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 °C from 100 °C to a respectable 135 °C.

中文翻译：

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使用简单的 Fe(III) 配合物和无金属和无卤化物的有机催化剂进行开环共聚

将 14 种合成简单、空气稳定且结构多样的 Fe(III) 配合物作为催化剂应用于邻苯二甲酸酐 (PA) 的开环共聚 (ROCOP) ) 和氧化环己烯 (CHO) 作为新发现的一元系统的一部分，无需额外的添加剂，例如助催化剂。交替聚（1,2-亚环己基-1,2-邻苯二甲酸酯）{poly(CHO- co-PA)} 具有合理的分子量、窄的分散性和高％的酯键。已经研究和讨论了构效关系。最有趣的发现是，在进行“配体控制”ROCOP 实验（强调此类检查在催化中的重要性）时，所有这些有机催化剂的性能都优于它们的路易斯酸性 Fe(III) 类似物；这些结果非常重要，因为开发了一种简单的、不含金属和卤化物的有机催化单组分 ROCOP 方法。文献中有机催化剂的例子很少，往往依赖于具有更苛刻、对空气敏感的化学物质的两个组分系统，这些结果为更具反应性、在一个处于起步阶段的领域，有效的系统是可能的，但毫无疑问会出现，并可能证明对未来的可持续聚合研究至关重要。已访问热属性通过差示扫描量热分析，对于无定形共聚物，T _g值范围为 35 °C，从 100 °C 到可观的 135 °C。