Solvent-Dependent Behavior of Phenanthrene-Amine Intramolecular Exciplexes
摘要:
The solvent dependence of the photophysical and photochemical behavior of several ((N,N-dimethylamino)alkyl)phenanthrenes in which the amino group is attached to the phenanthrene at C-9 or C-1 via a short polymethylene chain has been investigated. Intramolecular exciplex fluorescence is observed in moderately polar solvents but not in nonpolar solvents. The solvent dependence of exciplex fluorescence is attributed to exergonic formation of solvated exciplexes with loose geometries in polar solvents and endergonic exciplex formation in nonpolar solvents. in the case of the (aminoethyl)phenanthrene exciplex fluorescence is observed in highly polar solvents, including dimethylformamide, dimethyl sulfoxide, and acetonitrile-water binary mixtures and in frozen polar glasses. In the case of the (aminomethyl)phenanthrene moderately efficient photodeamination to yield 9-methylphenanthrene and 1,2-di-9-phenanthrylethane is observed. The solvent and temperature dependence of the kinetics of exciplex formation and decay are discussed and compared to results for other intramolecular arene-amine exciplexes.
A strategy for generating aryl radicals from arylborates through organic photoredox catalysis: photo-Meerwein type arylation of electron-deficient alkenes
Photoinduced reactions of arylboronic acids with electron deficient alkenes under mild organic photoredox catalysis conditions lead to the formation of Meerwein arylation type adducts via the generation of aryl radicals.
deboronative reactions using two-molecule organic photoredox catalysts, namely, phenanthrene (Phen) and biphenyl (BP), as electrondonors and 9-cyano-10-methoxycarbonylanthracene 1a as an electronacceptor were achieved. The high solubility of 1a significantly improved the reaction efficiency and product yield. In addition, the facile tuning of the oxidation potential of the electron-donor moleculevia the
Visible‐Light‐Induced Decarboxylative and Deboronative Radical Addition to Alkenes in Two‐Molecule Photoredox System Using Dibenzo[
<i>g,p</i>
]chrysene
Visible-light-induced decarboxylative and deboronative radicaladdition of aliphatic carboxylic acids and arylboronic acid pinacol esters to electron-deficientalkenes using two-molecule organic photoredox catalysts, such as dibenzo[g,p]chrysene and 1,4-dicyanobenzene, proceeded efficiently to furnish radical adducts via the generation of alkyl and aryl radicals.
使用双分子有机光氧化还原催化剂,如二苯并[ g, p ] chrysene和1,4-二氰基苯,可见光诱导的脂肪族羧酸和芳基硼酸频哪醇酯对缺电子烯烃的脱羧和脱硼自由基加成反应有效进行通过产生烷基和芳基自由基来提供自由基加合物。
RHODES, R. ALLEN;BOYKIN, DAVID W., SYNTH. COMMUN., 18,(1988) N 7, 681-687