Coordination of the diazadiene diolefin ligand (trop2 dad) to ruthenium leads to various complexes of composition [Ru(trop2 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 [d7 -RuI (L)(trop2 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 AdN3 , diazomethane, and a phosphaalkyne leading to scission of the C-C bond of the diazadiene (dad) moiety of the trop2 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.

中文翻译：

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中性钌二烯烃二氮杂二烯配合物的配体和金属反应性：无辜者、有罪者和可疑者。

二氮杂二烯二烯配体 (trop2 bad) 与钌的配位产生了各种成分 [Ru(trop2 bad)(L)] 的配合物。DFT 研究表明，该物种的闭壳层单线态 (CSS)、开壳层单线态 (OSS) 和三线态电子结构的能量接近，其中 OSS 自旋构型是所有测试泛函中能量最低的。单重态 CASSCF 计算揭示了这些配合物的显着多参考特征。闭壳层单线态波函数占主导地位，但这些配合物具有显着的（约 8-16 %）开壳层单线态 [d7 -RuI (L)(trop2 bad.- )] 贡献，混合到基态中。与它们的矛盾电子结构一致，这些配合物揭示了以金属和配体为中心的反应性。最值得注意的是与 AdN3、重氮甲烷和磷炔的反应，导致 trop2 bad 配体的二氮杂二烯 (dad) 部分的 CC 键断裂，从而在爸爸CC债券，分别。支持DFT的研究表明，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或三联体物种的爸爸配体自由基特征。