An ion pair formed by protonated Fe(cp*py)2 and the octanuclear cluster U8Cl24O4(cp*py)2 [cp*py is tetramethyl-5-(2-pyridyl)cyclopentadiene].

In bis[1,1',2,2',3,3',4,4'-octamethyl-5-(2-pyridinio)-5'-(2-pyridyl)ferrocene] di-mu(3)-chloro-hexadeca-mu(2)-chloro-hexachlorodi-mu(4)-oxo-di-mu(3)-oxo-bis[(eta(5),kappaN)-1,2,3,4-tetramethyl-5-(2-pyridyl)cyclopentadienyl]octauranium(IV) dichloromethane tetrasolvate, [Fe(C(14)H(17)N)(C(14)H(16)N)](2)[U(8)Cl(24)O(4)(C(14)H(16)N)(2)].4CH(2)Cl(2), (I), two protonated Fe(cp*py)(2) units [cp*py is tetramethyl-5-(2-pyridyl)cyclopentadiene] form an ion pair with the dianionic centrosymmetric cluster U(8)Cl(24)O(4)(cp*py)(2). The latter is the highest nuclearity assemblage in the chemistry of uranium (non-uranyl) compounds reported to date.