Electronic structure of dicarbonyls. Glyoxal excited states

Dykstra, Clifford E.; Schaefer, Henry F.

doi:10.1021/ja00418a014

Cited by 40 publications

(8 citation statements)

References 22 publications

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“…Large amount of energy lowering, 0.75 and 1.22 eV, due to geometry relaxation was also calculated for the 1 3 A g and 1 3 B u states, respectively. Similar trend was reported by the previous SAC-CI calculation 19 and CI calculations 20,61 for the 1 3 B u state. On the other hand, the energy lowering for the 1 1 B g states was small, although the geometry change was large.…”

Section: Ground-and Excited-state Geometries Of S-trans Glyoxalsupporting

confidence: 90%

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Singly and doubly excited states of butadiene, acrolein, and glyoxal: Geometries and electronic spectra

Saha

Ehara²,

Nakatsuji³

2006

The Journal of Chemical Physics

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Excited-state geometries and electronic spectra of butadiene, acrolein, and glyoxal have been investigated by the symmetry adapted cluster configuration interaction (SAC-CI) method in their s-trans conformation. Valence and Rydberg states below the ionization threshold have been precisely calculated with sufficiently flexible basis sets. Vertical and adiabatic excitation energies were well reproduced and the detailed assignments were given taking account of the second moments. The deviations of the vertical excitation energies from the experiment were less than 0.3 eV for all cases. The SAC-CI geometry optimization has been applied to some valence and Rydberg excited states of these molecules in the planar structure. The optimized ground- and excited-state geometries agree well with the available experimental values; deviations lie within 0.03 A and 0.7 degrees for the bond lengths and angles, respectively. The force acting on the nuclei caused by the excitations has been discussed in detail by calculating the SAC-CI electron density difference between the ground and excited states; the geometry relaxation was well interpreted with the electrostatic force theory. In Rydberg excitations, geometry changes were also noticed. Doubly excited states (so-called 2 (1)A(g) states) were investigated by the SAC-CI general-R method considering up to quadruple excitations. The characteristic geometrical changes and large energetic relaxations were predicted for these states.

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Section: Ground-and Excited-state Geometries Of S-trans Glyoxalsupporting

confidence: 90%

“…We got a value of 3.42 eV for the 1 3 AЉ state, corresponding available experimental value is 3.01 eV. 14 In the ⌬SCF calculation, 61 the energy obtained lowering for 1 3 AЈ and 1 3 AЉ states were as large as 1.11 and 0.68 eV, respectively.…”

Section: Ground-and Excited-state Geometries Of S-trans Acroleinmentioning

confidence: 72%

Singly and doubly excited states of butadiene, acrolein, and glyoxal: Geometries and electronic spectra

Saha

Ehara²,

Nakatsuji³

2006

The Journal of Chemical Physics

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“…45,73,74 These assignments agree with other experimental [75][76][77][78][79] and theoretical 35,80,81 studies. Dykstra and Schaefer 82 have predicted two low-lying ͑ϳ15 000 cm Ϫ1 ͒ unobserved triplet states from ab initio calculation. Because of high energies of excited electronic states of glyoxal, they are not considered in this work.…”

Section: Heat Capacity and Entropymentioning

confidence: 99%

NIST-JANAF Thermochemical Tables. I. Ten Organic Molecules Related to Atmospheric Chemistry

Дорофеева

Novikov

Neumann

2001

Journal of Physical and Chemical Reference Data

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The structural, spectroscopic, and thermodynamic properties of 10 gas phase organic molecules related to atmospheric chemistry, including three peroxides and four carboxylic acids, are reviewed. The calculation of the thermochemical tables involved the critical evaluation of new spectroscopic data, enthalpy of formation determinations, and the use of recent internal rotation data. Since insufficient information to characterize all 10 molecules exists, estimation schemes were used to provide the missing experimental and theoretical data.

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“…Additionally, the S 1 NTII intrinsic reaction barrier for 2-oxobutanal is higher than the T 1 energy, but this may be due to the different electronic nature of α-dicarbonyls. 75,76 Thus, comparison of the S 1 TD-B2GP-PLYP and T 1 UB2GP-PLYP energies in Figure 2 does not indicate, in itself, a failure of the TD-DFT method.…”

Section: Comparison Between S 1 and T 1 B2gp-plyp Energiesmentioning

confidence: 90%

Structural Causes of Singlet/triplet Preferences of Norrish Type II Reactions in Carbonyls

Rowell

Kable²,

Jordan³

2020

Preprint

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Photolysis thresholds are calculated for the Norrish Type II (NTII) intramolecular γ-hydrogen abstraction reaction in 22 structurally informative carbonyl species. The B2GP-PLYP excited state S1 and T1 thresholds agree well with triplet quenching experiments. However, many linear-response methods deliver poor S1 energetics, which is explained by a S1/S0 conical intersection in close proximity to the S1 transition state. Multiconfigurational CASSCF calculations confirm a conical intersection features across all carbonyl classes. <div> </div><div>Structure–activity relationships are determined that could be used in atmospheric carbonyl photochemsitry modelling. This is exemplified for butanal, whose NTII quantum yields are too low when used as a ‘surrogate’ for larger carbonyls, since butanal lacks the γ-substitution that stabilises the 1,4- biradical. Reaction on T1 dominates only in species where the S1 thresholds are high — typically ketones. The α, β-unsaturated carbonyls cannot cleave the α–β bond, causing them to photoisomerise. A concerted S0 NTII mechanism is calculated to be viable and may explain the recent detection of NTII photoproducts in the photolysis of pentan-2-one below the T1 threshold.</div>

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Electronic structure of dicarbonyls. Glyoxal excited states

Cited by 40 publications

References 22 publications

Singly and doubly excited states of butadiene, acrolein, and glyoxal: Geometries and electronic spectra

Singly and doubly excited states of butadiene, acrolein, and glyoxal: Geometries and electronic spectra

NIST-JANAF Thermochemical Tables. I. Ten Organic Molecules Related to Atmospheric Chemistry

Structural Causes of Singlet/triplet Preferences of Norrish Type II Reactions in Carbonyls

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