Strong Ferromagnetic Exchange Coupling Mediated By A Bridging Tetrazine Radical In A Dinuclear Nickel Complex

The radical bridged compound [(Ni-(TPMA))(2)-mu-bmte(center dot-)] (BF4)(3)center dot 3CH(3)CN (bmtz = 3,6-bis(2'-pyrimidyl)-1,2,4,5-tetrazine, TPMA = tris(2-pyridylmethyl)amine) exhibits strong ferromagnetic exchange between the S = 1 Ni-II centers and the bridging S = 1/2 bmtz radical with J = 96 +/- 5 cm(-1) (-2J(Ni-rad)S(Ni)S(rad)). DFT calculations support the existence of strong ferromagnetic exchange.