Inorganic Chemistry, Vol.45, No.16, 6135-6137, 2006
Characterization of the chloranilate(center dot 3-) pi radical as a strong spin-coupling bridging ligand
Dinuclear [( TPA) Co-II( CA(2-)) Co-II( TPA)]( BF4)(2)center dot 2MeOH ( 1) [ TPA = tris-( 2-pyridylmethyl) amine] and [( TPA) Co-II( CA(center dot 3-)) Co-II( TPA)]( BF4)center dot 2Et(2)O ( 2) with a bridging chloranilate radical ligand formed by reduction of 1 are crystallographically and magnetically characterized. 1 has shown a weak antiferromagnetic coupling within the CoII dimer [ J/k(B) = -0.65 K ( -0.45 cm(-1))], while 2 has a 2 orders of magnitude stronger antiferromagnetic interaction between the CoII ion and a radical [ J/k(B) = -75 K ( 52 cm(-1))].