The d10 metal chelates derived from Schiff base ligands having silane:: Synthesis, characterization, and antimicrobial studies of cadmium(II) and zinc(II) complexes

The new Zn(II) and Cd(II) complexes were synthesized with the bidentate Schiff base ligands containing the silane group 4-{[(3-trimethoxysilanepropyl)imino]methyl}benzene-2,4-diol ((LH)-H-1) and 4-{[(3-triethoxysilanepropyl)imino]methyl}benzene-2,4-diol ((LH)-H-2), which were prepared by the reaction of 2,4-dihydroxybenzaldehyde with 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane respectively. The syntheses of Zn-II and Cd-II chelates of these Schiff bases have been done by the precipitation technique. The synthesized metal complexes were further characterized by elemental analysis, molar conductance measurements, infrared spectra, and UV-visible spectral data. Based on these characterizations, the metal complexes of Zn-II and Cd-II may be formulated as [M(L-I)(2)] or [M(L-2)(2)] where M = Zn, Cd. The Zn-II and Cd-II metal complexes are formed by the coordination of N, O atoms of the ligands. The Molar conductance values of the Zn-II and Cd-II complexes of the bidentate Schiff base ligands indicate their non-ionic character. The antimicrobial properties of Zn-II and Cd-II complexes against Klebsiella pneumoniae, Micrococcus luteus, Enterobacter cloacae, Bacillus megaterium, and Mycobacterium smegmatis and two fungi, namely Kluyveromyces marxianus and Rhodotorula rubra are reported. (1) [Cd(L-1)(2)] and (2) [Zn(L-2)(2)] metal chelates exhibited high activity against the Rhodotorula rubra.