能够从同一单体受控合成线性和支链聚合物的方法学将是聚合物合成和加工的新途径。在这里,我们首先描述对咔唑基的C(3)-C(3')和C(6)-C(6')偶联反应中的一个或两个的控制。在第二种方法中,使用化学和电化学氧化剂聚合包含两个咔唑的相同单体,从而导致线性聚合物在弱氧化剂中的拓扑可控生长或在强氧化剂中交联的聚合物链的拓扑可控生长,以及逐步增长聚合的满意长链增长(M n = 6.0×10 4 g mol -1,M w / M n= 2.3)。这种使用廉价试剂和少量废物的非常简单的聚合反应为聚合物的合成和加工提供了一条灵活的途径。
based on which memory device fabrication and electrically bistable behavior evaluation are technically infeasible. Whereas PDI-6Cz readily self-assembles into highly uniform nano-films with a considerably smooth surface, in which the X-ray diffraction study indicates strong π–π stacking between the aromatic skeletons. Further characterization indicates that sandwich memory devices using a PDI-6Cz nano-film
Carbazole-containing gelators derived from L-isoleucine have been developed. They form elongated self-assembled fibers in common organic solvents and in liquid crystals, leading to the efficient gelation of these solvents. Spectroscopic studies indicate that the carbazolyl moieties are one-dimensionally stacked in the fibers. The stacking of the carbazolyl moieties is reversible by the association and dissociation of the hydrogen bonding. Moreover, anisotropically aligned fibers have been obtained in a homogeneously oriented smectic state of liquid crystals. This template behavior would serve as a versatile approach to the functionalization of self-assembled fibers. (c) 2007 Elsevier Ltd. All rights reserved.