德国哥廷根大学的Sven Schneider研究小组近日取得一项新成果。经过不懈努力，他们开发出具有过渡金属取代基的三线态卡宾。2024年8月5日出版的《自然-化学》发表了这项成果。

团队报道了三线态金属卡宾(M–C–SiMe₃, M=Pd^II, Pt^II)的合成和表征，这些三线态卡宾在非低温条件下持续存在，团队还描述了它们对卡宾碳氢插入和羰基化的选择性反应性。化学键分析表明，沿两个π键平面的自旋极化的拉扯相互作用具有显著的稳定性，这与拉扯单线态卡宾的成键有着根本的区别。他们认为，这种键合模型扩展了稳定开壳卡宾电聚体的关键策略，并缩小了与碳炔配合物的概念差距。

据悉，通过π相互作用稳定电子单重态的策略推动了卡宾(R¹-C-R²)化学的非凡进展。相比之下，缺乏类似的有效方法来获得真正的在，非低温条件下具有可观寿命的三重态的卡宾，这阻碍了它们在合成和催化中的利用。过渡金属取代代表了一种潜在的策略，但金属卡宾(M-C-R)通常代表了已建立的碳炔配合物(M≡C-R)的高激发电子构型。

附：英文原文

Title: Triplet carbenes with transition-metal substituents

Author: Lv, Ze-Jie, Eisenlohr, Kim A., Naumann, Robert, Reuter, Thomas, Verplancke, Hendrik, Demeshko, Serhiy, Herbst-Irmer, Regine, Heinze, Katja, Holthausen, Max C., Schneider, Sven

Issue&Volume: 2024-08-05

Abstract: The extraordinary advances in carbene (R1–C–R2) chemistry have been fuelled by strategies to stabilize the electronic singlet state via π interactions. In contrast, the lack of similarly efficient approaches to obtain authentic triplet carbenes with appreciable lifetimes beyond cryogenic temperatures hampers their exploitation in synthesis and catalysis. Transition-metal substitution represents a potential strategy, but metallocarbenes (M–C–R) usually represent high-lying excited electronic configurations of the well-established carbyne complexes (M≡C–R). Here we report the synthesis and characterization of triplet metallocarbenes (M–C–SiMe3, M=PdII, PtII) that are persistent beyond cryogenic conditions, and their selective reactivity towards carbene C–H insertion and carbonylation. Bond analysis reveals significant stabilization by spin-polarized push–pull interactions along both π-bonding planes, which fundamentally differs from bonding in push–pull singlet carbenes. This bonding model, thus, expands key strategies for stabilizing the open-shell carbene electromers and closes a conceptual gap towards carbyne complexes.

DOI: 10.1038/s41557-024-01597-8

Source: https://www.nature.com/articles/s41557-024-01597-8