Diacetoneglucose Complexes of Manganese(II) and Iron(II) and Their Organometallic Derivatization

Homoleptic metal-sugar complexes were obtained in the form of MnIIand FeII-diacetoneglucose derivatives. The protolysis of [Mn3Mes6] and [Fe2Mes4] (Mes ) 2,4,6-Me3C6H2) with DAGH (1,2:5,6-di-O-isopropylideneR-D-glucofuranose, diacetoneglucose) led to [M(DAG)2] [M ) Mn (1), Fe (2)]. Although monomeric in solution, they showed a different degree of aggregation in the solid state, iron being monomeric and manganese oligomeric (see magnetic properties). Dimeric complexes from 1 and 2 were obtained in the reaction with 9,10-phenanthroline [phen], leading to [(phen)2M(μ-DAG)2M(DAG)2] [M ) Mn (3), Fe (4)]. The organometallic functionalization of 1 and 2 was achieved Via a ligand redistribution reaction mixing them with [Mn3Mes6] and [Fe2Mes4], respectively. The reaction led to mixed alkoxo aryl trinuclear complexes in the form of [(Mes)2M2(μ-DAG)2M(μ-Mes)2] [M ) Mn (5), Fe (6)]. Both have a linear trimetallic skeleton with Mn‚‚‚Mn and Fe‚‚‚Fe average distances of 2.93 and 2.88 Å, respectively. The crystal data are as follows: complex 5, C60H82Mn3O12, monoclinic, space group P21, a ) 10.289(5) Å, b ) 20.878(5) Å, c ) 14.015(5) Å, â ) 93.19(2)°, Z ) 2; complex 6, C60H82Fe3O12, monoclinic, space group P21, a ) 9.748(12) Å, b ) 26.05(3) Å, c ) 12.50(2) Å, â ) 107.50(2)°, Z ) 2. The data were collected at -123 °C. For 5 and 6 the magnetic analysis showed a strong antiferromagnetic coupling between the M(II) centers, with spin frustration leading to an overall S ) /2 and S ) 2 ground state, respectively.