Carbene formation from excited C6-C10 cycloalkane molecules

During radiolysis and vacuum-ultraviolet photolysis of liquid n-alkanes and larger cycloalkanes, part of the main product, hydrogen is formed by unimolecular elimination. Unimolecular H2 elimination from a single carbon atom is demonstrated to be the basic decomposition process occurring from the low energy excited states of C6-C10 cycloalkanes. The carbene produced in this reaction is unimolecularly stabilized by transannular insertion or hydrogen atom migration. The carbene lifetime is probably longer than 10-100 ps. (author)