136809-42-2

Upstream product

• 523-27-3 9,10-Dibromoanthracene 
• 623-00-7 4-bromobenzenecarbonitrile 
• 18750-95-3 9,10-bis(trimethylsilyl)ethynylanthracene 
• 136384-82-2 4,4'-(1E,1'E)-2,2'-(anthracene-9,10-diyl)bis(ethene-2,1-diyl)dibenzonitrile 

Relevant academic research and scientific papers

Why triple bonds protect acenes from oxidation and decomposition

An experimental and computational study on the impact of functional groups on the oxidation stability of higher acenes is presented. We synthesized anthracenes, tetracenes, and pentacenes with various substituents at the periphery, identified their photooxygenation products, and measured the kinetics. Furthermore, the products obtained from thermolysis and the kinetics of the thermolysis are investigated. Density functional theory is applied in order to predict reaction energies, frontier molecular orbital interactions, and radical stabilization energies. The combined results allow us to describe the mechanisms of the oxidations and the subsequent thermolysis. We found that the alkynyl group not only enhances the oxidation stability of acenes but also protects the resulting endoperoxides from thermal decomposition. Additionally, such substituents increase the regioselectivity of the photooxygenation of tetracenes and pentacenes. For the first time, we oxidized alkynylpentacenes by using chemically generated singlet oxygen (1O2) without irradiation and identified a 6,13-endoperoxide as the sole regioisomer. The bimolecular rate constant of this oxidation amounts to only 1 × 10 5 s-1 M-1. This unexpectedly slow reaction is a result of a physical deactivation of 1O2. In contrast to unsubstituted or aryl-substituted acenes, photooxygenation of alkynyl-substituted acenes proceeds most likely by a concerted mechanism, while the thermolysis is well explained by the formation of radical intermediates. Our results should be important for the future design of oxidation stable acene-based semiconductors.

Reversible photooxygenation of alkynylanthracenes: Chemical generation of singlet oxygen under very mild conditions

In the dark and very fast: The generation of singlet oxygen ( 1O2) from endoperoxides, which are readily available by photooxygenation of the corresponding anthracenes, proceeds within minutes in the dark (see scheme), a rate hitherto unknown for other anthracenes or naphthalenes. This provides an efficient chemical source of singlet oxygen under very mild conditions.

Synthesis and Absorption/Emission Spectroscopic Properties of Bis(phenylethynyl)benzenes and 9,10-Bis(phenylethynyl)anthracenes

A series of bis(phenylethynyl)benzenes 3 and 9,10-bis(phenylethynyl)anthracenes 4 was synthesized by bromination-dehydrobromination reaction or newly developed direct triple bond formation reaction from styrylstilbenes 1 or distyrylanthracenes 2.Subsequently systematic investigations were carried out on their absorption and fluorescence spectra, and their chemiluminescence properties.The following points are apparent; (a) a linear relationship between and Hammett's ?P of compounds 3 and 4 was observed, (b) a significant relationship between Stokes' shift of 4 and ?P was observed and (c) in the series of compounds 4 the electron-donating ability of the substituents has a pronounced effect on the chemiluminescence properties.

Direct CC Triple Bond Formation from the C=C Double Bond with Potassium tert-Butoxide in Dimethylformamide containing Trace Amounts of Oxygen

A novel and facile method for direct acetylenic bond formation from the C=C double bond by treatment with KOBut in dimethylformamide has been found both in a 9,10-bis(4'-substituted styryl)anthracene series and in a 4-substituted 4'-nitro-stilb