Synthesis and evaluation of fluorescent materials for colour control of peroxyoxalate chemiluminescence. I. The phenylethynylation of anthraquinone

Abstract

The synthesis of 9,lO-bis(phenylethyny1)anthracene has been examined in detail prior to the synthesis of a series of phenylethynyl substituted aromatic compounds which are of interest as fluorescent materials for peroxyoxalate chemiluminescence. Reductions of the 9,lO-bis(phenylethyny1)-9,lOdihydroanthracene-9,lO-diol precursor by stannous chloride and by sodium hypophosphite-potassium iodide both gave a series of byproducts, in addition to 9,lO-bis(phenylethyny1)anthracene. The formation of these compounds is interpreted in terms of a free-radical process. The interaction of 10-hydroxy-10-(phenylethyny1)anthrone with both the reducing systems has been rationalized and the reaction with concentrated sulfuric acid reinterpreted. Scheme 1Rauhut, M. M.,

Reductive Aromatization/Dearomatization and Elimination Reactions to Access Conjugated Polycyclic Hydrocarbons, Heteroacenes, and Cumulenes

“…Several studies suggest that acid is critical to the mechanism, while there are also numerous examples of the reaction proceeding without the addition of a Brønsted acid. Still other studies, notably by Dahl and Mills, Wu and co‐workers, and Hanhela and Paul implicate radical species in the mechanism. These discrepancies indicate that further investigations are definitely necessary to verify the mechanism.…”

“…Since hydriodic acid (HI) is both an acid and a source of iodide, it can be employed to carry out reductive aromatization reactions of diols. Rio and co‐workers first demonstrated this method in 1948 with the reduction of an 9,10‐anthracene diol to the desired substituted 9,10‐bis(phenylethynyl)anthracene in nearly quantitative yield (see Scheme c) . In 2009, Kakiuchi and co‐workers were able to reduce anthraquinone 94 to tetraarylanthracene 95 by stirring the dione in aqueous acetic acid with HI for four days at 140 °C (Scheme ) …”

“…There are relatively few reports of this reduction method, probably due to moderate yields and by‐product formation found in most of the reported examples . For instance, depending on the substitution pattern of the precursor, the use of KI can lead to 1,4‐shift products such as 9‐anthrones (Scheme ) .…”

Chemiluminescent Properties of Novel Biphenyl Analogue Blue Fluorophores

“…A variety of uses has been developed in recent years: emergency lights during power failures; small portable lights for camping, backpacking, and jogging; marking lights for life jacket; lures for commercial fishing; and a wide spectrum of novel uses. 2 Several different chemiluminescent fluorophores were employed to produce different colors [2][3][4][5][6][7] : N,N'-bis(2,6-diisopropylphenyl)-1,6,7,12-tetrakis(p-tert-butylphenoxy)-3,4,9,10-perylenetetracarboxydiimide (red), rubrene (red), 2-chloro-9,10-bis(p-methoxyphenyl)anthracene (blue), 9,10-bis(phenylethynyl)anthracene (green) and 1-chloro-9,10-bis(phenylethynyl)-2-chloroanthracene (yellow) are among them.…”

A General Synthesis of Disubstituted Rubicenes

“…(3a) gives a diol 4a, which can be reduced with sodium hypophosphite/potassium iodide [9] to the anthracene 5a Rubicene (1a) is an interesting heptacyclic arene which and cyclized (KOH, quinoline) to afford rubicene (1a) in has been known for over 100 years. [2] Rubicene has been good yield.…”