Results 61 to 70 of about 23,840 (266)

Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells

Beilstein Journal of Organic Chemistry, 2019
Novel caged nitroxides (nitroxide donors) with near-infrared two-photon (TP) responsive character, 2,2,6,6-tetramethyl-1-(1-(2-(4-nitrophenyl)benzofuran-6-yl)ethoxy)piperidine (2a) and its regioisomer 2b, were designed and synthesized. The one-photon (OP)
Ayato Yamada, Manabu Abe, Yoshinobu Nishimura, Shoji Ishizaka, Masashi Namba, Taku Nakashima, Kiyofumi Shimoji, Noboru Hattori   +7 more
doaj   +1 more source

Double Thionation of 4‐Dimethylaminophthalimide Leads to the Development of a Highly Effective Photosensitizer

Chemistry – A European Journal, EarlyView.
We report on the photophysical properties and electronic relaxation mechanisms of 4‐dimethylaminophthalimide (DMAP) and thio‐4‐dimethylaminophthalimide (SDMAP). While DMAP is fluorescent, SDMAP shows negligible fluorescence due to ultrafast intersystem crossing to a long‐lived triplet state that decays in 3.4 ± 0.05 µs.
Chris Acquah, Eric Lee, Sourav Kanti Seth, Reshma Mathew, Rubej R. Khan, Steffen Jockusch, Shudan Yang, Han Xiao, Carlos E. Crespo‐Hernández   +8 more
wiley   +1 more source

High-spin intermediates of the photolysis of 2,4,6-triazido-3-chloro-5-fluoropyridine

Beilstein Journal of Organic Chemistry, 2013
In contrast to theoretical expectations, the photolysis of 2,4,6-triazido-3-chloro-5-fluoropyridine in argon at 5 K gives rise to EPR peaks of just two triplet mononitrenes, two quintet dinitrenes, and a septet trinitrene.
Sergei V. Chapyshev, Denis V. Korchagin, Patrik Neuhaus, Wolfram Sander   +3 more
doaj   +1 more source

photolysis

, 2014
Citation: 'photolysis' in the IUPAC Compendium of Chemical Terminology, 3rd ed.; International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351/goldbook.P04624 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms.
openaire   +1 more source

The Role of Iron‐Hyponitrite Intermediates in Biology and Insights From Synthetic Model Complexes

Chemistry – A European Journal, EarlyView.
Despite the difference in active site architecture, NO reduction by different NOR enzymes is expected to be linked by a common intermediate: hyponitrite (N2O22−). However, experimentally, very little is known about the coordination chemistry of iron with hyponitrite and the expected Fe‐hyponitrite intermediates.
Michael O. Lengel, Nicolai Lehnert
wiley   +1 more source

Photosensitizing Au(I) Catalysis With Coumarins

Chemistry – A European Journal, EarlyView.
A Au(I) complex with a tethered coumarin fragment was synthesized and characterized by UV‐vis and emission spectroscopy. Its ability to facilitate photo‐driven cross‐coupling reactions through single‐electron and energy transfer events was evaluated. ABSTRACT Gold catalysis shows versatility in a wide range of challenging transformations, wherein light‐
Liliana Capulín Flores, Jacob J. van der Wal, Johannes E. M. N. Klein   +2 more
wiley   +1 more source

Nitrooxylation in Organic Synthesis: From Classical Nitrate Ester Formation to Modern Catalytic Strategies

Chemistry – A European Journal, EarlyView.
Nitrooxylation—the installation of nitrate esters (–ONO2) has evolved from classical mixed‐acid protocols to catalytic and mechano‐, flow‐, photo‐, and electrochemical strategies. This review delineates ionic and radical manifolds for C–ONO2 bond formation, emphasizing mechanistic control, selected substrate scope, and selectivity.
Jayanta Dey, Dmitry Katayev
wiley   +1 more source

New light on vitamin B12: The adenosylcobalamin-dependent photoreceptor protein CarH

South African Journal of Science, 2016
Adenosylcobalamin (AdoCbl), or coenzyme B12, is a cofactor for enzymes important in metabolism in humans (and other mammals) and bacteria. AdoCbl contains a Co-C bond and is extremely light sensitive, but, until recently, this light sensitivity appeared ...
Susan M. Chemaly
doaj   +1 more source

N─H or O─H Bond Activation With a Bicyclic Si4 Ring Compound

Chemistry – A European Journal, EarlyView.
The bicyclic Si4 ring compound with zwitterionic character reacts with NH3, H2O, and selected alcohols to give functionalized saturated silicon rings, siliconoid clusters with unsubstituted Si atoms, or simple 1,3‐addition products. The experimentally observed reactivity could be rationalized based on results from mechanistic calculations employing ...
Michael Quest, Florian Schreiner, Alexander Hepp, Constantin G. Daniliuc, Kasperi M. Salonen, Janne Körkkö, Heikki M. Tuononen, Felicitas Lips   +7 more
wiley   +1 more source

Mild C─F Activation of Azido(per)Fluoroalkanes

Chemistry – A European Journal, EarlyView.
Mild and selective activation of C(sp3)–F bonds in azido(per)fluoroalkanes using thiolates was developed, leading to novel functionalized azides. The reaction is initiated by nucleophilic attack of the sulfur atom to the terminal nitrogen of the azido group, followed by fluoride ion elimination.
Olena Shaitanova, María Martínez Mallo, Sergii Suikov, Blanka Klepetářová, Josef Filgas, Petr Slavíček, Lucie Bednárová, Petr Beier   +7 more
wiley   +1 more source