Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States.
J Am Chem Soc. 2011 Aug 31;133(34):13421-9. doi: 10.1021/ja2024355. Epub 2011 Aug 9.
Cyclic dendronized polymers represent a new class of polymers which exhibit a donut-like "toroidal" shape. Two previous unreported methods for preparing this architecture, the divergent "graft-from" and the convergent click "graft-to" approaches, are explored and the resulting products fully characterized. This route is particularly attractive because it enables production of exact linear and cyclic dendronized analogues, enabling direct comparison of their physical properties. In this preliminary work, the divergent "graft from" approach appears to lead to materials with broad PDI at high DP, whereas the "graft to" approach yields more well-defined dendronized cyclic polymers at larger DP. On the basis of reports to date, a combination of click cyclization followed by click "grafting to" provides the most versatile route for the synthesis of cyclic dendronized polymers.
环状树枝状聚合物代表了一类新型聚合物，它们呈现出类似甜甜圈的“轮状”形状。本文探索了两种以前未报道的制备这种结构的方法，即发散的“从支化”和收敛的点击“接枝到”方法，并对得到的产物进行了充分的表征。该方法特别有吸引力，因为它能够制备精确的线性和环状树枝状类似物，从而可以直接比较它们的物理性质。在这项初步工作中，发散的“从支化”方法似乎导致在高 DP 时具有较宽 PDI 的材料，而“接枝到”方法在较大 DP 时产生更明确的树枝状环状聚合物。根据迄今为止的报道，点击环化后再进行点击“接枝到”的组合为环状树枝状聚合物的合成提供了最通用的方法。
