Unsymmetrical conjugated dendrons up to the third generation terminated with isophthalate ester were synthesized by the palladium-catalyzed Sonogashira coupling reaction, and the structures of the products were characterized by ¹H NMR, ¹³C NMR, mass spectra as well as elemental analysis. The dendritic skeleton was based on para- and meta-branched phenylacetylenes. A unique feature for these dendrons was that each electron-withdrawing group in them conjugated directly with an electron-donating alkoxy group. The preliminary investigation of their optical properties showed that UV/vis absorption edge and maximum wavelength of fluorescence emissions were red shifted with increasing generation.

Key words: conjugated dendron, ending group, isophthalate ester, Sonogashira coupling reaction