Models of the iron-only hydrogenase: Synthesis and protonation of bridge and chelate complexes [Fe2(CO)4{Ph2P(CH2)nPPh2}(μ-pdt)] (n = 2–4) – evidence for a terminal hydride intermediate

Phenyl-functionalized diiron diselenolato complexes with intra- or inter-molecular bridging bidentate phosphine ligands

“…Complex 3 contains two diiron propanediselenolato cores which are connected together by a dppf ligand, similar to the previously reported diiron diselenolato complex [Fe 2 (lSeC 3 H 5 CH 3 Se-l)(CO) 5 ] 2 (l-dppe) [32] and diiron dithiolato complexes [Fe 2 (l-SCH 2 OCH 2 S-l)(CO) 5 ] 2 [(g 5 -Ph 2 PC 5 H 4 ) 2 Fe] [34], [Fe 2 (l-SCH 2 OCH 2 S-l)(CO) 5 ] 2 [(g5-Ph 2 PC 5 H 4 ) 2 Ru] [35], [(l-SCH 2 ) 2 CHC 6 H 5 Fe 2 (CO) 5 ] 2 (l, j 1 , j 1 -dppf) [23] and [(l-SCH 2 ) 2 NPhFe 2 (CO) 5 ] 2 [(g 5 -Ph 2 PC 5-H 4 ) 2 Fe] [36]. Each phosphine of the dppf ligand occupies an axial position of the square pyramidal coordination spheres of Fe2 and Fe2A, in accord with diiron dithiolato complexes with an inter-molecular bridging diphosphine ligand, such as {[(l-SCH 2 ) 2 CH 2 ]Fe 2 (CO) 5 } 2 (dppe) [37] and {Fe 2 (CO) 5 [(l-SCH 2 ) 2 CH 2 ]} 2 [(l, j 1 , j 1 -Ph 2 PCH 2 N(nPr)CH 2 PPh 2 ] [38]. Complex 3 is centrosymmetric with Fe3 as the symmetry center, like the reported diiron dithiolato analog {Fe 2 (CO) 5 [(l-SCH 2 ) 2 CH 2 ]} 2 [(g 5 -Ph 2 PC 5 H 4 ) 2 Fe] [39].…”

Binuclear Copper(I) Borohydride Complex Containing Bridging Bis(diphenylphosphino) Methane Ligands: Polymorphic Structures of [(µ2-dppm)2Cu2(η2-BH4)2] Dichloromethane Solvate

“…Additionally, stretching vibration of CuHBH cycle is a unique feature of {M(η 2 -BH 4 )} complexes [52,63]. Analysis of the data for copper(I) tetrahydroborate complexes shows that the 11 could not be accurately determined [63]. The XRD analysis of monocrystals obtained for this copper(I) tetrahydroborate compound revealed it is a binuclear complex bearing two dppm ligands bridging two {Cu(η 2 -BH 4 )} fragments.…”

“…Such compounds are of great interest due to their catalytic activity including the transformation of small molecules on metal centres [8,9], they can also be used as synthetic models of enzyme action [10][11][12].…”

A comparative study of the electrochemical and proton-reduction behaviour of diphosphine-dithiolate complexes [M2(CO)4(μ-dppm){μ-S(CH2) n S}] (M = Fe, Ru; n = 2, 3)

“…Diphosphines have been widely used in this context and can either bridge the diiron centre or chelate to one end, bridging complexes, [Fe 2 (CO) 4 -(l-diphosphine)(l-dithiolate)] being thermodynamically stable with respect to isomeric chelate complexes [Fe 2 (CO) 4 -(j 2 -diphosphine)(l-dithiolate)]. Consequently a large number of diphosphine-bridged diiron-dithiolate complexes have been reported [23][24][25][26][27][28][29][30][31][32] but surprisingly little attention has been paid to their proton-reduction chemistry [27][28][29][30][31][32] even though some, for example [Fe 2 (CO) 4 (l-dppf)(l-pdt)] (dppf = 1,1 0 -bis(diphenylphosphino)ferrocene), have been shown to be efficient proton-reduction catalysts [29]. Similarly, given the large number of diiron complexes tested as proton-reduction catalysts, related diruthenium complexes have not been widely studied [53][54][55][56].…”

“…Consequently a large number of diphosphine-bridged diiron-dithiolate complexes have been reported [23][24][25][26][27][28][29][30][31][32] but surprisingly little attention has been paid to their proton-reduction chemistry [27-32] even though some, for example [Fe 2 (CO) 4 (l-dppf)(l-pdt)] (dppf = 1,1 0 -bis(diphenylphosphino)ferrocene), have been shown to be efficient proton-reduction catalysts [29]. Similarly, given the large number of diiron complexes tested as proton-reduction catalysts, related diruthenium complexes have not been widely studied [53][54][55][56].…”