Electronic Structure of a Diiron Complex: A Multitechnique Experimental Study of [(dppf)Fe(CO) 3]+/0 Winkler, Mario Schnierle, Marc Ehrlich, Felix Mehnert, Kim-Isabelle Hunger, David Sheveleva, Alena M. Burkhardt, Lukas Bauer, Matthias Tuna, Floriana Ringenberg, Mark R. van Slageren, Joris Inorganic Chemistry Physical and Theoretical Chemistry Here we explore the electronic structure of the diiron complex [(dppf)Fe(CO)3]0/+ [10/+; dppf = 1,1′-bis(diphenylphosphino)ferrocene] in two oxidation states by an advanced multitechnique experimental approach. A combination of magnetic circular dichroism, X-ray absorption and emission, high-frequency electron paramagnetic resonance (EPR), and Mössbauer spectroscopies is used to establish that oxidation of 10 occurs on the carbonyl iron ion, resulting in a low-spin iron(I) ion. It is shown that an unequivocal result is obtained by combining several methods. Compound 1+ displays slow spin dynamics, which is used here to study its geometric structure by means of pulsed EPR methods. Surprisingly, these data show an association of the tetrakis[3,5-bis(trifluoromethylphenyl)]borate counterion with 1+. American Chemical Society (ACS) 2021 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/41012 Winkler M, Schnierle M, Ehrlich F, et al. Electronic Structure of a Diiron Complex: A Multitechnique Experimental Study of [(dppf)Fe(CO) 3]+/0. Inorganic Chemistry. 2021;60(5):2856-2865. doi:<a href="https://doi.org/10.1021/acs.inorgchem.0c03259">10.1021/acs.inorgchem.0c03259</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1021/acs.inorgchem.0c03259 info:eu-repo/semantics/altIdentifier/issn/0020-1669 info:eu-repo/semantics/altIdentifier/issn/1520-510X info:eu-repo/semantics/closedAccess