Catecholase activity of a structurally characterized dinuclear iron(III) complex [Fe~(III) _2(L)_2] [H_3L = N,N′-bis(3-methoxysalicylaldimine)-1,3-diaminopropan-2-ol]

摘要

A dinuclear Fe(III) complex, [Fe~(III) _2(L)_2] (1) [H_3L = N,N′-bis(3-methoxysalicylaldimine)-1,3- diaminopropan-2-ol], has been synthesized and characterized using microanalysis, spectroscopy and X-ray crystallography. Structural analysis reveals a pentadentate chelation behaviour of the trianionic ligand H_3L, having a distorted octahedral coordination environment around each iron(III) center with an FeN_2O_4 chromophore. Variable-temperature magnetic susceptibility measurements of 1 indicate an antiferromagnetic interaction between the two iron(III) centers, coupled with J = -28.5. 1 behaves as an effective catalyst towards the oxidation of 3,5-di-tert-butylcatechol in different solvents, viz. methanol, dichloromethane and acetonitrile, to its corresponding quinone derivative in aerial oxygen. The reaction follows Michaelis-Menten enzymatic reaction kinetics with turnover numbers (K _(cat)) 7.51 × 10~2, 1.69 × 10~3 and 1.23 × 10~3 h~(-1) in methanol, dichloromethane and acetonitrile, respectively.