1 rovibrational manifold and the effects of isomerization journal January 2014
Full dimensional Franck-Condon factors for the acetylene à 1 A u —X̃ Σg+1 transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene journal October 2014
New vibrational assignments in the Ā 1 A u -[Xtilde] 1 Σ + g electronic transition of acetylene, C 2 H 2 : the v′ 1 frequency journal February 2003
Direct observation of the symmetric stretching modes of à 1 A u acetylene by pulsed supersonic jet laser induced fluorescence journal August 2008
Anharmonic force fields of cis - and trans -S 1 C 2 H 2 journal July 2012
The à 1 A u state of acetylene: ungerade vibrational levels in the region 45,800–46,550 cm −1 journal July 2012
Spectroscopy and vibrational couplings in the 3v 3 region of acetylene journal February 1989
Investigations on the infrared spectrum of acetylene between 2500 cm -1 and 2800 cm -1 and studies of the resonance effects journal April 1992
The absorption spectrum of C 2 H 2 around ν 1 + ν 3 : energy standards in the 1.5 μm region and vibrational clustering journal November 1994
Rotation–Vibration Constants of Acetylene* journal January 1963

Cited By (4)

Photoelectron spectroscopy of boron-containing reactive intermediates using synchrotron radiation: BH 2 , BH, and BF journal January 2020
Toward spectroscopically accurate global ab initio potential energy surface for the acetylene-vinylidene isomerization journal December 2014
Generalized oscillator strengths of the low-lying valence-shell excitations of N 2 , O 2, and C 2 H 2 studied by fast electron and inelastic x-ray scattering journal March 2019
Fundamental mechanisms for molecular energy conversion and chemical reactions at surfaces journal August 2019

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