Benchmarking the Molecular Mechanics−Valence Bond Method:  Photophysics of Styrene and Indene

Bearpark, Michael J.; Bernardi, Fernando; Olivucci, Massimo; Robb, Michael A.

doi:10.1021/jp971733h

Cited by 38 publications

(36 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[25] Moreover, high level computational studies have simulated the potential energy curve of the excited state looking for conical intersections between S 1 and S 0 to account for the non-radiative processes of indene. [26] They found that the main mechanism involved is a fast and efficient internal conversion process. Therefore, the linkage of indene to BODIPY, via a vinyl group, results in a negative effect on the fluorescence capacity of the BODIPY chromophore, owing, probably, to the internal conversion of the indene group.…”

Section: Fluorene-bodipy Derivativesmentioning

confidence: 99%

Controlling Optical Properties and Function of BODIPY by Using Asymmetric Substitution Effects

Bañuelos¹,

Agarrabeitia²,

García‐Moreno³

et al. 2010

Chemistry A European J

View full text Add to dashboard Cite

Asymmetrically substituted BODIPY analogues of the dye PM567 have been synthesised from 2-acylpyrroles and pyrroles that bear indene, fluorene or difluorene units. The type of linkage between the fluorene and the BODIPY core plays an important role in the photophysics of the BODIPY chromophore. Indeed, an aliphatic bridge gives rise to an energy-transfer process between the chromophores, whereas a vinyl spacer allows an electronic interaction between them, leading to a large red shift of the spectral bands. The laser action of the new dyes has been analysed under transversal pumping at 10 Hz repetition rate, in both liquid phase and incorporated into solid polymeric matrices. Lasing efficiencies of up to 40% were reached with high photostabilities with the laser output remaining at the initial level after 1×10(5) pump pulses in the same position of the sample. The laser action of the new dyes outperforms the laser behaviour of commercial dyes that emit in the same spectral region. The replacement of fluorene by indene quenches the fluorescence and laser emission, but allows the development of an iron cation fluorescent sensor.

show abstract

Section: Fluorene-bodipy Derivativesmentioning

confidence: 99%

Controlling Optical Properties and Function of BODIPY by Using Asymmetric Substitution Effects

Bañuelos¹,

Agarrabeitia²,

García‐Moreno³

et al. 2010

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…1 Over many years, we have been able to understand the structures of model conical intersections using these methods. [54][55][56][57][58] In general, VB methods use a wavefunction that is a product of spin-coupled pairs defined in Eqn (3.1). [51][52][53] A full analysis of the cases of 3 electrons with 3 orbitals and 4 electrons with 4 orbitals has been given by Vanni et al 3 The 6 orbitals with 6 electrons problem has been analyzed by Blancafort et al 4 As we have discussed, we shall begin with situations where the wavefunction is dominated by "covalent" configurations, and the "ionic" configurations play no role.…”

Section: Introduction To Qualitative Vb Theorymentioning

confidence: 99%

In This Molecule There Must Be a Conical Intersection

Robb¹

2014

Advances in Physical Organic Chemistry

Self Cite

View full text Add to dashboard Cite

“…However, the natural orbital occupations at the CAS12 D2h structures (given in table 1) suggest that a correct zero-order description of So and S1 in D2h symmetry can be obtained by using an active space smaller than the full 12n orbital set. The smallest space which could describe both states simul- In a recent study, MMVB and CASSCF results were compared for the ground and valence excited states of styrene [41]. For planar structures, the relative energies were found to be within f 1 0 % of each other, and the ordering of states was the same.…”

Section: Methodsmentioning

confidence: 99%

Characterization of the indacene S0/S1 conical intersection: An MMVB and CASSCF study

et al. 1999

Self Cite

View full text Add to dashboard Cite

A conical intersection between the So and SI states of s-indacene has been located with the molecular mechanics with valence bond (MMVB) and complete active space SCF (CASSCF) methods. In both cases the intersection minimum is close in energy and geometry to the overall minimum on the S1 surface, and can be reached directly along the coordinate which leads from the Franck-Condon geometry to the minimum on S1. The existence of such an accessible SI/So surface crossing leading to efficient non-radiative decay can explain the short S, excited state lifetime and lack of fluorescence for s-indacene. Based on a comparison with X-ray structures for a derivative of s-indacene, we argue that the CASSCF ordering of So and SI states is the correct one, whereas MMVB inverts the two states. However, because the energy differences involved are a few kcal mol-', a definitive prediction will probably require a multireference correlated level of theory with gradient optimization.

show abstract

Benchmarking the Molecular Mechanics−Valence Bond Method: Photophysics of Styrene and Indene

Abstract: We have recently studied the excited states of the simplest aryl olefin styrene (Bearpark, M.

Cited by 38 publications

References 78 publications

Controlling Optical Properties and Function of BODIPY by Using Asymmetric Substitution Effects

Controlling Optical Properties and Function of BODIPY by Using Asymmetric Substitution Effects

In This Molecule There Must Be a Conical Intersection

Characterization of the indacene S0/S1 conical intersection: An MMVB and CASSCF study

Contact Info

Product

Resources

About