(5-Fluoro-2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidin-1-ido-κ N 1 )(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ 4 N )zinc(II) perchlorate.

In the structure of the title complex, [Zn(C 4 H 2 FN 2 O 2 )(C 10 H 24 N 4 )]ClO 4 , the zinc(II) ion forms coordination bonds with the four nitro-gen atoms of cyclam (1,4,8,11-tetra-aza-cyclo-tetra-decane or [14]aneN4) as well as with the nitro-gen atom of a deprotonated 5-fluoro-uracil ion (FU - ). Cyclam adopts a trans -I type conformation within this structure. The coordination structure of the zinc(II) ion is a square pyramid with a distorted base plane formed by the four nitro-gen atoms of the cyclam. FU - engages in inter-molecular hydrogen bonding with neighboring FU - mol-ecules and with the cyclam mol-ecule.