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New hyperbranched polyarylenes of high molecular weights are synthesized in high yields by copolycyclotrimerizations of diynes 1,4-diethynylbenzene, 4,4′-diethynylbiphenyl, 2,7-diethynylfluorene and 2,5-diethynylthiophene with monoynes 1-heptyne, 1-octyne and 1-dodecyne catalyzed by TaCl 5 –Ph 4 Sn in toluene. All the polymers show good solubility in common organic solvents, possess...
A germole-containing diacetylene, 1,1-diethynyl-2,3,4,5-tetraphenylgermole (2), was synthesized. Homopolymerization of 2 and its copolycyclotrimerization with 1-octyne were effected by TaCl5–Ph4Sn in toluene, producing completely soluble polymers (1) in moderate yields. The molecular structure of 1 was characterized by spectroscopic methods. The thermal stability of 1 was evaluated by thermogravimetric...
Alkyne polycyclotrimerizations are effected by tantalum- and cobalt-based catalysts, giving soluble hyperbranched polyarylenes (HPAs) with high molecular weights (M w up to ~2 x 10 5 ) in high yields (up to 99.9%). All the HPAs exhibit excellent thermal stability, losing little of their weights when heated to > 400 o C. The HPAs graphitize when pyrolyzed at 800 o ...
High molecular weight, hyperbranched polyarylenes were synthesized in high isolation yields by the copolycyclotrimerizations of 2,5-diethynylthiophene (1), 4,4 ' -biphenyldiyne (2), and 2,7-diethynylfluorenes (3) with 1-heptyne (4) and 1-dodecyne (5) using TaCl 5 -Ph 4 Sn as the catalyst in toluene. The structures of the polymers were characterized by IR, NMR, TGA, and UV analyses...
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