Inorganic Chemistry

Magnesium-Stabilised Transition Metal Formyl Complexes: Structures, Bonding, and Ethenediolate Formation



Herein we report the first comprehensive series of crystallographically characterised transition metal formyl complexes. In these complexes, the formyl ligand is trapped as part of a chelating structure between a transition metal (Cr, Mn, Fe, Co, Rh, W, and Ir) and a magnesium (Mg) cation. Calculations suggest that this bonding mode results in significant oxycarbene-character of the formyl ligand. Electron-rich late-transition metal complexes have the highest oxycarbene-character to the bonding and are the most stable in solution. Further reaction of a heterometallic Cr---Mg formyl complex results in a rare example of C–C coupling and formation of an ethenediolate complex. These results show that well-defined transition metal formyl complexes are potential intermediates in the homologation of carbon monoxide.


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Supplementary material

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Supporting information
Supporting Information. X-ray crystallographic data for 3a-h and 4a are available from the Cambridge Crystallographic Data Centre (CCDC 2116002 - 2116010) as a .cif file, full details of the experiments and calculations are available as a .pdf