Sinha Vivek, Pribanic Bruno, de Bruin Bas, Trincado Monica, Grützmacher Hansjörg
Supramolecular and Homogeneous Catalysis Group, Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science park 904, 1098XH, Amsterdam, The Netherlands.
Department of Chemistry and Applied Biosciences ETH Zürich, Laboratory of Inorganic Chemistry, Vladimir-Prelog-Weg 1, Zürich, CH-8093, Switzerland.
Chemistry. 2018 Apr 11;24(21):5513-5521. doi: 10.1002/chem.201705957. Epub 2018 Feb 27.
Coordination of the diazadiene diolefin ligand (trop dad) to ruthenium leads to various complexes of composition [Ru(trop dad)(L)]. DFT studies indicate that the closed-shell singlet (CSS), open-shell singlet (OSS), and triplet electronic structures of this species are close in energy, with the OSS spin configuration being the lowest in energy for all tested functionals. Singlet-state CASSCF calculations revealed a significant multireference character for these complexes. The closed-shell singlet wavefunction dominates, but these complexes have a significant (≈8-16 %) open-shell singlet [d -Ru (L)(trop dad )] contribution mixed into the ground state. In agreement with their ambivalent electronic structure, these complexes reveal both metal- and ligand-centered reactivity. Most notable are the reactions with AdN , diazomethane, and a phosphaalkyne leading to scission of the C-C bond of the diazadiene (dad) moiety of the trop dad ligand, resulting in net (formal) nitrene, carbene, or P≡C insertion in the dad C-C bond, respectively. Supporting DFT studies revealed that several of the ligand-based reactions proceed via low-barrier radical-type pathways, involving the dad ligand radical character of the OSS or triplet species.
二氮二烯二烯烃配体（trop dad）与钌配位会生成各种组成的配合物[Ru(trop dad)(L)]。密度泛函理论（DFT）研究表明，该物种的闭壳单重态（CSS）、开壳单重态（OSS）和三重态电子结构能量相近，对于所有测试的泛函，OSS自旋构型能量最低。单重态的完全活性空间自洽场（CASSCF）计算表明这些配合物具有显著的多参考特征。闭壳单重态波函数占主导，但这些配合物有显著（约8 - 16%）的开壳单重态[d -Ru (L)(trop dad )]成分混入基态。与其矛盾的电子结构一致，这些配合物展现出以金属和配体为中心的反应性。最值得注意的是与叠氮、重氮甲烷和磷炔的反应，导致trop dad配体的二氮二烯（dad）部分的C - C键断裂，分别导致净（形式上的）氮烯、卡宾或P≡C插入到dad的C - C键中。支持性的DFT研究表明，一些基于配体的反应通过低势垒自由基型途径进行，涉及OSS或三重态物种的dad配体自由基特征。
