Synthesis, characterization and biological activity of tin(IV) macrocyclic complexes derived from 1,2-diphenylethane-1,2-dione dihydrazone

The reaction of dimethyl tin(IV) dichloride with 1,2-diphenylethane-1,2-dione dihydrazone in the presence of metal ions in a 2:2:1 molar ratio resulted in the isolation of macrocyclic complexes of the types [MLX2Sn(CH3)2] and [CuLSn(CH3)2]X2 (M=Mn(II), Co(II), Ni(II) and Zn(II); X=Cl or NO3). In both the cases, complexes exhibit identical patterns suggesting them to be isostructural. The cyclization has been identified on the basis of IR, 1H NMR and 119Sn NMR studies, and the overall geometry of the complexes has been assigned by the data obtained from elemental analyses, electron paramagnetic resonance and electronic spectral studies, and conductivity and magnetic susceptibility measurements. Except for the complexes of copper, which are square planar, all other complexes have octahedral structures. All the synthesized tin(IV) macrocyclic metal complexes were tested for their in vitro anti-fungal activity against some fungal strains, namely Aspergillus fumigatus and Trichoderma harzianum