Half-projected Hartree-Fock calculations for the spectroscopic parameters, frequencies, and intensities of the torsional mode of the lowest lying singlet excited states of hydrogen peroxide

Mukherjee, P. K.; Senent, María Luisa; Smeyers, Yves G.

doi:10.1002/(sici)1097-461x(1999)75:4/5<631::aid-qua29>3.0.co;2-l

Cited by 4 publications

(4 citation statements)

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“…H 2 O 2 is one of the simplest molecules bearing two adjacent heteroatoms. As a small molecule important in biochemistry and in atmospheric chemistry, it naturally has received considerable attention, and several studies about the nature of its excited states have been published. − Experimental evidence from EPR measurements indicates that a “repulsive triplet state” plays a role in the photochemistry of hydrogen peroxide . Previous computational studies had focused on vertical excitation energies. − To the best of our knowledge, however, no detailed study has been published on the geometry of the lowest triplet excited state of H 2 O 2 at its relaxed geometry.…”

Section: Results and Discussionmentioning

confidence: 99%

(π,σ), (σ,π) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

Hill

Bucher

2014

J. Phys. Chem. A

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The properties of the lowest triplet excited states of a series of small molecules containing two or more adjacent heteroatoms have been investigated. High-level coupled cluster and MRCI+Q calculations were employed to probe the properties of the triplet excited states of hydrogen peroxide, hydrazine, hydroxylamine, fluoroamines, oxygen difluoride, hypofluorous acid, chlorine, fluorine, and disulfane. All of the molecules investigated except hydroxylamine are predicted to have bound lowest triplet excited states that are either (π*,σ*) or (σ*,π*) as in H2O2, HOF, OF2, H2S2, Cl2, NH2F, NHF2, or NF3, or are Rydberg states (hydrazine, also H2O2 and H2S2). The heteroatom-heteroatom bond dissociation enthalpies of the triplet states range from very small values as predicted for hydrogen peroxide or fluorine, to BDEs around 8-9 kcal mol(-1) that should allow for an experimental observation of the triplet state, such as in disulfane or monofluoroamine. For all triplet minima investigated except NF3 and F2, CCSD(T) gave results in agreement with the multireference method MRCI+Q, and in excellent agreement with available experimental data (BDEs, ground-state geometries). Due to multireference problems, CCSD(T) does not provide a good description for longer heteroatom-heteroatom distances, and in some cases (e.g., Cl2) it wrongly predicts the presence of a transition state for bond formation on the triplet spin manifold, where the reaction is known experimentally and, as predicted by MRCI+Q, is known to be barrierless. Finally, the (3)Π(u) state of F2 is poorly described by CCSD(T) theory, the equilibrium bond distance is significantly underestimated relative to MRCI+Q, and CCSD(T) places the triplet state above the energy of two fluorine atoms. The T1 diagnostic, frequently used to assess the quality of CCSD(T) calculations, does not appear to provide a valid criterion for the systems studied. The formation of H2O2 on the triplet potential energy hypersurface might possibly open up an additional channel for formation of hydrogen peroxide from two hydroxyl radicals. Due to a low density of states in triplet H2O2, and due to competing formation of water + O((3)P) from a hydrogen-bridged HO···HO triplet radical pair, such a reaction channel probably only can play a role at low temperatures.

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Section: Results and Discussionmentioning

confidence: 99%

(π,σ), (σ,π) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

Hill

Bucher

2014

J. Phys. Chem. A

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“…This particular region has to be subjected to more detailed studies. [ 22] methods. The geometries of the S 1 -A and S 2 -B excited states were also optimized using CASSCF and SAC-CI methods, also resulting in cis-and trans-planar structures.…”

Section: Vertical Excitation Energymentioning

confidence: 99%

“…The geometries of the S 1 -A and S 2 -B excited states were also optimized using CASSCF and SAC-CI methods, also resulting in cis-and trans-planar structures. The O-H bond distance and angle HOO of the S 1 -A and the S 2 -B excitated states predicted by CASSCF and SAC-CI are similar, and they are also similar to published CIS results [22]. The O-O bond distance of the S 1 -A and the S 2 -B excited states predicted by CASSCF and SAC-CI are similar, respectively, see table 1, but they are a little longer than the CIS predicted values, which are 1.263 Å for the S 1 -A state and 1.277 Å for the S 2 -B state [22].…”

Section: Vertical Excitation Energymentioning

confidence: 99%

“…A very recent photodissociation study at around 355 nm, using both linearly and circularly polarized light, indicated that the 1 A and 1 B states are the main states involved at 355 nm [19]. The excited states of H 2 O 2 have previously been studied by a number of authors [20][21][22][23]. However, in view of the new experimental information concerning the wavelength dependence of the photodissociation products, a more extensive theoretical investigation of the potential-energy surfaces (PESs) of hydrogen peroxide is called for.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical study of the photodissociation of low lying excited states of hydrogen peroxide

2004

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In order to explain recent photofragmentation experiments of hydrogen peroxide, the vertical excitation energies, potential-energy curves and surfaces, harmonic vibrational frequencies, and transition moments for a number of low lying excited states were calculated. The accessibility of different photodissociation channels for different excitation wavelengths was discussed, on the basis of the calculated results.

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NIST-JANAF Thermochemical Tables. II. Three Molecules Related to Atmospheric Chemistry: HNO3, H2SO4, and H2O2

Дорофеева

Iorish

Novikov

et al. 2003

Journal of Physical and Chemical Reference Data

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The structural, spectroscopic, and thermochemical properties of three polyatomic molecules with internal rotation—HNO3(g), H2SO4(g), and H2O2(g)—have been reviewed. Three revised ideal gas thermodynamic tables result from this critical examination. The revisions involved the consideration of new spectroscopic information and the use of theoretical results to model the internal rotation in the H2SO4 molecule. Compared to previous calculations, the entropies at 298.15 K are unchanged for HNO3 and H2O2, but the high temperature values (T>4000 K) are significantly different. As for H2SO4, its thermodynamic functions differ significantly from values calculated earlier.

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Half-projected Hartree-Fock calculations for the spectroscopic parameters, frequencies, and intensities of the torsional mode of the lowest lying singlet excited states of hydrogen peroxide

Cited by 4 publications

References 37 publications

(π,σ), (σ,π) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

(π,σ), (σ,π) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

Theoretical study of the photodissociation of low lying excited states of hydrogen peroxide

NIST-JANAF Thermochemical Tables. II. Three Molecules Related to Atmospheric Chemistry: HNO3, H2SO4, and H2O2

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Half-projected Hartree-Fock calculations for the spectroscopic parameters, frequencies, and intensities of the torsional mode of the lowest lying singlet excited states of hydrogen peroxide

Cited by 4 publications

References 37 publications

(π*,σ*), (σ*,π*) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

(π*,σ*), (σ*,π*) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

Theoretical study of the photodissociation of low lying excited states of hydrogen peroxide

NIST-JANAF Thermochemical Tables. II. Three Molecules Related to Atmospheric Chemistry: HNO3, H2SO4, and H2O2

Contact Info

Product

Resources

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(π,σ), (σ,π) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

(π,σ), (σ,π) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms