Two mononuclear manganese(III) and iron(III) complexes with substituted salicylaldimine ligands, [MnL(H2O)2]Cl·H2O (1) and [FeL(H2O)(Cl)]CH3CN (2) [H2L = N,N￠-(1,1-cyclohexane)bis(3-methoxysalicylaldimine)] were prepared and characterized. The X-ray crystal structure shows that 1 and 2 centers are six-coordinate with distorted octahedral geometry. In 1, the hydrogen bonding of water molecules form a quasi one-dimensional chain structure. The temperature dependence of magnetic susceptibility measurements for complexes of 1 and 2 was analyzed in terms of the zero-field splitting (D) spin-Hamiltonian formula with D = 2.0 cm-1 for 1 and J = 7.5 cm-1, and D = 0.01 cm-1 for 2, respectively. The complexes of 1 and 2 activate the epoxidation of cis-stilbene or a-methylstyrene by NaOCl. With 1 the epoxides were produced in 75% yield with cis:trans = 12:88 from cis-stilbene and 82% from a-methylstyrene, and with 2 the epoxides were produced in 43% with cis:trans = 30:70 from cis-stilbene and 71% from a-methylstyrene.
Relation:
Journal of the Chinese Chemical Society=中國化學會會誌 50(1), pp.41-46
