The photochemical approach to the functionalization of open-chain and cyclic alkanes: 1. Single electron transfer oxidation

Irradn. of 1,2,4,5-benzenetetracarbonitrile (TCB) in the presence of various open-chain, cyclic and polycyclic alkanes leads to single electron transfer (SET),as demonstrated by the detection of the TCB radical anion, TCB•-. This affords a way to evaluate the oxidn. potential of such substrates, which are difficult to measure voltammetrically. The thus formed alkane radical cations undergo deprotonation, in accordance with thermochem. predictions showing that these species are strong acids (pKa < -13).