The role of nonadiabatic coupling and sudden polarization in the photoisomerization of olefins

Persico, Maurizio

doi:10.1021/ja00547a002

Cited by 33 publications

(13 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These calculations were focused on the torsional coordinate, the crossings of V and Z PE functions for torsional angles near 90°, and the sudden-polarization effect, as well as on crossings of the V state with the 3p Rydberg states. 11,12 Onedimensional torsional PE functions of the N, V, Z states have also been determined by Persico 38 and Dormans et al 39 More recently, three-dimensional PE surfaces have been obtained by Groenenboom at the multireference CEPA level as a function of torsion, C-C stretch, and the symmetric scissors coordinate. 12 Ben-Nun and Martínez 1 and Molina et al 40 have characterized in more detail the conical intersections between the N, V, and Z states with the MRCI and CASPT2 method, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…It should be mentioned that RR spectra of the V state 9,10 have been simulated by Siebrand, Zgierski and co-workers within three-dimensional models. 48,49 The first time-dependent wave packet studies of the photochemistry of ethene have been performed by Persico 38 and Dormans et al 39 within one-dimensional models ͑torsion only͒. It is clear from the above-discussed electronicstructure calculations on the qualitative shape of the PE surfaces of ethene that at least the torsion, the C-C stretch motion, and the pyramidalization have to be included in the description of the photochemical dynamics.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Photoinduced dynamics of the valence states of ethene: A six-dimensional potential-energy surface of three electronic states with several conical intersections

Krawczyk

Viel

Manthe

et al. 2003

The Journal of Chemical Physics

View full text Add to dashboard Cite

A six-dimensional analytic potential-energy surface of the three valence states (N, V, Z) of ethene has been constructed on the basis of complete-active-space ab initio calculations and ab initio calculations with perturbation theory of second order based on a complete active reference space. The nuclear coordinate space is spanned by the torsion, the C-C stretch coordinate, the left and right pyramidalization and the symmetric and antisymmetric scissor coordinates. The C-H stretch coordinates and the CH 2 rocking angles are kept frozen at their ground-state equilibrium value. A diabatic representation of the valence states of ethene has been constructed within the framework of a Hückel-type model. The diabatic potential-energy elements are represented as analytic functions of the relevant coordinates. The parameters of the analytic functions have been determined by a least-squares fit of the eigenvalues of the diabatic potential-energy matrix to the ab initio data for one-dimensional and two-dimensional cuts of the six-dimensional surface. As a function of the torsion, the analytic potential-energy surface describes the intersections of the V and Z states for torsional angles near 90°, which are converted into conical intersections by the antisymmetric scissor mode. As a function of pyramidalization of perpendicular ethene, it describes the intersections of the diabatic N and Z states, which are converted into conical intersections by displacements in the torsional mode. The analytic potential-energy surfaces can provide the basis for a quantum wave packet description of the internal conversion of photoexcited ethene to the electronic ground state via conical intersections.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Photoinduced dynamics of the valence states of ethene: A six-dimensional potential-energy surface of three electronic states with several conical intersections

Krawczyk

Viel

Manthe

et al. 2003

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…4͒ are strongly stabilized by the torsion and are nearly degenerate at a torsional angle of 90°. However, the energy gap of 2.4 eV to the ground state is too large and the nonadiabatic couplings are too small 5,6 to explain, for example, the measurement of the ultrafast decay of the V͑S 1 ͒ state. [7][8][9][10] In the search for the intersection of the V state with the ground state-a major feature governing the photodynamics of ethylene-significant progress was made by the work of Ohmine 11 who pointed out the importance of a hydrogen migration process for this intersection.…”

Section: Introductionmentioning

confidence: 99%

“…During a long period of time, the investigation of the pyramidalization process was focused almost exclusively on the aforementioned sudden polarization effect. In these investigations, the pyramidalization up to an angle of only 70°was investigated, 5 which is too small to reach the S 1 / S 0 crossing occurring at around 95°in a rigid pyramidalization. 12 Only in 1998, Freund and Klessinger, 13 and independently Ben-Nun and Martinez 14 pointed out that pyramidalization should play an important role in the photochemistry of ethylene.…”

Section: Introductionmentioning

confidence: 99%

The photodynamics of ethylene: A surface-hopping study on structural aspects

Barbatti

Ruckenbauer

Lischka

2005

The Journal of Chemical Physics

View full text Add to dashboard Cite

Simulations of the photodynamics of ethylene were carried out by employing the semiempirical direct trajectory with surface hopping method in order to assess quantitatively the importance of different regions of the S(2)S(1) and S(1)S(0) crossing seams. The results show that during the first 50 fs after a vertical photoexcitation to the pipi(*) state, the nonadiabatic coupling between the S(1) and the S(2) states produces a recurrence pattern of oscillation of the populations in these states. Within the first 100 fs, the S(1) state population spans a limited region of the configuration space between the initial geometries and the twisted-pyramidalized minimum on the crossing seam (MXS). Depending on the way of counting, about 50% of the S(1)-->S(0) transitions occur in the pyramidalized region of the crossing seam, but not necessarily close to the MXS. The remaining 50% occurs in the H-migration and ethylidene regions. Our analysis shows that the ethylidene region becomes more important in later stages of the dynamics when the flux of trajectories that was not effectively converted to the ground state in the pyramidalized region starts to reach this part of the configuration space. The excited-state nonadiabatic dynamics could be employed to generate suitable initial phase space distributions for the hot-ethylene ground-state kinetic studies.

show abstract

“…By using eqs. ( 27) and (28) one can obtain the follow ing expression for the ground state ψ 0 , from eqs. (A.12)and(A.l):…”

Section: χ=(ψ μ \η\ψ ν )/((ψ μ \η\* μ )mentioning

confidence: 99%

Etude Analytique De l'INTERACTION De Deux Centres Radicalaires. Application Auxpolyenes

Καραφιλογλου¹

View full text Add to dashboard Cite

The sudden polarization effectiis studied for a series of dodccahcxaiies. Results of minimal basis set ab initio calculations, followed by limitée configuration interaction, are presented. The observed tendencies are rationalized and an analytical formula is demonstrated, allowing calculation of the polarization for any twisted polyene as a function of the energy gap between its non-bonding orbitali and their derealization. Simple rules are presented which predict the existence, and the sign, of the sudden polarization effect for any non-substituted twisted olefin.

show abstract

The role of nonadiabatic coupling and sudden polarization in the photoisomerization of olefins

Cited by 33 publications

References 14 publications

Photoinduced dynamics of the valence states of ethene: A six-dimensional potential-energy surface of three electronic states with several conical intersections

Photoinduced dynamics of the valence states of ethene: A six-dimensional potential-energy surface of three electronic states with several conical intersections

The photodynamics of ethylene: A surface-hopping study on structural aspects

Etude Analytique De l'INTERACTION De Deux Centres Radicalaires. Application Auxpolyenes

Contact Info

Product

Resources

About