The following complexes were prepared by reacting uric acid (uaH(2)) w
ith 3d metal(II) perchlorates in non-aqueous media: trans-[Mn(uaH)(2)(
OH2)(4)], octahedral, and [Co-(uaH)(2)(OH2)(2)], tetrahedral, both inv
olving O(8)-bound hydrogenurate; [Cu(ua)(OH2)(3)], tetrahedral, with t
he urate dianion binding via a ring nitrogen; and [Ni-2(uaH)(2)-(uaH(2
))(ClO4)(2)(H2O)(3)], formulated as a pentacoordinated linear polymetr
ic species, involving bidentate bridging hydrogenurate, binding throug
h O(8) and a ring nitrogen.