Strategies toward Controlling the Topology of Nonlinear Poly(thiophenes)

Junction-Controlled Topological Polymerization

Methodology that enables the controlled synthesis of linear and branched polymers from an identical monomer will be a novel pathway for polymer synthesis and processing. Herein we first describe the control of one or both of the C(3)-C(3') and C(6)-C(6') coupling reactions of carbazolyl. In a second approach, an identical monomer containing two carbazolyls is polymerized using chemical and electrochemical oxidizers, leading to topologically controllable growth of linear polymers in weak oxidizer or of cross-linked polymer chains in strong oxidizer, with satisfactory long chain propagation of step growth polymerization (M_n =6.0×10⁴  g mol^-1 , M_w /M_n =2.3). This very simple polymerization with cheap reagents and low levels of waste has provided a flexible pathway for synthesis and processing of polymers.