Three new complexes, [ Co(hfac)/sub 2/(NIToPy) ] (1), [ CoCl/sub 2/(NIToPy)/sub 2/ ] (2), and [ Co(NIToPy)/sub 3/] (ClO/sub 4/)/sub 2/ (3), with NIToPy=2-(2-Pyridyl)- 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-oxy-3-oxide, and hfac= hexafluoroacetylacetonate, have been synthesized. The compound 3 crystallized in the monoclinic space group P2/sub 1/, with two molecules in a unit cell of dimensions a=10.565(4).ANG., b=14.714(9).ANG., c=14.596(7).ANG., and.beta.=107.10(4).degree.. The temperature-dependent magnetic susceptibility measurements (4.2K-300K) for the complexes demonstrated strong antiferromagnetic exchange interaction between cobalt(II) ion and NIToPy radical spins with J=-140.1cm/sup -1/ for 1, J=-94.2cm/sup -1/ for 2, and J=-161.8cm/sup -1/ for 3, respectively. The magneto-structural correlation in these complexes has been discussed.
Journal of the Chinese Chemical Society=中國化學會會誌 44(4), pp.439-443