Chromous hydrazine sulfate.

The title compound, catena-poly[dihydraziniochromium(II)-di-mu-sulfato-O:O'], [Cr(N2H5)2(SO4)2], was studied at 100 K and contains chains of chromium(II) ions linked by pairs of sulfate anions and coordinated to hydrazinium ions. The unique Cr atom lies on an inversion centre. All five H atoms were experimentally located and are involved in hydrogen bonding to O atoms of the sulfate groups.