Premium
Structural Differences and Redox Properties of Unsymmetric Diiron PDIxCy Complexes
Author(s) -
Hofmann Andreas J.,
Jandl Christian,
Hess Corinna R.
Publication year - 2020
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201901173
Subject(s) - chemistry , ligand (biochemistry) , redox , bimetallic strip , non innocent ligand , metal , cyclic voltammetry , crystallography , linker , mössbauer spectroscopy , electrochemistry , stereochemistry , inorganic chemistry , organic chemistry , electrode , biochemistry , receptor , computer science , operating system
We present two bimetallic iron complexes, [Fe 2 (PDIeCy)(OTf) 4 ] ( 1 ) and [Fe 2 (PDIpCy)(THF)(OTf) 4 ] ( 2 ) coordinated by an unsymmetric ligand. The new ligand, PDIeCy (PDI = pyridyldiimine; e = ethyl; Cy = cyclam), is a variant of the previously reported PDIpCy (p = propyl) ligand, featuring a shorter linker between the two metal coordination sites. The structural and electronic properties of 1 and 2 , both in the solid and solution state, were analyzed by means of X‐ray crystallography, and spectroscopic methods, including 19 F‐NMR. The two ligand platforms yield markedly different diiron structures: the PDIeCy ligand permits formation of a bridged, µ‐OTf complex, while the two iron centers of the PDIpCy‐based 2 remain unconnected, directly, under all conditions examined. Both compounds contain electronically non‐coupled high‐spin ( S = 2) ferrous centers, as established by Mössbauer spectroscopy and magnetic susceptibility studies. Cyclic voltammetry demonstrates the rich redox chemistry of the compounds, involving both ligand and metal‐centered redox processes. Moreover, we synthesized the two‐electron reduced [Fe 2 (PDIeCy)] 2+ form of 1 , which contains the dianionic PDI 2– ligand, and represents a two‐electron charge localized complex.