Hyperbranched Poly aroylarylene s

It is known that an aroylacetylene undergoes cyclotrimerization in the presence of diethylamine or when refluxed in DMF [101-103]. Supposedly, a small amount of DMF solvent has decomposed at the high temperature (i.e., the boiling point of DMF) to release dimethylamine, which served as the catalytic species [103]. Our attempted polymerization carried out in the presence of diethylamine, however, produced polymers in very low yields (7-21%) [105]. Good to excellent polymer yields were achieved when the bis(aroylacetylene)s were refluxed in DMF/tetralin mixtures for 72 h. Our attempts to shorten the reaction time and to increase the polymer yield by using diphenylamine as the catalyst failed. Use of piperidine as the cata- 

with the help of spectral analyses, the hyperbranched structures of the poly(aroylarylene)s were confirmed. Thanks to the 1,3,5-regioselectivity of the cyclotrimerization reaction, the NMR spectra of the hb-PAAs were 

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