SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF A CU-II-THEOPHYLLINE COMPLEX- [CU(THEO)(2) (H2O)(3)]CENTER-DOT-2H(2)O

The complex [Cu-II (theo)(2)(H2O)(3)].2H(2)O (theo = theophylline) was obtained from aqueous solution. The crystals belong to the monoclinic system, space group P2(1)/n, and are reflection twins about the (001) face. The structure was solved using data from a twinned crystal and refined to final R and R(W) values of 0.069 and 0.064, respectively. C opper has a square-pyramidal coordination with two thee molecules coor dinating through N(7) at equatorial positions. The remaining sites are occupied by water molecules. O(6) of one of the thee molecules is at the other axial site at a longer distance of 3.18 Angstrom. This could lead to an alternate (4+1+1) octahedral coordination geometry for Cu- II. The packing is stabilized by stacking interactions between the the ophylline moieties at an average separation of 3.46 Angstrom.