Access to the Triplet Excited States of Heavy-Atom-Free Boron-Dipyrromethene Photosensitizers via Radical Pair Intersystem Crossing for Image-Guided Tumor-Targeted Photodynamic Therapy

2021 ◽  
Vol 33 (19) ◽  
pp. 7889-7896
Author(s):  
Van-Nghia Nguyen ◽  
Jeongsun Ha ◽  
Chang Woo Koh ◽  
Bokyeong Ryu ◽  
Gyoungmi Kim ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Excited States ◽  
Radical Pair ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Image Guided ◽  
Boron Dipyrromethene ◽  
Targeted Photodynamic Therapy ◽  
Triplet Excited States

scholarly journals Intersystem Crossing of Radical Pair in Solvent Cage. External Heavy Atom Effect on Dual Photoreactions of Phthalazine

1991 ◽  
Vol 64 (11) ◽  
pp. 3340-3344 ◽  
Author(s):  
Hiroyasu Inoue ◽  
Tadamitsu Sakurai ◽  
Toshihiko Hoshi ◽  
Jun Okubo ◽  
Isao Ono
Keyword(s):  
Radical Pair ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Heavy Atom Effect ◽  
Solvent Cage ◽  
Atom Effect

Femtosecond Intersystem Crossing to the Reactive Triplet State of the 2,6-Dithiopurine Skin Cancer Photosensitizer

2021 ◽  
Author(s):  
Luis A. Ortiz-Rodríguez ◽  
Sean J. Hoehn ◽  
Chris Acquah ◽  
Nadia Abbass ◽  
Lidia Waidmann ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Skin Cancer ◽  
Triplet State ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Strong Absorption ◽  
Intersystem Crossing ◽  
Ultraviolet A

Site-selected sulfur-substituted nucleobases are a class of all organic, heavy-atom-free photosensitizers for photodynamic therapy applications that exhibit excellent photophysical properties such as strong absorption in the ultraviolet-A region of the...

scholarly journals An Optical Power Limiting and Ultrafast Photophysics Investigation of a Series of Multi-Branched Heavy Atom Substituted Fluorene Molecules

Inorganics ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 126 ◽  
Author(s):  
Hampus Lundén ◽  
Delphine Pitrat ◽  
Jean-Christophe Mulatier ◽  
Cyrille Monnereau ◽  
Iulia Minda ◽  
...  
Keyword(s):  
Organic Molecule ◽  
Molecular Design ◽  
Heavy Atom ◽  
Excited State Absorption ◽  
Optical Power ◽  
Intersystem Crossing ◽  
Design Paradigm ◽  
Probe Spectroscopy ◽  
Triplet Excited States ◽  
Optical Power Limiting

A common molecular design paradigm for optical power limiting (OPL) applications is to introduce heavy atoms that promote intersystem crossing and triplet excited states. In order to investigate this effect, three multi-branched fluorene molecules were prepared where the central moiety was either an organic benzene unit, para-dibromobenzene, or a platinum(II)–alkynyl unit. All three molecules showed good nanosecond OPL performance in solution. However, only the dibromobenzene and Pt–alkynyl compounds showed strong microsecond triplet excited state absorption (ESA). To investigate the photophysical cause of the OPL, especially for the fully organic molecule, photokinetic measurements including ultrafast pump–probe spectroscopy were performed. At nanosecond timescales, the ESA of the organic molecule was larger than the two with intersystem crossing (ISC) promoters, explaining its good OPL performance. This points to a design strategy where the singlet-state ESA is balanced with the ISC rate to increase OPL performance at the beginning of a nanosecond pulse.

