Abstract: Nine novel dinuclear complexes of transition metal ions with pentabenzimidazolylmethyl diethylene triamine are reported.The results of variable temperature magnetic susceptibility of the complexes indicated that an antiferromagnetic exchnge interaction exists between metal ions in dinuclear unit.Themagnitude of thespin interaction (J) of the complexes had the following sequence|J_{Cu(Ⅱ).S=1/2}|>|J_Ni(Ⅱ).S=1|>|J_{Co(Ⅱ).S=3/2}|>|J_{Ma(Ⅱ).S=5/2}|. The preliniinflry rexults of bioassay shwed that some complexeshd antitumor activities in vitro, regulating plant growth and fungicidal activities.

Key words: transition metal complex, benzimidazole, magnetic property, bioactivity