Nine mostly novel aromatic Schiff bases containing from two-to-four terminal ethynyl groups and one or two methanimine groups per one molecule are reported. The spectral and density functional theory characteristics and the extent of conjugation are discussed in connection with the structure and architecture of the prepared compounds.
The applicability of compounds as building blocks for conjugated polymers is shown in TaCl5-catalyzed polycyclotrimerization (proceeding in ethynyl groups) yielding either soluble luminescent or insoluble microporous polymers.