Structure dependence on redox state and charge in [Fe4(μ3-S4)-(η-C5H5)4]m[M(mnt)2]n (M = Ni or Pt, m, n=1 or 2)

The complex salts [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)](m)[M(mnt)(2)](n) {M=Ni, n=2, m=1 1; n=1, m=1 2 or 2 3: M=Pt, n=2, m=1 4; n=1, m=1 5 or 2 6; mnt=S2C2(CN)(2)} have been synthesized by stoichiometric reactions between [NEt4](n)[M(mnt)(2)] (n=1 or 2, M=Ni or Pt) and [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)][PF6](n) (n=1 or 2); the salts 2-6 have been structurally characterised. The molecular structures of the [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)](z+) (z=1 or 2) cations and the [M(mnt)(2)](z-) (M=Ni or Pt, z=1 or 2) anions show mean Fe . . . Fe and M-S distances characteristic of z. The isostructural salts [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)](2)[M(mnt)(2)] (M=Ni 3 or Pt 6) comprise two monocations and one dianion; the planar anions, which form a ruffled ribbon arrangement, are interleaved by the near-spherical cations. The structure of [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)][Pt(mnt)(2)](2), 4, with two monoanions and one dication, has face-to-face metal-metal pairs of [Pt(mnt)(2)](-) ions separated by individual [Pt(mnt)(2)](-) units, leading to anion layers interleaved by layers of cations. Salts 2 and 5 have very different structures. The nickel complex [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)][Ni(mnt)(2)] 2 comprises dications and dianions whereas the platinum complex [Fe-4(mu (3)-S)(4)(eta -C5H5)(4)][Pt(mnt)(2)] 5 has monocations and monoanions. In salt 2 the dianions are well separated while in 5 the monoanions are weakly dimerised.