DIACETONEGLUCOSE COMPLEXES OF MANGANESE(II) AND IRON(II) AND THEIR ORGANOMETALLIC DERIVATIZATION

Homoleptic metal-sugar complexes were obtained in the form of Mn-II- a nd Fe-II-diacetoneglucose derivatives. The protolysis of [Mn(3)Mes(6)] and [Fe(2)Mes(4)] (Mes = 2,4,6-Me3C6H2) with DAGH 1,2:5,6-di-O-isopro pylidene-alpha-D-glucofuranose, diacetoneglucose) led to [M(DAG)(2)] [ M = Mn (1). Fe (2)]. Although monomeric in solution, they showed a dif ferent 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 [p hen], leading to [(phen)(2)M(mu-DAG)(2)M(DAG)(2)] [M = Mn (3), Fe (4)] . The organometallic functionalization of I and 2 was achieved via a l igand redistribution reaction mixing them with [Mn(3)Mes(6)] and [Fe(2 )Mes(4)], respectively. The reaction led to mixed alkoxo aryl trinucle ar complexes in the form of [(Mes)(2)M-2(mu-DAG)(2)M-(mu-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 Angstrom, respecti vely. The crystal data are as follows: complex 5. C60H82Mn3O12, monocl inic, space group P2(1), a = 10.289(5) Angstrom, b = 20.878(5) Angstro m, c = 14.015(5) Angstrom, beta = 93.19(2)degrees, Z = 2: complex 6, C 60H82Fe3O12, monoclinic, space group P2(1). a = 9.748(12) Angstrom, b = 26.05(3) Angstrom, c = 12.50(2) Angstrom, beta = 107.50(2)degrees, Z = 2. The data were collected at -123 degrees C. For 5 and 6 the magne tic analysis showed a strong antiferromagnetic coupling between the M( II) centers, with spin frustration leading to an overall S = 5/2 and S = 2 ground state, respectively.