Treatment of -MeFe(PMe) with di-1,2-(-2-(pyridin-2-yl)vinyl)benzene ((bdvp)H), a tetradentate ligand precursor, afforded (bdvp)Fe(PMe) (-PMe) and 2 equiv. CH, C-H bond activation. Similar treatments with tridentate ligand precursors PhCH[double bond, length as m-dash]NCH(-CH[double bond, length as m-dash]CHPh) ((pipp)H) and PhCH[double bond, length as m-dash]N(2-CCMe-Ph) ((pipa)H) under dinitrogen provided -(pipp)Fe(PMe)N () and -(pipvd)Fe(PMe)N (), respectively; the latter one C-H bond activation, and a subsequent insertion of the alkyne into the remaining Fe-Me bond. All three Fe(ii) vinyl species were protonated with H[BAr ] to form the corresponding Fe(iv) alkylidene cations, [(bavp)Fe(PMe)][BAr ] (-PMe), [(piap)Fe(PMe)][BAr ] (), and [(pipad)Fe(PMe)][BAr ] (). Mössbauer spectroscopic measurements on the formally Fe(ii) and Fe(iv) derivatives revealed isomer shifts within 0.1 mm s, reflecting the similarity in their bond distances.
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| http://dx.doi.org/10.1039/c5sc01268f | DOI Listing |
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