Synthesis and characterisation of three diiron tetracarbonyl complexes related to the diiron centre of [FeFe]-hydrogenase and their protonating, electrochemical investigations†
Abstract
The synthesis, characterisation of three diiron tetracarbonyl complexes, [Fe2(SCH2)2C(Me)(CH2OR)(PNP)(CO)4] (R = H and PNP = L11: 2; R = H and PNP = L22: 3; R = Ts and PNP = L11: 4) as models for the diiron sub-unit of [FeFe]-hydrogenase are described, where OTs, L11 and L22 are toluenesulfonate, (Ph2P)2NCH2(2-C5H4N) and (Ph2P)2NCH2Ph, respectively. These complexes are fully characterised and the structure of complex 4 is crystallographically determined. Protonation of these complexes with HBF4·Et2O is probed by using infrared and NMR spectroscopies which reveals that no