Photodimerization of 2,6-diphenylpyrylium salt in the solution

Kawata, Hiroki; Suzuki, Yoshizo; Niizuma, Shigeya

doi:10.1016/s0040-4039(00)84986-2

Cited by 20 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…is near the diffusion limit and is almost equal to that which could be estimated by nanosecond flash-photolysis techniques (15). This value of k dim represents a half-life of ~200 ns for pyrylium radical.…”

Section: Kinetic Applicationssupporting

confidence: 49%

When Voltammetry Reaches Nanoseconds

Amatore

Maisonhaute²

2005

Anal. Chem.

101

View full text Add to dashboard Cite

Section: Kinetic Applicationssupporting

confidence: 49%

When Voltammetry Reaches Nanoseconds

Amatore

Maisonhaute²

2005

Anal. Chem.

101

View full text Add to dashboard Cite

“…Evidence for the pyranyl radical could only be obtained using time-resolved spectroscopy. 63 Likewise, when using TPT as photosensitizer in the presence of electron donors, a second piece of evidence for the operation of a PET mechanism has been received by the detection in some cases of TP* using time- F. Lack of Singlet Oxygen Formation TPT is not able to participate in energy transfer from its excited triplet state to ground-state oxygen, at least under the usual photooxygenation conditions.36,64…”

Section: E Photolytic Generation Of Pyranyl Radicalsmentioning

confidence: 99%

2,4,6-Triphenylpyrylium Tetrafluoroborate as an Electron-Transfer Photosensitizer

Miranda¹,

García²

1994

Chem. Rev.

340

248

View full text Add to dashboard Cite

“…While 1a was able to achieve temporal control, at high conversions we started to observe some monomer conversion in the dark. This, in part, is due to pyrylium catalyst decomposition ,− and can be mitigated by switching to more stable photocatalysts. For this reason, we investigated polypyridyl Ir complexes, which have been extensively used as catalysts in small-molecule transformations.…”

Section: Photocontrolled Cationic Raftmentioning

confidence: 99%

Photoredox Catalysis in Photocontrolled Cationic Polymerizations of Vinyl Ethers

Sifri

Fors

2022

Acc. Chem. Res.

View full text Add to dashboard Cite

Metrics & MoreArticle Recommendations CONSPECTUS: Advances in photocontrolled polymerizations have expanded the scope of polymer architectures and structures that can be synthesized for various applications. The majority of these polymerizations have been developed for radical processes, which limits the diversity of monomers that can be used in macromolecular design. More recent developments of photocontrolled cationic polymerizations have taken a step toward addressing this limitation and have expanded the palette of monomers that can be used in stimuli-regulated polymerizations, enabling the synthesis of previously inaccessible polymeric structures. This Account will detail our group's studies on cationic polymerization processes where chain growth is regulated by light and highlight how these methods can be combined with other stimuli-controlled polymerizations to precisely dictate macromolecular structure. Photoinitiated cationic polymerizations are well-studied and important processes that have control over initiation. However, we wanted to develop systems where we had spatiotemporal control over both polymer initiation and chain growth. This additional command over the reaction provides the ability to manipulate the growing polymer with an external stimulus during a polymerization, which can be used to control structure. To achieve this goal, we set out to develop a method to photoreversibly generate a cation at a growing chain end that could participate in a controlled polymerization process. We took inspiration from previous work on cationic degenerate chain transfer polymerizations of vinyl ethers that used thiocarbonylthio chain transfer agents. These polymerizations were initiated by a strong acid and gave well-defined poly(vinyl ether)s. We posited that we could remove the acid initiator in these systems and reversibly oxidize the thiocarbonylthio chain ends in these reactions with a photocatalyst to give a photocontrolled cationic polymerization of vinyl ethers. This Account will focus on our journey to discover cationic photocontrolled polymerizations. We will summarize our initial developments and detail our mechanistic understanding of these reactions using both organic and inorganic based photocatalysts, and we will outline more recent efforts to expand cationic degenerate chain transfer polymerizations to other thioacetal initiators. Finally, we will detail how these photocontrolled cationic polymerizations can be used to switch monomer selectivity in situ using light to control polymer structure. At the end of the Account, we will discuss our vision for future potential applications of these photocontrolled cationic polymerizations in the synthesis of novel block copolymers and next generation cross-linked networks.

show abstract

Photodimerization of 2,6-diphenylpyrylium salt in the solution

Cited by 20 publications

References 2 publications

When Voltammetry Reaches Nanoseconds

When Voltammetry Reaches Nanoseconds

2,4,6-Triphenylpyrylium Tetrafluoroborate as an Electron-Transfer Photosensitizer

Photoredox Catalysis in Photocontrolled Cationic Polymerizations of Vinyl Ethers

Contact Info

Product

Resources

About