Photoisomerization dynamics of stilbenes

Waldeck, David H.

doi:10.1021/cr00003a007

Cited by 1,294 publications

(1,096 citation statements)

References 36 publications

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“…65 The mechanisms for the photodynamics and the locations of the conical intersections have been well characterized. There are three types of low-lying conical intersections: one-bond flip (OBF), hula-twist (HT), and 4a,4b-dihydrophenanthrene(DHP)-like conical intersections.…”

Section: Conical Intersections Of Stilbenementioning

confidence: 99%

Analytical Derivative Coupling for Multistate CASPT2 Theory

Park

Shiozaki

2017

J. Chem. Theory Comput.

139

169

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The probability of non-radiative transitions in photochemical dynamics is determined by the derivative couplings, the couplings between different electronic states through the nuclear degrees of freedom. Efficient and accurate evaluation of the derivative couplings is, therefore, of central importance to realize reliable computer simulations of photochemical reactions. In this work, the derivative couplings for multistate multireference second-order perturbation theory (MS-CASPT2) and its 'extended' variant (XMS-CASPT2) are studied, in which we present an algorithm for their analytical evaluation. The computational costs for evaluating the derivative couplings are essentially the same as those for calculating the nuclear energy gradients. The geometries and energies calculated with XMS-CASPT2 for small molecules at minimum energy conical intersections (MECIs) are in good agreement with those computed by multireference configuration interaction. As numerical examples, MECIs are optimized using XMS-CASPT2 for stilbene and a GFP model chromophore (the 4-para-hydroxybenzylidene-1,2-dimethyl-imidazolin-5-one anion).

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Section: Conical Intersections Of Stilbenementioning

confidence: 99%

Analytical Derivative Coupling for Multistate CASPT2 Theory

Park

Shiozaki

2017

J. Chem. Theory Comput.

139

169

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“…This assumption is certainly valid for synthetic molecular motors such as shown in Scheme 1. A quarter rotation, once the motor is excited, happens on the scale of tens of picoseconds (27,(39)(40)(41)(42), whereas the interval between two jumps (i.e., two quarter rotations) typically ranges from seconds to hours. Due to the huge ratio of both time scales (Ͼ10 10 ), we can safely conclude that in between two quarter rotations, a molecular motor will have lost its memory.…”

Section: Modeling the Evolution Of The Molecular Fractionsmentioning

confidence: 99%

Optimizing rotary processes in synthetic molecular motors

Geertsema

Molen

Martens

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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We deal with the issue of quantifying and optimizing the rotation dynamics of synthetic molecular motors. For this purpose, the continuous four-stage rotation behavior of a typical light-activated molecular motor was measured in detail. All reaction constants were determined empirically. Next, we developed a Markov model that describes the full motor dynamics mathematically. We derived expressions for a set of characteristic quantities, i.e., the average rate of quarter rotations or ''velocity,'' V, the spread in the average number of quarter rotations, D, and the dimensionless Pé clet number, Pe ‫؍‬ V/D. Furthermore, we determined the rate of full, four-step rotations (⍀ eff), from which we derived another dimensionless quantity, the ''rotational excess,'' r.e. This quantity, defined as the relative difference between total forward (⍀ ؉) and backward (⍀؊) full rotations, is a good measure of the unidirectionality of the rotation process. Our model provides a pragmatic tool to optimize motor performance. We demonstrate this by calculating V, D, Pe, ⍀ eff, and r.e. for different rates of thermal versus photochemical energy input. We find that for a given light intensity, an optimal temperature range exists in which the motor exhibits excellent efficiency and unidirectional behavior, above or below which motor performance decreases. Markov model ͉ unidirectional rotation

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“…It is a direct pro-drug activation without the need of the formation of a long-lived energy transferring triplet state and furthermore an oxygen-independent process. The photoisomerization process is reversible and depends on the wavelength used for excitation as it is commonly seen for stilbenes [123,124].…”

Section: Alternative Strategy For Two-photon Phototherapy (2p-pdt) Wimentioning

confidence: 99%

New Approaches to Photodynamic Therapy from Types I, II and III to Type IV Using One or More Photons

Scherer

Bisby²,

Botchway³

et al. 2017

ACAMC

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Photodynamic therapy (PDT) is an alternative cancer treatment to conventional surgery, radiotherapy and chemotherapy. It is based on activating a drug with light that triggers the generation of cytotoxic species that promote tumour cell killing. At present, PDT is mainly used in the treatment of wet age-related macular degeneration, for precancerous conditions of the skin (e.g. actinic keratosis) and in the palliative care of advanced cancers, for instance of the bladder or the oesophagus. Due to a lack of phase III clinical trials and limitations of light penetration to deeper lying tumours (in excess of 1 cm), PDT is still not used as a first line cancer treatment, which is surprising given the first clinical trials by Dougherty's group dating back to the 1970's. However research continues to demonstrate the potential benefits of PDT and the need to stimulate funding and uptake of clinical studies using next generation photosensitizers offering advanced targeted delivery, improved photodynamic dose combined with modern light delivery technologies. This review surveys the available PDT treatments and emerging novel developments in the field with a particular focus on two-photon techniques that are anticipated to improve the effectiveness of PDT in tissues at depth and on next generation drugs that work without the need of the presence of oxygen for photosensitization making them effective where hypoxia has taken hold.

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Photoisomerization dynamics of stilbenes

Cited by 1,294 publications

References 36 publications

Analytical Derivative Coupling for Multistate CASPT2 Theory

Analytical Derivative Coupling for Multistate CASPT2 Theory

Optimizing rotary processes in synthetic molecular motors

New Approaches to Photodynamic Therapy from Types I, II and III to Type IV Using One or More Photons

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