Nickel-catalyzed catalyst transfer polycondensation (CTP) of thiophenes is an efficient strategy for the controlled synthesis of polythiophenes. However, a detailed view of its reaction mechanism has remained elusive with unresolved questions regarding the geometry and bonding of critical Ni(0) thiophene intermediates. Herein, we provide experimental and computational evidence of structurally characterized square planar η²-Ni(0)-thiophene species and their relevance to the mechanism of CTP. These results confirm the viability of C,C-η² bound intermediates in CTP of thiophenes, providing an electronic rationale for the stability of such species, and thus that such processes can proceed as living polymerizations. We further show that C,S-κ² species may also be relevant in nickel-catalyzed CTP of thiophenes, providing new avenues for exploitation and optimization.

中文翻译：

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识别催化剂转移聚合中缺失的环节。

镍催化的噻吩催化剂转移缩聚（CTP）是聚噻吩可控合成的有效策略。然而，由于关键 Ni(0) 噻吩中间体的几何形状和键合问题尚未解决，因此对其反应机制的详细了解仍然难以捉摸。在此，我们提供了结构特征方形平面 η ² -Ni(0)-噻吩物种及其与 CTP 机制的相关性的实验和计算证据。这些结果证实了噻吩CTP中C,C-η ²结合中间体的可行性，为此类物质的稳定性提供了电子原理，因此此类过程可以作为活性聚合进行。我们进一步表明，C,S-κ ²物种也可能与镍催化噻吩的 CTP 相关，为开发和优化提供了新的途径。