Synthesis, structural and magnetochemical studies of iron phosphonate cages based on {Fe 3O} 7+ Core

We report the synthesis, structures, and magnetic properties of twelve iron(111) phosphonate cages: [Fe 4(μ 3-O)CI(PhCO 2) 3-(PhPO 3) 3(py) 5] 1, [Fe 4(μ 3-O)( tBuCO 2) 4(C 10H 17PO 3) 3(py) 4] 2 (C 10H 17PO 3H 2 = camphylphosphonic acid), [Fe 7(μ 3-O) 2(PhPO 3) 4(MeCO 2) 9(py) 6] 3, [Fe 7(μ 3-O) 2(PhPO 3) 4(PhCO 2) 9(py) 6] 4, [Fe 7(μ 3-O) 2( tBuPO 3) 4( tBuCO 2) 8(py)8] (NO 3) 5, [Fe 7(μ 3-O) 2(PhPO 3) 4(MeCO 2) 8(py) 8] 6, [Fe 9(μ 3-O) 2(μ 2-OH)(PhPO 3) 6( tBuCO 2) 10(MeCN) (H 2O) 5] 7, [Fe 9(μ 3-O) 2(μ 2-OH)(C 10H 17PO 3) 6(PhCO 2) 10(H 2O) 6] 8, [Fe 6(μ 3-O) 2(O 2)( tBuCO 2) 8(PhPO 3) 2(H 2O) 2] 9, [Fe 6(μ 3-O) 2(O 2)( tBuCO 2) 8(C 10H 17. PO 3) 2(H 2O) 2] 10, [Fe 6(μ 3-O) 2(O 2)( tBuCO 2) 8( tBuPO 3) 2(py) 2] 11, and [Fe 14(μ3-O) 4(O 2) 2(PhPO 3) 8( tBuCO 2) 12(H 2O) 12](NO 3) 212. The results have allowed us to compare the magnetic exchange found with magneto-structural correlations found previously for iron-oxo cages. © 2009 American Chemical Society.