Teo Yew Chin, Lai Holden W H, Xia Yan
Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.
Chemistry. 2017 Oct 12;23(57):14101-14112. doi: 10.1002/chem.201702219. Epub 2017 Sep 14.
Ladder polymers are unique in that their backbones consist of fused rings with adjacent rings having two or more atoms in common. The restriction of bond rotations in rigid ladder polymers greatly limits their conformational freedom, leading to many intriguing and unique properties. As a non-traditional type of polymers, rigid ladder polymers are of great fundamental interest and technical importance as advanced materials for applications such as membrane gas separation and organic electronics. Ladder polymers can be divided into non-conjugated (with kinked conformations) and conjugated (with planar conformations) structures. Their synthesis can be broadly classified into two general strategies: direct ladder polymerization, and zipping of a linear precursor polymer. This Concept article outlines the historical development of ladder polymers and the chemical strategies used for their synthesis; highlights the challenges associated with their synthesis and characterization, and presents opportunities and outlooks for this unique and intriguing type of polymers.
梯形聚合物的独特之处在于其主链由稠环组成，相邻的环有两个或更多的共同原子。刚性梯形聚合物中键旋转的限制极大地限制了它们的构象自由度，从而导致许多有趣和独特的性质。作为一种非传统类型的聚合物，刚性梯形聚合物作为膜气体分离和有机电子等应用的先进材料，具有极大的基础研究价值和技术重要性。梯形聚合物可分为非共轭（具有扭结构象）和共轭（具有平面构象）结构。它们的合成大致可分为两种一般策略：直接梯形聚合和线性前体聚合物的拉链反应。这篇概念文章概述了梯形聚合物的历史发展以及用于其合成的化学策略；强调了与其合成和表征相关的挑战，并展示了这种独特而有趣的聚合物类型的机遇和前景。
