Tetradentate Schiff base ligands. L1= (2Z)-2,2((4-methyl-1,2-phenylene) bis (azoneylidine))) bis (acenaphthylene-1(2H)-one, L2=(2Z,2E)-2,2'-((4-nitro-1,2-phenylene) bis azoneylylidene)) bis azoneylylidene)) bis (acenaphthylen-1(2H)-one, L3= 6.6 (((1E,2E)-acenphthylene -1,2diylidene) bis (azoanylidene)) bis (3-methylaniline), and L4= 6,6'-(acenaphthylene-1,2-diylidene) bis (azoneylyidene)) bis (3-nitroanilin), type (N2O2) and (N4) donor atoms obtained from condensation of acenaphthylenequinone with 4-methyl or nitro-o-phenylenediamine (2:1) and (1:2) (quinone:amine) molar ratio for the first and second type respectively. These ligands were used to synthesis complexes in general molecular formula [MLnCl2], where M= Co(II) and Ni(II) and n=(1-4). The ligands and the complexes were characterized by (1H-NMR, UV-Visible and FTIR) spectroscopy, metal content, elemental analysis C.H.N, magnetic and conductivity measurements. The low conductivity values reveal the non-electrolytic nature for the new complexes. All complexes are hexa co-ordinate with (octahedral geometry). Evaluation biological activity for the compounds screened against Gram(-) bacteria (Escherichalcoli, Pseudoaerogenosa) and Gram(+) bacteria (Staphylococcus aureus, staphylococcus epidermidis) and the optimized structure for the compounds carried out by using DFT calculation..