Coronene chemistry

The synthetically most valuable intermediate in heterofullerene chemistry so far has been the aza[60]fulleronium ion C59N (28). It can be generated in situ by the thermally induced homolytic cleavage of 2 and subsequent oxidation, for example, with O2 or chloranil [20-24]. The reaction intermediate 28 can subsequently be trapped with various nucleophiles such as electron-rich aromatics, enolizable carbonyl compounds, alkenes and alcohols to form functionalized heterofullerenes 29 (Scheme 12.8). Treatment of 2 with electron-rich aromatics as nucleophilic reagent NuH in the presence of air and excess of p-TsOH leads to arylated aza[60]fullerene derivatives 30 in yields up to 90% (Scheme 12.9). A large variety of arylated derivatives 30 have been synthesized, including those containing cor-annulene, coronene and pyrene addends [20, 22-25]. 

The HPLC methods cannot be used to routinely monitor the other PAHs because the instrumentation is rather sophisticated and data interpretation and analysis requires a high level of expertise. Instead simple UV absorbance methods are used to measure the absorbance at wavelengths characteristic of certain key PAHs. These include 305 nm for coronene, 335 nm for pyrene, 345 nm for dibenzo[cdJm]perylene, and 495 nm for dinaphtho[2,l,8,7-defg 2, r8, 7 -opqr]pentacene. Tracking of each of these absorbances from process startup allows process engineers to follow the buildup of the PAHs and gain an idea of the chemistry going on within the process. 

As in the case of pyrones, the contribution to carbon basicity of n-cation interactions in model aromatic systems was investigated by carrying out ab initio calculations [64], The energies for benzene-HjO pyrene-benzene-HjO", and coronene-H30+ interactions were considered in an attempt to understand the basicity contributions of the basal plane. These theoretical results did support the experimental data concerning the ability of basal planes to contribute to carbon basicity and suggested that n-cation interactions may play an important role in the surface chemistry of carbon materials. 

Jenness, G. R., Jordan, K. D. (2009). Df-dft-sapt investigation of the interaction of a water molecule to coronene and dodecabenzo-coronene Implications for the water-graphite interaction. Journal of Physical Chemistry C, 113, 10242-10248. 

Shen, H.-Ch., Tang, J.-M., Chang, H.-K., Yang, C.W. and Liu, R.S. (2005) Short and efficient synthesis of coronene derivatives via ruthenium-catalyzed benzannulation protocol. Journal of Organic Chemistry, 70(24), 10113-10116. 

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