Structures, luminescence, and antibacterial studies of two transition metal complexes involving Schiff bases

Two new transition metal complexes of Schiff bases, [Pd-2(L1)(2)Cl-2] (1) and [Zn(L2)(2)] (2), [L1=N-(4-fluorobenzylidene)-2,6-diisopropylbenzenamine and L2=2,4-dibromo-6-((E)(mesitylimino)methyl)phenol], have been synthesized solvothermally and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, powder X-ray diffraction, UV-vis absorption spectra, and single-crystal X-ray diffraction. Complex 1 is a -chloro-bridged dinuclear cyclometallated Pd(II) complex, whereas 2 is mononuclear with the Zn-II tetrahedrally coordinated by two L2. Both 1 and 2 display photoluminescence in the solid state at 298K (fluorescence lifetimes =22.516ns at 468nm for 1, =3.697s at 490nm for 2). These Schiff bases and their metal compounds have been screened for antibacterial activity against several bacteria, and the results are compared with the activity of penicillin.