Interactions of metal ions with a 2,4-diaminopyrimidine derivative (trimethoprim): Antibacterial studies

Abstract

The interaction of copper (II), zinc(II) and cadmium(II) with Trimethoprim (2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl) pyrimidine) has been studied. The crystal structures of [Zn(Trim) 2Cl 2] ( 2) and [Cd(Trim)Cl 2(CH 3OH)] n ( 4) are reported. Compound ( 2) exhibits a distorted tetrahedral environment around the metal center and crystallizes in the triclinic space group P1̄ with a=10.2397(6), b=10.4500(6), c=16.3336(16) Å, α=96.141(8), β=106.085(5), γ=96.551(5)° and Z=2. In complex ( 4), the Cd(II) centers are bridged sequentially by two chlorine ions to form infinite chains and present a six-coordinated environment; the compound crystallizes in the monoclinic P2 1/ C space group with a=13.958(5), b=7.532(2), c=18.390(2) Å, α=90, β=97.32(5), γ=90° and Z=4. In both structures the Trimethoprim acts as a monodentate ligand through the pyrimidinic nitrogen N(1) atom. The characterization of the Cu(Trim) 2(CH 3O)(ClO 4) complex through EPR and magnetic measurements suggests a binuclear or polinuclear nature, with bridging methoxo groups. The complexes were screened for their activity against several bacteria, showing activity similar to that of trimethoprim.