Uv photoelectron studies of biological pyrimidines: The electronic structure of uracil

Padva, A.; Lebreton, Pierre; Dinerstein, Robert J.; Ridyard, J. N. A.

doi:10.1016/0006-291x(74)90334-9

Cited by 55 publications

(23 citation statements)

References 14 publications

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“…A more extensive analysis of the higher occupied molecular orbitals of uracil will be published in the future. The high correlation of our data with experimental ionization potentials and the agreement of our assignments with prior theoretical ab-initio MO studies [22,23] on thymine point to the need for more experimental studies and more rigorous calculations before absolute assignments of cr or R character can be made to the second and third highest ionization potentials of uracil. …”

Section: A Electronic Structure Of Uracilsupporting

confidence: 76%

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Ab-initio sto-3G energy of tautomerism for uracil

Zielinski

Shibata

Rein

2009

Int. J. Quantum Chem.

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Ab-initio STO-3G energies for uracil (U) and the tautomer 4-hydroxyuracil (U*) are reported. The four highest occupied molecular orbital energies for uracil correlate with experimental photoelectron ionization potentials with a least-squares linear correlation coefficient of 0.999. The energy AE, for U * U* using the best available geometries is 25.5 kcal/mole. The reaction field continuum model for the solvent effect indicates that AE, may be lowered by approximately 3 kcal/mole. Therefore thediketo form of uracil is theoretically determined to be. the most stable form in solution as well as in the gas phase, in complete agreement with experiment.

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Section: A Electronic Structure Of Uracilsupporting

confidence: 76%

“…This result differs from other theoretical but less rigorous calculations which describe 28 as cr and 27 as R [21,22]. Experimental photoelectron spectroscopic studies on ureas, uracils, and thymine using naive MO diagrams also assign 28 as cr and 27 as ?r [20].…”

Section: A Electronic Structure Of Uracilcontrasting

confidence: 54%

Ab-initio sto-3G energy of tautomerism for uracil

Zielinski

Shibata

Rein

2009

Int. J. Quantum Chem.

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“…The first vertical IP at the EOM-IP-CCSD level of theory is 9.42 eV compared to the experimental 9.59 eV. 21 The IPs to the higher states D 1 , D 2 , and D 3 are 10.11 (10.11), 10.48 (10.56), and 11.08 (11.16) eV, respectively, with the experimental values given in parentheses. The errors between the experimental and theoretical IPs are between 0.00 and 0.17 eV.…”

Section: ■ Results and Discussionmentioning

confidence: 98%

Photoelectron Spectrum and Dynamics of the Uracil Cation

2015

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The photoelectron spectrum of uracil and the molecular dynamics of its radical cation are investigated using the multiconfigurational time-dependent Hartree (MCTDH) method. For this aim, the vibronic coupling model Hamiltonian is used including up to ten important a' modes. Moreover, to account for coupling through conical intersections between states of different symmetry in the system, coupling constants of two a″ modes are taken into account. The parameters used in the model are obtained by fitting to ab inito data obtained with extensive EOM-IP-CCSD calculations. The first four cationic states were investigated, which are either of A″ (hole in a π orbital) or A' (hole in a nO orbital) symmetry. The results of the wavepacket propagations were used to calculate the corresponding photoelectron spectrum and compare to the experimental spectrum. The MCTDH simulations reproduce the experimental spectrum well. The dynamics starting from the D2 and D3 ionic states show a fast relaxation to the cationic ground state often involving direct D2-D0 or D3-D1 transitions.

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“…This latter range is mainly cõrrelated to «--«* transitions of higher energies. Moreover, art increasing amount of ionization of s-electrons and at higher photon energies of «-electrons takes place as shown by measurements of ionization potentials of the bases [6,9].…”

Section: Resultsmentioning

confidence: 98%

Absorption of DNA in the region of vacuum-uv (3?25 eV)

Sontag

Weibezahn

1975

Radiat Environ Biophys

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By means of a device that might be considered a modern version of "Ulbricht's sphere" the absorption spectrum and the photoelectric emission of calf thymus DNA was measured in the region of 3 to 25 eV (400 to 50 nm). A tentative explanation of the general shape of the absorption spectrum and of its 6 maxima is given. The results permit a much better insight into some biologic effects of vacuum-uv to be gained than hitherto possible.

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Uv photoelectron studies of biological pyrimidines: The electronic structure of uracil

Cited by 55 publications

References 14 publications

Ab-initio sto-3G energy of tautomerism for uracil

Ab-initio sto-3G energy of tautomerism for uracil

Photoelectron Spectrum and Dynamics of the Uracil Cation

Absorption of DNA in the region of vacuum-uv (3?25 eV)

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