The palladium-catalyzed cross-coupling reaction of 2,3,6,7-tetrabromonaphthalene
diimide with various aryl- and alkynylstannanes afforded a series
of hitherto unknown tetraaryl- and tetraethynyl-substituted naphthalene
diimides (NDIs). UV/Vis spectroscopic studies revealed
that the absorption maxima of ethynyl-substituted NDIs are significantly
bathochromically shifted compared to those of unsubstituted and
tetraaryl-substituted NDIs. Cyclic voltammetry investigations showed
that ethynyl substituents shift the reduction potentials of NDIs
anodically, thus these NDI derivatives are interesting candidates
for air-stable n-channel organic field-effect transistors.
chromophores - arylenes - cross-coupling - Stille reaction - catalysis