Ring-Opening Copolymerization Using Simple Fe(III) Complexes and Metal- and Halide-Free Organic Catalysts
Ring-Opening Copolymerization Using Simple Fe(III) Complexes and Metal- and Halide-Free Organic Catalysts
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DOI：
10.1021/acs.macromol.1c01211
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发表时间：
2021-09-13
期刊：
影响因子：
5.5
通讯作者：
Jones, Matthew D.
中科院分区：
文献类型：
--
作者：
Driscoll, Oliver J.;Stewart, Jack A.;Jones, Matthew D.
作为新发现的一元体系的一部分，14种合成简单、空气稳定、结构多样的Fe（III）配合物，包括salalen、salen、salan和thiolen框架，被用作苯酐（PA）和环氧环己烯（CHO）开环共聚（ROCOP）的催化剂，而不需要额外的添加剂，如辅助催化剂。得到了分子量合理、分散性窄、酯链百分比高的交联聚（1,2-环己烯-1,2-邻苯二甲酸酯）{聚（CHO-co-PA）}。对构效关系进行了研究和讨论。最有趣的发现是，在进行“配体控制”ROCOP实验时（强调了这种检查在催化中的重要性），所有这些有机催化剂的性能都优于它们的刘易斯酸性Fe（III）类似物；这些结果具有重要意义，因为开发了一种简单、不含金属和卤化物的有机催化单组分ROCOP方法。文献中很少有有机催化剂的例子，倾向于依赖于具有更苛刻，空气敏感的化学物质的双组分系统，这些结果提供了希望，更多的反应性，有效的系统可能在一个非常处于起步阶段的领域，但毫无疑问会出现，并可能证明对未来可持续聚合研究至关重要。通过差示扫描量热法分析获得了热性能，对于非晶共聚物，T-g值范围为35℃，从100℃到可观的135℃。
A comprehensive range of 14 synthetically simple, air-stable, and structurally diverse Fe(III) complexes, comprising salalen, salen, salan, and thiolen frameworks, were applied as catalysts to the ring-opening copolymerization (ROCOP) of phthalic anhydride (PA) and cyclohexene oxide (CHO) without the need for extra additives, such as co-catalysts, as part of a newly discovered unary system. Alternating poly(1,2-cyclohexylene-1,2-phthalate) {poly(CHO-co-PA)} was obtained with reasonable molecular weight, narrow dispersity, and high % ester linkage. Structure-activity relationships have been investigated and discussed. The most interesting discovery was that while performing "ligand control" ROCOP experiments (highlighting the importance of such checks in catalysis), all these organocatalysts outperformed their Lewis acidic Fe(III) analogues; these results are significant as a simplistic, metal- and halide-free, organocatalytic single-component approach to ROCOP was developed. There are few examples of organocatalysts in the literature, tending to rely on two component systems with harsher, air-sensitive chemicals, and these results provide hope that more reactive, effective systems are possible in an area very much in its infancy but will no doubt emerge and potentially prove vital to future sustainable polymerization research. Thermal properties were accessed via differential scanning calorimetry analysis, and for the amorphous copolymers, the T-g values ranged by 35 degrees C from 100 degrees C to a respectable 135 degrees C.