Polynuclear coordination precursor compounds for M3Fe5O12 garnets (M = Y, Eu, Gd and Er).

A new type of complexes compounds (NH4)6[M3Fe5(C4O5H4)6(C4O5H3)6]·16H2O (where M(III) = Y, Eu, Gd, Er), (NH4)6[M3Fe5(C4O6H4)6(C4O6H3)6]·16H2O (where M(III) = Gd, Er) and (NH4)6[M3Fe5(C6O7H10)6(C6O7H9)6]·xH2O (where M(III) = Y; x = 8; M(III) = Eu, Er; x = 22) [C4O5H42– = malate anion; C4O6H42– = tartarate anion, C6O7H11– = gluconate anion] have been synthesized and characterised by elemental chemical analysis and physico-chemical measurements (IR, UV-Vis spectroscopy and magnetic determinations). The synthetic possibilities offered by the use of these new compounds as potential precursors for garnets have been suggested.