Hexaaquanickel(II) disulfato(1,4,8,11-tetraazacyclotetradecane)nickelate(II) dihydrate.

The title compound, [Ni(H(2)O)(6)][Ni(SO(4))(2)(C(10)H(24)N(4))].2H(2)O, is an unusual compound in that it is composed of a hexaaqua complex, formally a dication, and a mixed-donor complex (four N and two O atoms), formally a dianion, with substantial charge separation between the two nickel centres (6.536 A).