New copper(II), manganese(II), cobalt(II), nickel(II) and palladium(II) complexes, [Cu(L)(X)(H2O)] [X= OAc- (1), Cl- (3), ClO4- (4)], [M(L)2(H2O)2] [M= Cu2+(2), Mn2+(5)], [M(L)(OAc)(H2O)] [M= Co2+(6), Pd2+(8)], [Ni(L)(OAc)] (7) were synthesized with 2-(5H-dibenzo [a,d][7] annulen-5-ylacetyl)-N-(4-chlorophenyl) hydrazinecarbothioamide (HL). All the metal complexes have been characterized by different physico-chemical techniques like molar conductivity, magnetic susceptibility measurements, electronic and infrared spectral studies, elemental and thermal analysis. The toxicity of newly synthesized compounds was evaluated using the Daphnia magna bioassay.