Vivek Sinha, Bruno Pribanic, Bas de Bruin, Monica Trincado, Hansjörg Grützmacher
Chemistry (Weinheim an der Bergstrasse, Germany) 2018 Apr 11Coordination 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. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
Vivek Sinha, Bruno Pribanic, Bas de Bruin, Monica Trincado, Hansjörg Grützmacher. Ligand- and Metal-Based Reactivity of a Neutral Ruthenium Diolefin Diazadiene Complex: The Innocent, the Guilty and the Suspicious. Chemistry (Weinheim an der Bergstrasse, Germany). 2018 Apr 11;24(21):5513-5521
PMID: 29341297
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