Geometric isomers of 9-picolylideneazafluorenes

By condensation of 1- and 4-azafluorenes with α(β,γ)-formylpyridines, we have synthesized 9-picolidene-1- and 4-azafluorenes, which we have isolated as pure Z and E isomers. Using PMR spectroscopy we have established their configuration. We discuss hypotheses concerning the dependence of the physical properties of the Z and E isomers of 9-picolylideneazafluorenes on their structure. © 1993 Plenum Publishing Corporation.