Relationships between 57Fe NMR, Mössbauer parameters, electrochemical properties and the structures of ferrocenylketimines

A comparative study of the electrochemical properties, 57Fe NMR and Mössbauer spectroscopic data of compounds [(η5-C5H5)Fe{(η5-C5H4)–C(R1)double bond; length as m-dashN–R2}] {R1 = H, R2 = CH2–CH2OH (1a), CH(Me)–CH2OH (1b), CH2C6H5 (1c), C6H4–2Me (1d), C6H4–2SMe (1e) or C6H4–2OH (1f) and R1 = C6H5, R2 = C6H4–2Me (2d)} is reported. The X-ray crystal structure of [(η5-C5H5)Fe{(η5-C5H4)–CHdouble bond; length as m-dashN–C6H4–2OH}] (1f) is also described. Density functional theoretical (DFT) studies of these systems have allowed us to examine the effects induced by the substituents of the “–C(R1)double bond; length as m-dashN–R2” moiety or the aryl rings (in 1d–1f) upon the electronic environment of the iron(II) centre.