Six-membered-ring photocyclization in phenyl-substituted p-phenylenevinylene derivatives: a potential factor of instability in conjugated polymers†
Abstract
A synergistic effect of cis/trans-isomerization and photocyclization results in a very efficient photocyclization of 2-vinylbiphenyl to 9,10-dihydrophenanthrene (∼100%) in the presence of a cyano-substituent, which is the first observation of six membered ring photocyclization in phenyl-substituted p-phenylenevinylene derivatives.