Pecak, J., Eder, W., Stöger, B., Realista, S., Martinho, P. N., Calhorda, M. J., Linert, W., & Kirchner, K. (2020). Synthesis, Characterization, and Catalytic Reactivity of {CoNO}8 PCP Pincer Complexes. Organometallics, 39(14), 2594–2601. https://doi.org/10.1021/acs.organomet.0c00167
E163-01-2 - Forschungsgruppe Koordinationschemie und bio-anorganische Chemie E057-04 - Fachbereich Röntgenzentrum E163-01-1 - Forschungsgruppe Organometallische Chemie und Katalyse
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Journal:
Organometallics
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ISSN:
0276-7333
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Date (published):
2020
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Number of Pages:
8
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Publisher:
AMER CHEMICAL SOC
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Peer reviewed:
Yes
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Keywords:
Inorganic Chemistry; Physical and Theoretical Chemistry; Organic Chemistry
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Abstract:
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(PCPNMe-iPr)Cl], [Co(PCPO-iPr)Cl] or [Co(PCPCH2-iPr)Br] led to the formation of the low-spin complex [Co(PCP-iPr)(NO)- X] with a strongly bent NO ligand. Treatment of the latter species with (X = Cl, Br) AgBF4 led to chloride abstraction and formation of cationic square-planar Co(I) complexes of the type [Co(PCPiPr)( 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(PCPNMe-iPr)(NO)]+ catalyzes efficiently the reductive hydroboration of nitriles with pinacolborane (HBpin) forming an intermediate {CoNO}8 hydride species.
