Two synthetic routes were employed for the preparation of iron(III) haloalkoxides in the presence of titanium(IV). Three crystalline products (A, B and C) were isolated and characterised by chemical and physical techniques including X-ray diffractometry, Mössbauer and EPR spectroscopies and variable-temperature magnetic susceptibility measurements. Products B and C are common to both synthetic routes. Product A is a mononuclear iron(II) complex, trans-[FeCl2(HOPri)4], probably produced by the oxidation of propan-2-ol by FeCl3 in the reaction medium. B is the ionic, mixed-metal [Ti3(μ3-OPri)2(μ-OPri)3(OPri)6][FeCl4], while C is a high-yield oxo-haloalkoxide, [Fe5(μ5-O)(μ-OPri)8Cl5]. Magnetic moment measurements in [2H8]-tetrahydrofuran solution from 323 to 173 K indicate that C contains antiferromagnetically coupled iron(III) centres with intermediate (S = 3/2) spin configuration. C is polymorphic in the solid state, crystallising in the monoclinic or the tetragonal systems as non- and mono-solvate species, respectively. The highly (Lewis) acidic character of iron(III), together with its oxophilic character, probably determined the formation of B and C instead of the targeted mixed-metal [FeIIICl(2 − x){Ti2(OPri)(9 + x)}], x = 0 or 1. The possibility of formation of heteronuclear alkoxides containing both iron(III) and titanium(IV) is re-assessed in the light of the results obtained in this work.
You have access to this article
Please wait while we load your content...
Something went wrong. Try again?