Abstract Chemical phenomena dictating the spontaneous-ignition of coal remain highly speculative with some of the most intriguing questions appearing unaddressed. In this communication, we deploy a synergistic experimental-theoretical approach to elucidate the definite role of singlet-biradical PAHs in driving the low-temperature oxidation of coal. We establish that, five linearly-fused benzene rings (i.e., pentacene, as a model compound for the PAH content in coal, and an example of short-chain graphene nanoribbons) ignites 200 °C lower than the corresponding temperature for naphthalene.

中文翻译：

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大型多环芳烃中的单线态双自由基特征触发煤的自燃

摘要 决定煤自燃的化学现象仍然具有高度推测性，一些最有趣的问题似乎没有得到解决。在这次交流中，我们采用了一种协同的实验理论方法来阐明单线态双基多环芳烃在推动煤的低温氧化中的明确作用。我们确定，五个线性稠合的苯环（即并五苯，作为煤中 PAH 含量的模型化合物，以及短链石墨烯纳米带的一个例子）比萘的相应温度低 200 °C。