External Heavy Atom Effect on Intersystem Crossing of Radical Pair in Solvent Cage. Photoreactions of Phthalazine

1990 ◽  
Vol 19 (7) ◽  
pp. 1059-1062
Author(s):  
Hiroyasu Inoue ◽  
Tadamitsu Sakurai ◽  
Toshihiko Hoshi ◽  
Jun Okubo ◽  
Isao Ono
Keyword(s):  
Radical Pair ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Heavy Atom Effect ◽  
Solvent Cage ◽  
Atom Effect

scholarly journals Barrier-free reverse-intersystem crossing in organic molecules by strong light-matter coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Suman Mallick ◽  
Mao Wang ◽  
Karl Börjesson
Keyword(s):  
Excited States ◽  
Light Emitting Diodes ◽  
Intersystem Crossing ◽  
Strong Light ◽  
Light Emitting ◽  
Matter Coupling ◽  
Hund’S Rule ◽  
Electrically Pumped ◽  
Triplet Excited States ◽  
Hund's Rule

AbstractStrong light-matter coupling provides the means to challenge the traditional rules of chemistry. In particular, an energy inversion of singlet and triplet excited states would be fundamentally remarkable since it would violate the classical Hund’s rule. An organic chromophore possessing a lower singlet excited state can effectively harvest the dark triplet states, thus enabling 100% internal quantum efficiency in electrically pumped light-emitting diodes and lasers. Here we demonstrate unambiguously an inversion of singlet and triplet excited states of a prototype molecule by strong coupling to an optical cavity. The inversion not only implies that the polaritonic state lies at a lower energy, but also a direct energy pathway between the triplet and polaritonic states is opened. The intrinsic photophysics of reversed-intersystem crossing are thereby completely overturned from an endothermic process to an exothermic one. By doing so, we show that it is possible to break the limit of Hund’s rule and manipulate the energy flow in molecular systems by strong light-matter coupling. Our results will directly promote the development of organic light-emitting diodes based on reversed-intersystem crossing. Moreover, we anticipate that it provides the pathway to the creation of electrically pumped polaritonic lasers in organic systems.

scholarly journals Barrier-Free Reverse-Intersystem Crossing by Strong Light-Matter Coupling

2020 ◽  
Author(s):  
Yi YU ◽  
Suman Mallick ◽  
Mao Wang ◽  
Karl Börjesson
Keyword(s):  
Excited States ◽  
Light Emitting Diodes ◽  
Intersystem Crossing ◽  
Strong Light ◽  
Light Emitting ◽  
Matter Coupling ◽  
Hund’S Rule ◽  
Electrically Pumped ◽  
Triplet Excited States ◽  
Hund's Rule

Strong light-matter coupling provides the means to challenge the traditional rules of chemistry. In particular, an energy inversion of singlet and triplet excited states would be fundamentally remarkable since it would violate the classical Hund’s rule. An organic chromophore possessing a lower singlet excited state can effectively harvest the “dark” triplet states, thus enabling 100% internal quantum efficiency in electrically pumped light-emitting diodes and lasers. Here we demonstrate unambiguously an inversion of singlet and triplet excited states of a prototype molecule by strong coupling to an optical cavity. The inversion not only implies that the polaritonic state lies at a lower energy, but also a direct energy pathway between the triplet and polaritonic states is opened. The intrinsic photophysics of reversed-intersystem crossing are thereby completely overturned from an endothermic process to an exothermic one. By doing so, we show that it is possible to break the limit of Hund’s rule and manipulate the energy flow in molecular systems by strong light-matter coupling. Our results will directly promote the development of organic light-emitting diodes based on reversed-intersystem crossing. Moreover, we anticipate that it provides the pathway to the creation of electrically pumped polaritonic lasers in organic systems.

scholarly journals Orthogonally Aligned Cyclic BODIPY Arrays with Long-lived Triplet Excited States as Efficient Heavy-Atom-Free Photosensitizers

2021 ◽  
Author(s):  
Zhaoyang Zhu ◽  
Xue Zhang ◽  
Xing Guo ◽  
Qing-Hua Wu ◽  
Zhongxin Li ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Excited State ◽  
Excited States ◽  
Heavy Atom ◽  
Triplet Excited State ◽  
Transfer Processes ◽  
Excited State Lifetimes ◽  
Triplet Excited States

Photosensitizers with long triplet excited state lifetimes are key to their efficient electron transfer or energy transfer processes. Herein, we report a novel class of cyclic trimeric BODIPY arrays which...

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