A Novel [FeFe] Hydrogenase Model with a (SCH2)2P═O Moiety
By Almazahreh, Laith R.; Apfel, Ulf-Peter; Imhof, Wolfgang; Rudolph, Manfred; Görls, Helmar; Talarmin, Jean; Schollhammer, Philippe; El-khateeb, Mohammad & Weigand, Wolfgang
Published in Organometallics
2013
Abstract
A novel [FeFe]-hydrogenase model complex containing phosphine oxide in the dithiolato ligand, namely [Fe2(CO)6][(μ-SCH2)2(Ph)P�O] (1), has been synthesized and characterized. Complex 1 was prepared via the reaction of equimolar quantities of (μ-LiS)2Fe2(CO)6 and O�P(Ph)(CH2Cl)2. The protonation properties of complex 1 have been investigated by monitoring the changes in IR (in the ν(CO) region) and 31P 1H NMR spectra upon addition of pyridinium tetrafluoroborate, [HPy][BF4], and HBF4·Et2O, suggesting protonation of the P�O functionality. In addition, high-level DFT calculations on the protonation sites of complex 1 in CH2Cl2 have been performed and support our experimental observations that the P�O unit is protonated by HBF4·Et2O. Cyclic voltammetric experiments on complex 1 showed an anodic shift of the oxidation peak upon addition of HBF4·Et2O, suggesting a CE process.