Mononuclear Iron(III) and Manganese(III) Complexes with Substituted Salicylaldimine Ligands: Structure, Magnetic Properties, and Catalytic Activity of Olefins‐Epoxidation

Two mononuclear manganese(III) and iron(III) complexes with substituted salicylaldimine ligands, [MnL(H 2 O) 2 ]Cl·H 2 O ( 1 ) and [FeL(H 2 O)(Cl)]CH 3 CN ( 2 ) [H 2 L = 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 α‐methylstyrene by NaOCl. With 1 the epoxides were produced in 75% yield with cis:trans = 12:88 from cis ‐stilbene and 82% from α‐methylstyrene, and with 2 the epoxides were produced in 43% with cis:trans = 30:70 from cis ‐stilbene and 71% from α‐methylstyrene.