METAL-COMPLEXES OF THE CARBONIC-ANHYDRASE INHIBITOR METHAZOLAMIDE (HMACM) - CRYSTAL-STRUCTURE OF THE ZN(MACM)(2)(NH3)(2) - ANTICONVULSANT PROPERTIES OF THE CU(MACM)(2)(NH3)(2)(H2O)

Complexes of Co(II), Cu(II), and Zn(II) with deprotonated methazolamide and ammonia are synthesized and characterized. The complex Zn(macm)(2)(NH3)(2) crystallizes in the monoclinic C2/c space group with a = 13.468(1), b = 6.759(1), c = 23.014(2) Angstrom, beta = 90.27(1), and Z = 4. The structure was refined to R = 0.049 (R(w) = 0.053). The Zn(II) ion is coordinated to two deprotonated sulfonamido nitrogen atoms of the macm(-) ligand and two nitrogen atoms of the ammonia ligands in a distorted tetrahedron. The Zn(macm)(2)(NH3)(2) complex is shown to be a simple model for the methazolamide inhibition of CA. EHMO calculations applied to fractional coordinates of the Zn(macm)(2)(NH3)(2) complex indicate that the atomic orbitals of the Zn do not contribute to HOMO and LUMO of the complex. The characteristics of the Cu(macm)(2)(NH3)(3)(H2O) as an anticonvulsant agent are tested.