Photochemistry cyclooctatetraene

The cyclooctatetraenyl dianion 19 (COT-2) is an aromatic 10a electron system and hence can be readily prepared from cyclooctatetraene by reduction (alkali metals or electrochemically). An early report [36] of the photochemistry of COT-2 in the presence of weak acids such as amines and terminal alkynes showed that it is protonated in the excited state (to give the monoanion) COT-2 is more basic in the excited state than in the ground state. However, in the absence of such weak acids, photolysis of COT-2 results in electron photoejection [37-39]. The electron photoejection process and subsequent chemistry has been studied in... 

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