A μ‐Phosphido Diiron Dumbbell in Multiple Oxidation States. Issue 40 (23rd August 2019)

• Record Type: Journal Article
• Authors: Ghosh, Munmun; Cramer, Hanna H.; Dechert, Sebastian; Demeshko, Serhiy; John, Michael; Hansmann, Max M.; Ye, Shengfa; Meyer, Franc
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 40(2019)
• Page Start: 14349
• Page End: 14356
• Publication Date: 2019-08-23
• Subjects: electronic structure -- iron complexes -- N-heterocyclic carbenes -- phosphido complexes -- redox series; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201908213
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The reaction of the ferrous complex [LFe(NCMe)2 ](OTf)2 (1 ), which contains a macrocyclic tetracarbene as ligand (L), with Na(OCP) generates the OCP − ‐ligated complex [LFe(PCO)(CO)]OTf (2 ) together with the dinuclear μ‐phosphido complex [(LFe)2 P](OTf)3 (3 ), which features an unprecedented linear Fe‐(μ‐P)‐Fe motif and a "naked" P‐atom bridge that appears at δ=+1480 ppm in the 31 P NMR spectrum. 3 exhibits rich redox chemistry, and both the singly and doubly oxidized species 4 and 5 could be isolated and fully characterized. X‐ray crystallography, spectroscopic studies, in combination with DFT computations provide a comprehensive electronic structure description and show that the Fe‐(μ‐P)‐Fe core is highly covalent and structurally invariant over the series of oxidation states that are formally described as ranging from Fe III Fe III to Fe IV Fe IV . 3 –5 now add a higher homologue set of complexes to the many systems with Fe‐(μ‐O)‐Fe and Fe‐(μ‐N)‐Fe core structures that are prominent in bioinorganic chemistry and catalysis. Abstract : The naked truth : Using a macrocyclic tetracarbene ligand scaffold and Na(OCP) as a P‐atom transfer reagent has allowed a diiron complex to be isolated with a "naked" P bridge. The complex exhibits rich redox chemistry, and both the singly and doubly oxidized species could be isolated and fully characterized. The unprecedented linear Fe‐(μ‐P)‐Fe core is highly covalent and is structurally invariant over three oxidation states.