Theoretical prediction of spectroscopic constants of 1-alkoxy radicals

Tarczay, György; Gopalakrishnan, Sandhya; Miller, Terry A.

doi:10.1016/s0022-2852(03)00131-0

Cited by 34 publications

(58 citation statements)

References 56 publications

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“…We have further demonstrated that we were able to predict the observed spin-rotation constants using the isotopic substitution approach proposed by Brown, Sears, and Watson 37 and extended by Tarczay et al 49 The fact that we were able to obtain and analyze spectra from the higher energy T conformer leads to the conclusion that in our jet expansion, the conformers are not produced in thermal equilibrium. This work shows that observing and analyzing the spectra of even larger radicals are quite feasible.…”

Section: Discussionsupporting

confidence: 54%

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High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2

Just

Rupper

Miller

et al. 2009

The Journal of Chemical Physics

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We have recorded high resolution, partially rotationally resolved, jet-cooled cavity ringdown spectra of the origin band of the A-X electronic transition of both the G and T conformers of the perproteo and perdeutero isotopologues of the ethyl peroxy radical, C(2)H(5)O(2). This transition, located in the near infrared, was studied using a narrow band laser source (< or approximately 250 MHz) and a supersonic slit-jet expansion coupled with an electric discharge allowing us to obtain rotational temperatures of about 15 K. All four spectra have been successfully simulated using an evolutionary algorithm approach with a Hamiltonian including rotational and spin-rotational terms. Excellent agreement with the experimental spectra was obtained by fitting seven molecular parameters in each ground and the first excited electronic states as well as the band origin of the electronic transition. This analysis unambiguously confirms the assignment of the lower frequency origin band to the G conformer and the higher frequency one to the T conformer.

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Section: Discussionsupporting

confidence: 54%

“…Tarczay et al 49 extended this procedure to relate the components of the spin-rotation tensor for any molecule in the same family. The basic physical requirement for the Tarczay extension is that the electronic transition be localized on a given chromophore with common electronic structure for all the family members.…”

Section: ͑15͒mentioning

confidence: 99%

High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2

Just

Rupper

Miller

et al. 2009

The Journal of Chemical Physics

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“…The rotational Hamiltonian is expressed as the sum of purely rotational and spin-rotation terms: 41,42 …”

Section: B Electronic Spectroscopy: Rotationsmentioning

confidence: 99%

“…The spin-rotation parameter ε is determined by two factors. 41 For open-shell metal compounds, the dominant contribution is usually the second-order interaction between spin-orbit coupling and the Coriolis interaction. There is also some contribution from coupling of the electron spin to the magnetic field due to molecular rotation.…”

Section: 12mentioning

confidence: 99%

Near ultraviolet photodissociation spectroscopy of Mn+(H2O) and Mn+(D2O)

Pearson

Copeland

Kocak

et al. 2014

The Journal of Chemical Physics

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excited states with T 0 = 30 210 and 32 274 cm −1 , respectively. Each electronic transition has partially resolved rotational and extensive vibrational structure with an extended progression in the metal−ligand stretch at a frequency of ∼450 cm −1 . There are also progressions in the in-plane bend in the 7 B 2 state, due to vibronic coupling, and the out-of-plane bend in the 7 B 1 state, where the calculation illustrates that this state is slightly non-planar. Electronic structure computations at the CCSD(T)/aug-cc-pVTZ and TD-DFT B3LYP/6-311++G(3df,3pd) level are also used to characterize the ground and excited states, respectively. These calculations predict a ground state Mn-O bond length of 2.18 Å. Analysis of the experimentally observed vibrational intensities reveals that this bond length decreases by 0.15 ± 0.015 Å and 0.14 ± 0.01 Å in the excited states. The behavior is accounted for by the less repulsive p x and p y orbitals causing the Mn + to interact more strongly with water in the excited states than the ground state. The result is a decrease in the Mn-O bond length, along with an increase in the H-O-H angle. The spectra have well resolved K rotational structure. Fitting this structure gives spin-rotation constants ε aa = −3 ± 1 cm −1 for the ground state and ε aa = 0.5 ± 0.5 cm −1 and aa = −4.2 ± 0.7 cm −1 for the first and second excited states, respectively, and A = 12.8 ± 0.7 cm −1 for the first excited state. Vibrationally mediated photodissociation studies determine the O-H antisymmetric stretching frequency in the ground electronic state to be 3658 cm −1 .

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“…26 Only a brief summary will be given here. Rotational constants were determined by analytic geometry optimization at the B3LYP/6-31+G* and the CIS/6-31+G* levels for theX andB states respectively.…”

Section: Prediction Of Rotational and Spin-rotation Constantsmentioning

confidence: 99%

Rotationally Resolved Electronic Spectra of the B̃−X̃ Transition in Multiple Conformers of 1-Butoxy and 1-Pentoxy Radicals

Gopalakrishnan

Miller

2003

J. Phys. Chem. A

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We report the rotational analyses of 6 bands of theB −X electronic transition of jet cooled 1-butoxy radical and 11 bands of the corresponding transition in 1-pentoxy radical. From these spectra, we have obtained experimental values for the rotational and spin-rotational constants in theX state and the rotational constants, vibrational frequencies, and band origins in theB state. By comparing the rotational and spin-rotational constants from these analyses with corresponding values from quantum chemistry computations, we assign the observed spectra to the electronic origins and excited vibrational levels of theB state of 3 distinct conformers of 1-butoxy and 5 distinct conformers of 1-pentoxy. These assigned bands can be used as unambiguous diagnostics of the radical species, its structural isomer, and its conformation. This data can be used to identify, and to some extent rationalize, distinctively different conformer stabilities in theX andB states and conformer-dependent dynamical behavior.

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Theoretical prediction of spectroscopic constants of 1-alkoxy radicals

Cited by 34 publications

References 56 publications

High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2

High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2

Near ultraviolet photodissociation spectroscopy of Mn+(H2O) and Mn+(D2O)

Rotationally Resolved Electronic Spectra of the B̃−X̃ Transition in Multiple Conformers of 1-Butoxy and 1-Pentoxy Radicals

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