Design of tri-substituted dodecatungstosilicate from a trilacunary silicotungstate by insertion of manganese ions of [Mn3(μ 3-O)(2-Cl-benzoato)6(py)3]: Synthesis, structure, redox and magnetic studies

摘要

A mixed-valent manganese tricapped Keggin polyoxometalate (3) has been designed by insertion of three Mn atoms from [Mn~(II)Mn ~(III)_2(μ_3-O)(2-Cl-benzoato) _6(py)_3] (1) into the vacant sites of the trilacunary precursor Na_(10)[A-α-SiW_9O_(34)] (2). This compound exhibits strong antiferromagnetic interaction between the spin carriers of the Mn mixed-valent trinuclear moiety, which suggests an S = 5/2 ground state. A Keggin polyoxometalate α-[Mn~(II)Mn~(III)_2(H_2O)_3SiW_9O_(37)]~(8-) (3) has been designed by insertion of three Mn atoms from [Mn ~(II)Mn~(III)_2(μ_3-O)(2-Cl-benzoato) _6(py)_3] (1) into the vacant sites of Na _(10)[A-α-SiW_9O_(34)] (2). Compound 3 exhibits antiferromagnetic interaction between the Mn centres, which leads to an S = 5/2 ground state.