Synthesis, Characterization, and Catalytic Reactivity of {CoNO} 8 PCP Pincer Complexes.

Autor: Pecak J; Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria., Eder W; Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria., Stöger B; X-Ray Center, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria., Realista S; Instituto de Tecnologia Química e Biológica António Xavier, ITQB NOVA, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal., Martinho PN; BioISI - Biosystems and Integrative Sciences Institute, DQB, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal., Calhorda MJ; BioISI - Biosystems and Integrative Sciences Institute, DQB, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal., Linert W; Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria., Kirchner K; Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
Jazyk: angličtina
Zdroj: Organometallics [Organometallics] 2020 Jul 27; Vol. 39 (14), pp. 2594-2601. Date of Electronic Publication: 2020 Apr 24.
DOI: 10.1021/acs.organomet.0c00167
Abstrakt: The reaction of coordinatively unsaturated Co(II) PCP pincer complexes with nitric oxide leads to the formation of new, air-stable, diamagnetic mono nitrosyl compounds. The synthesis and characterization of five- and four-coordinate Co(III) and Co(I) nitrosyl pincer complexes based on three different ligand scaffolds is described. Passing NO through a solution of [Co(PCP NMe - i Pr)Cl], [Co(PCP O - i Pr)Cl] or [Co(PCP CH2 - i Pr)Br] led to the formation of the low-spin complex [Co(PCP- i Pr)(NO)X] with a strongly bent NO ligand. Treatment of the latter species with (X = Cl, Br) AgBF 4 led to chloride abstraction and formation of cationic square-planar Co(I) complexes of the type [Co(PCP- i Pr)(NO)] + featuring a linear NO group. This reaction could be viewed as a formal two electron reduction of the metal center by the NO radical from Co(III) to Co(I), if NO is counted as NO + . Hence, these systems can be described as {CoNO} 8 according to the Enemark-Feltham convention. X-ray structures, spectroscopic and electrochemical data of all nitrosyl complexes are presented. Preliminary studies show that [Co(PCP NMe - i Pr)(NO)] + catalyzes efficiently the reductive hydroboration of nitriles with pinacolborane (HBpin) forming an intermediate {CoNO} 8 hydride species.
Competing Interests: The authors declare no competing financial interest.
(Copyright © 2020 American Chemical Society.)
Databáze: MEDLINE
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