Synthesis and characterization of a novel carbazole cyclic oligomer and main-chain polymer

✍ Scribed by Yadong Zhang; Tatuso Wada; Hiroyuki Sasabe

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 167 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19970730)35:10<2041::aid-pola19>3.0.co;2-g

✦ Synopsis

The efficient synthesis of a novel cyclic carbazole tetramer and carbazole main-chain polymer via the Knoevenagel condensation has been developed. The carbazole cyclic tetramer could be obtained in a high yield by a one-stage Knoevenagel condensation of 3,6-diformyl-9-heptylcarbazole and 3,6-bis(cyanoacetoxymethyl)-9heptylcarbazole in tetrahydrofuran (THF) without the use of the high-dilution principle. The corresponding carbazole main-chain polymer could also be obtained as a main product by a two-stage Knoevenagel polycondensation. Detailed structural characterization of this novel oligomer by spectroscopy and elemental analysis confirmed the cyclic structure. The corresponding main-chain polymer with large molecular weight was found to be amorphous by differential scanning calorimetry. Studies on the nonlinear optical and photorefractive properties of these materials are in progress.