Homogenous Synthesis of Monodisperse High Oligomers of 3-Hexylthiophene by Temperature Cycling.
Homogenous Synthesis of Monodisperse High Oligomers of 3-Hexylthiophene by Temperature Cycling.
复制标题
通过温度循环均相合成 3-己基噻吩单分散高低聚物。
DOI：
10.1021/jacs.9b08240
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发表时间：
2019
影响因子：
15
通讯作者：
D. Seferos
中科院分区：
文献类型：
--
作者：
George R Mckeown;Shuyang Ye;Susan Cheng;D. Seferos
虽然单分散聚合物在自然界中无处不在，但它们仍然难以合成化学家。对聚合物长度和结构的绝对控制对于赋予化学功能性、可再现性能和特定固态行为至关重要。精确的聚合物长度已被证明是非常难以控制的。最成功的实例通常类似于固相寡核苷酸或肽合成，其中聚合物一次一个单元地构建，每个顺序的单体添加需要纯化和脱保护（或其他官能团活化）步骤。我们已经发现了一个逐步均相催化剂转移聚合制备单分散低聚（3-己基噻吩），使用温度限制添加到一个单元每个链每个循环。这是第一个报道的单分散低聚物的一锅合成的例子，不需要额外的纯化或中间步骤。我们希望温度循环“冻结”中间体的策略可推广到其他活性聚合技术，例如其他催化剂转移聚合系统，以及其中静止状态涉及催化剂和生长链之间的关联的那些。
Whereas monodisperse polymers are ubiquitous in Nature, they remain elusive to synthetic chemists. Absolute control over polymer length and structure is essential to imparting chemical functionality, reproducible properties, and specific solid-state behavior. Precise polymer length has proven to be extremely difficult to control. The most successful examples are generally similar to solid-phase oligo nucleotide or peptide synthesis, wherein the polymer is built up one unit at a time with each sequential monomer addition requiring purification and deprotection (or other functional group activation) step. We have discovered a stepwise homogeneous catalyst-transfer polymerization to prepare monodisperse oligo(3-hexylthiophene) using temperature to limit additions to one unit per chain per cycle. This is the first reported example of a one-pot synthesis of monodisperse oligomers that requires no additional purification or intermediate steps. It is our hope that the strategy of temperature cycling to "freeze" intermediates will be generalizable to other living polymerization techniques, such as other catalyst-transfer polymerization systems, and those where a resting state involves an association between the catalyst and growing chain.