An unexpected leading role for [Fe2(CO)6(μ-pdt)] in our understanding of [FeFe]-H2ases and the search for clean hydrogen production

Mono- and Dinuclear Carbonyl Dithiolene Complexes Related to the [FeFe]-Hydrogenases

“…Relatively few examples of di-iron complexes [Fe2(CO)6−xLx(µ-dithiolene)] have been reported [7][8][9][10][11][12]. The hexacarbonyl precursors can be prepared following various pathways, which have been previously reported in the literature [1][2][3][4]11]. The substitution of carbonyl groups by phosphanes, through photochemical, thermal or electrochemical activation, allows us to prepare monosubstituted [Fe2(CO)5L(µ-dithiolene)] and symmetrically disubstituted [Fe2(CO)4L2(µ-dithiolene)] derivatives (one CO being replaced at each iron atom).…”

“…Complex 5: IR (CH 2 Cl 2 , cm −1 ): ν(CO), bands overlapped with those of 2. 1 H NMR (CDCl 3 , δ, ppm): 7.68-7.36 (m, 30H, Ph), 3.17 (s, 6H, CH 3 ). 31 P-{ 1 H} NMR (CDCl 3 , δ, ppm) 57.5 (s).…”

“…Complex 3: IR (CH 2 Cl 2 , cm −1 ): ν(CO) 2061 (s), 2008 (vs), 1989 (s), 1955 (w), 1717 (w, CO 2 Me). 1 H NMR (CDCl 3 , δ, ppm): 3.80 (d, J = 12.0Hz, 9H, P(OMe) 3 ), 3.66 (s, 6H, CO 2 Me). 31 P-{ 1 H} NMR (CDCl 3 , δ, ppm): 172.1 (s).…”

“…Complex 6: IR (CH 2 Cl 2 , cm −1 ):ν(CO) 2036 (s), 1988 (s). 1 H NMR (CDCl 3 , δ, ppm): 3.93 (s, 6H, CO 2 Me), 3.45 (d, J = 12.0Hz, 9H, P(OMe) 3 ). 31 P-{ 1 H} NMR (CDCl 3 , δ, ppm): 168.2 (s).…”

“…The chemistry of carbonyl dithiolato di-iron complexes [Fe 2 (CO) 6−x L x (µ-dithiolato)] has attracted a lot of attention during the two last decades in reason of the resemblance of such compounds with the active site of [FeFe]-hydrogenases (H-cluster) (Scheme 1a) and in view to obtain efficient bioinspired non-noble metal electrocatalysts for the reversible H + /H 2 conversion [1][2][3][4][5]. A wide number of di-iron systems with various combinations of thiolate bridges and terminal ligands have been studied in order to tune the electronic and steric properties of the dinuclear site as well as to functionalize the second sphere of coordination with non-innocent functionalities (redox and proton relays) [6].…”