A trinuclear Fe-Fe-Ni complex formed by ligand reshuffling.

The title complex, dicarbonyl-3κ(2)C-(µ(3)-3,6-dimethyl-3,6-diaza-octane-1,8-dithiol-ato-1:2:3κ(7)S:S,N,N',S':S,S')(µ(2)-3,6-di-methyl-3,6-diaza-octane-1,8-dithiol-ato-1:2κ(5)S,N,N',S':S)-1,2-diiron(II)-3-nickel(0) [Fe(2)Ni(C(8)H(18)N(2)S(2))(2)(CO)(2)], is the second example showing M(µ-SR)(2)Ni(0)(CO)(2) coordination (M = any metal atom). Both Fe(II) ions are five-coordinated in distorted trigonal-bipyramidal geometries by two N atoms and three S atoms. The Ni atom is four-coordinated in a distorted tetra-hedral geometry by two S atoms and two carbonyl ligands. One of the 3,6-dimethyl-3,6-diaza-octane-1,8-dithiol-ate ligands is disordered, the major component having a refined occupancy of 0.873 (2). The Fe⋯Fe distance is 3.0945 (3)Å and the Ni⋯Fe distance is 2.8505 (3) Å.

Synthesis and structure of analogues for the Ni-Fe site in hydrogenase enzymes.

Dithiolate bridging Ni-Fe complexes [(dppe)Ni(II)(mu-SEt)(2)Fe(II)(CN)(2)(CO)(2)](6) and [(dppe)Ni(II)(mu-pdt)Fe(II)(CN)(2)(CO)(2)] [dppe = 1,2-bis(diphenylphosphino)ethane and pdt = 1,3-propanedithiolate] have been synthesized and structurally characterized as structural analogues of the active site of Ni-Fe hydrogenase enzymes. The synthesis starts from key intermediate fac-[Fe(CN)(2)(CO)(3)I](-). [(dppe)Ni(II)(mu-SEt)(2)Fe(II)(CN)(2)(CO)(2)](6), which features a near-planar diethanethiolate-bridged Ni-Fe rhomb, and the arrangement of 2CN(-) ligands is cis to each other. In contrast, [(dppe)Ni(II)(mu-pdt)Fe(II)(CN)(2)(CO)(2)] shows a much more folded NiS(2)Fe rhomb, a short Ni-Fe distance, trans 2CN(-) ligands, and a semibridging CN(-) between Ni and Fe.

Oxidation of carbon monoxide in basic solution catalyzed by nickel cyano carbonyls under ambient conditions and the prototype of a CO-powered alkaline fuel cell.

CO reduces nickel(2+) cyanides in basic solution to form tetrahedral Ni(0)(CN)(CO)3(-) or Ni(0)(CN)2(CO)2(2-). Both nickel(0) complexes can be oxidized back to nickel(2+) cyanide/hydroxide so that they behave as CO oxidation catalysts in basic solution. A primitive fuel cell was constructed to demonstrate the feasibility of a CO-powered fuel cell.

[Co(I)(CN)2(CO)3]-, a new discovery from an 80-year-old reaction.

A systematic study of the 80-year-old simple and fundamental reaction of cobalt(II) salt with cyanide under one atmosphere CO was carried out and two novel Co(I) complexes were isolated in the absence of hydroxide. These complexes are the first structurally characterized mixed cobalt CO-CN(-) compounds.