Syntheses,crystal structures,and antibacterial activities of manganese(III), nickel(II), and copper(II) complexes containing a tetradentate Schiff base

Three new mononuclear Schiff-base complexes, namely Mn(L)Cl] (1), Ni(L)] (2), and Cu(L)] (3), where L?=?anion of N,N′-bis(2-hydroxybenzophenylidene)]propane-1,2-diamine, have been synthesized by reacting equimolar amounts of the respective metal chloride and the tetradentate Schiff base, H₂L, in methanol. The complexes have been characterized by microanalytical, spectroscopic, single-crystal X-ray diffraction, and other physicochemical studies. Structural studies reveal that 1 adopts a distorted square-pyramidal geometry whereas 2 and 3 are isotypic with distorted square-planar geometries. The antibacterial activities of 1–3 along with their Schiff base have been tested against some Gram(+) and Gram(?) bacteria.