CRYSTAL-STRUCTURE OF -2,2'-BIPYRIDINE)IRON(II)BIS(HEXAFLUOROPHOSPHATE), SOLVATE WITH N-METHYL-2-PYRROLIDONE

The crystal study of tris y-2,2'-bipyridine)iron(II)bis(hexafluorophos phate) (crystal solvate with N-methyl-2-pyrrolidone) was performed at 295 K. The crystals aretriclinic, a = 11.721(4), b = 12.864(6), c = 15 .664(7) Angstrom, alpha = 77.14(4), beta = 85.03(3), gamma = 81.76(3)d egrees, space group <P(1)over bar>, Z = 2, R = 0.0679 for 4694 reflect ions. The average Fe-N distance of 1.967 Angstrom agrees well with tho se observed in other tris (2,2-bipyridine) complexes of hexacoordinate d Fe(II) with a large low-spin fraction. A small difference of the ind ividual Fe-N distances in the dication (which are shorter for one of t he bipyridine ligands) may be explained by crystal packing effects. A very specific orientation of dications [Fe(DMO-bpy)(3)](2+) in the cry stal is worthy of note (the vector of one of the moieties N...(Fe)...N of the dication coincides in fact with direction [011] of the crystal ). The possible interaction of the trication of tris (4,4'-dimethoxy-2 ,2'-bipyridine) iron(III) with the active site of glucose oxidase (i.e . the metal complex acting as an oxidant/electron-transfer mediator) i s discussed.