Bis(tetraphenylphosphonium) bis[cis-1,2-bis(methoxycarbonyl)ethylene-dithiolato-κ2 S,S′]nickelate(II) and bis(tetraphenylphosphonium) bis[cis-1,2-bis(methoxycarbonyl)ethylene-dithiolato-κ2S,S′]nickelate(III) iodide

The crystal structures of the title compounds, (C24H20P)(2) [Ni(C-6 H6O4S2)(2)], (I), and (C24H20P)(2) [Ni(C6H6O4S2)(2)]I, (II), in the diamagnetic reduced (2-) and paramagnetic oxidized (1-) states, are reported at 200 and 293 K, respectively. In both compounds, the Ni atom lies on an inversion centre and the NiS4 coordination is thus required to be exactly planar. In the diamagnetic complex, (I), the Ni-S distances are 2.1818 (7) and 2.1805 (6) Angstrom, while they are 2.1481 (6) and 2.1392 (5) Angstrom in the paramagnetic complex, (II). This results from both the different complex core oxidation states and the different conformations of the methoxycarbonyl groups.