Diiron species containing a cyclic P^Ph₂N^Ph₂diphosphine related to the [FeFe]H₂ases active site

Abstract

A new dissymmetrically disubstituted diiron dithiolate species, [Fe(2)(CO)(4)(κ(2)-P(Ph)(2)N(Ph)(2))(μ-pdt)] (pdt = S(CH(2))(3)S), was prepared by using a flexible cyclic base-containing diphosphine, 1,3,5,7-tetraphenyl 1,5-diaza-3,7-diphosphacyclooctane (P(Ph)(2)N(Ph)(2) = {PhPCH(2)NPh}(2)). Preliminary investigations of proton and electron transfers on the diiron system have been done.

Bioinspired Hydrogenase Models: The Mixed-Valence Triiron Complex [Fe3(CO)7(μ-edt)2] and Phosphine Derivatives [Fe3(CO)7–x(PPh3)x(μ-edt)2] (x = 1, 2) and [Fe3(CO)5(κ2-diphosphine)(μ-edt)2] as Proton Reduction Catalysts

“…40 In light of the work described here, it seems probable that this results from the reaction of small amounts of [Fe 3 (CO) 7 (μ-pdt) 2 ] in the diiron starting material.…”

Models of the iron-only hydrogenase enzyme: structure, electrochemistry and catalytic activity of Fe2(CO)3(μ-dithiolate)(μ,κ1,κ2-triphos)

“…The active site of these (Chart 1a) feature a diiron centre spanned by a bridging dithiolate group further ligated by three carbonyls and two cyanides, and being linked to a [4Fe-4S] cluster via one of the thiolate groups of the latter. Over the past 20 years there has been considerable effort expended into the development of [FeFe]-hydrogenase biomimics [2], however, somewhat surprisingly given the tricarbonyl nature of the enzymes active site, complexes based on an Fe2(CO)3L3(-dithiolate) framework have been relatively underexplored [3][4][5][6][7][8][9][10][11][12][13][14][15][16], especially in comparison with those of the type Fe2(CO)4L2(-dithiolate) [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Rauchfuss and co-workers have studied complexes of the type Fe2(CO)3( 1 -PR3)( 2dppv)(-dithiolate) (R = Me, i Pr, dppv = cis-1,2-bis(diphenylphosphino)ethene)) [6] and Schollhammer and co-workers have prepared and investigated related phosphite, Fe2(CO)3{ 1 -P(OMe)3}( 2 -dppe)(-pdt) [15], and 1,10-phenanthroline, Fe2(CO)3( 1 -PPh3)( 2 -1,10-phen)(pdt) [16], complexes (Chart 1b-d).…”

Synthesis, characterization and DFT studies of 1, 1′-Bis(diphenylphosphino)ferrocene substituted diiron complexes: Bioinspired [FeFe] hydrogenase model complexes

“…Various models of the active site of the [FeFe] H 2 ases have been designed and studied in order to get a detailed picture on the functional activity of these enzymes. [6][7][8][9] Though a large number of mono-and bidentate phosphine substituted model complexes have been reported, [10][11][12][13][14][15][16][17][18][19][20][21] there are only very few examples known in which the carbonyl ligand on the Fe-atom has been substituted by ferrocene phosphines. A * For correspondence few such examples are: [Fe (µ-pdt)(CO) 5 ] 2 [η 5 -Ph 2 PC 5 H 4 ) 2 Fe], 22 [Fe 2 (µ-SCH 2 XCH 2 S-µ)(CO) 5 ] 2 [η 5 -Ph 2 PC 5 H 4 ) 2 Fe] (X = O, S), 23,24 which contain the bidentate phosphine ligand 1, 1 24,25 and [Fe 2 (µ-pdt)(µdppf)CO) 4 ].…”