Metal-pyrimidine interaction: synthesis and crystal structure of a cadmiumcomplex of trimethoprim ([CdBr2(TMP)(2)(H2O)(2)]center dot H2O, TMP = trimethoprim)

The crystal structure of a cadmium complex of trimethoprim ([CdBr2(TMP)(2)( H2O)(2)] . H2O, TMP = trimethoprim) has been determined from X-ray diffract ion data using MoK alpha radia tion. The crystals are monoclinic, C2/c, wit h a = 7.7811(11), b = 15.439(3) c = 29.645(6)Angstrom, beta = 97.23(2)degre es and Z = 4. Trimethoprim (2,3-diamino(3',4',5'trimethoxybenzyl)pyrimidine ) acts as a monodentate ligand. Cadmium is coordinated to N(1) atoms of two trimethoprim moieties. The octahetral coordination geometry around cadmium is completed by two Br-ions and two water molecules. The complex has a two -fold axis coinciding with a crystallographic two-fold axis. There is an in terligand hydrogen bond between the bromide ion and the 2-amino group of th e pyrimidine.