A one-dimensional compound with a Mn(III)-NC-Fe(III) linkage of the formula of [NEt4]2[Mn(acacen)][Fe- (CN)6] (NEt4 ) tetraethylammonium, acacen ) N,N¢-ethylenebis(acetylacetonylideneaminato)) has been prepared by the assembly reaction of [Mn(acacen)Cl] and [NEt4]3[Fe(CN)6] in ethanol/2-propanol. The compound crystallizes in the orthorhombic space group Pnma with the cell dimensions of a ) 17.415(5) Å, b ) 19.79(1) Å, c ) 11.471(4) Å, and Z ) 4. The compound assumes a one-dimensional snaky-chain structure consisting of (-Mn- NC-Fe-CN-)n repeating units with dimensions of Fe-C ) 1.952(4) Å, Mn-N ) 2.316(4) Å, Mn-N-C ) 152.6(3)°, Fe-C-N ) 177.1(4)°, in which the Fe ion is positioned at the inversion center, the [Mn(acacen)] moiety lies on a mirror plane, and the adjacent one-dimensional chains run like a snake along the b axis with the same phase. On lowering of the temperature, the effective magnetic moment per FeMn increases gradually from 5.05 íB at room temperature and then abruptly below ca. 20 K to 15.5 íB at 1.9 K, indicating that the onedimensional chain is a ferromagnetic chain due to an intrachain ferromagnetic coupling between Mn(III) and Fe(III) ions through the bridging CN- group. The FCM curve (field-cooled magnetization) under 1 Oe showed a spontaneous magnetization below 2.5 K. The magnetization vs H up to 55 kOe at 1.9 K showed an extremely large zero-field susceptibility, indicating that the compound is a ferromagnet due to a weak interchain ferromagnetic coupling.
|Titolo:||Magnetic Properties of a One-Dimensional Ferromagnet Containing a Mn(III)−NC−Fe(III) Linkage: Synthesis and Crystal Structure of a Chainlike [Mn(acacen)Fe(CN)6]n2n-Polyanion|
GALLO, EMMA (Secondo)
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||1996|
|Digital Object Identifier (DOI):||10.1021/ic960556g|
|Appare nelle tipologie:||01 - Articolo su periodico|