摘要:
Poly(aminophthalimide) (PAP) dimers and trimers have been synthesized by palladium-catalyzed cross-coupling reactions of 3-aminophthalimides with 3-chloro- and 3,6-dichlorophthalimide, respectively. When Pd(OAc)(2), XPhos (2-dicyclohexylphosphino-2',4',6'- triisopropylbiphenyl), and K3PO4 are used, the C-N bond-forming reactions proceed quantitatively. The structures of those oligomers are examined by experimental and theoretical techniques including NMR, IR, single-crystal X-ray diffraction, and DFT calculations. The strong preference for cisoid structure of the diphthalimidylamine unit bearing a bifurcate hydrogen bonding is disclosed. Therefore, the aminophthalimide backbone is a highly promising candidate for the construction of a dynamically ordered helical structure. (C) 2007 Elsevier Ltd. All rights reserved.