Protonolysis of Fe–C bonds of a diiminopyridineiron(II) dialkyl complex by acids of different strengths: Influence of monoanionic ligands on the spectroscopic properties of diiminopyiridine-FeY2 complexes

•The reaction of [FeR2(MesBIP)] complexes with protic acids is investigated.•A series of complexes of type [FeY2(MesBIP)] have been isolated and characterised.•The crystal structures of bis(aryloxide) and bis-triflato derivatives are reported.•The energy of the visible band of [FeY2(MesBIP)] correlates with the basicity of Y.•Some 1H NMR signals are useful for complex identification.

The reaction of the dialkyliron complex [Fe(CH2SiMe3)2(MesBIP)] (MesBIP = 2,6-bis((N-mesityl)acetimidoyl)pyridine) with protic acids (HY) of different strengths (Y = C6F5O, CF3CO2, Cl, CF3SO3) invariably leads to the cleavage of both Fe–C bonds, independent of the Fe/HY ratio used (either 1:2 or 1:1), affording the corresponding complexes [FeY2(MesBIP)]. Relevant spectroscopic features of these compounds, such as paramagnetic 1H NMR shifts and UV–Vis absorption bands, exhibit a marked dependence on the nature of Y.

Graphical abstractThe reaction of the dialkyliron complex [Fe(CH2SiMe3)2(MesBIP)] (MesBIP = 2,6-bis(N-mesityl)acetimidoyl)pyridine) with protic acids HY of different strengths leads to the corresponding complexes [FeY2(MesBIP)]. The influence of the anionic Y ligands on relevant spectroscopic features of these complexes is discussed.Figure optionsDownload full-size imageDownload as PowerPoint slide