RESUMEN
A series of zinc aryloxides, [Zn4(sal-Me)8]â 2.5(C7H8) (1), [Zn4(sal-Me)8]â CH2Cl2 (2), [Zn4(µ3-OR)2(sal-R)6] (3) (for R=Me (0.51), Et (0.49)), [Zn4(µ3-OMe)4(sal-Me)4(HOMe)4] (4), [Zn(sal-Me)2(py)2]â THF (5), {[Zn(sal-Me)2(tmbpy)] â 2(C6H5CH3)}n (6), [Zn2(sal-Me)2(THF)2Cl2] â 0.5(C6H5CH3) (7), and [Zn4(µ3-OMe)2(sal-Me)4Cl2] (8) (Hsal-Me=methyl salicylate, py=pyridine, tmbpy=4,4'-trimethylenedipyridine) were obtained that have different nuclearities and central core topologies and contain ligands of different basicity and coordination abilities.
RESUMEN
In this study, a new method for the synthesis of heterometallic 3d-4f alkoxides by the direct reaction of metallic lanthanides (La, Pr, Nd, Gd) with MCl2 (M = Mn, Ni, Co) in 2-methoxyethanol was developed. The method was applied to the synthesis of the heterometallic oxo-alkoxide clusters [Ln4Mn2(µ6-O)(µ3-OR)8(HOR)xCl6] (Ln = La (1), Nd (2), Gd (3); x = 0, 2, 4); [Pr4M2(µ6-O)(µ3-OR)8(HOR)xCl6] (M = Co (4), Ni (5); x = 2, 4); and [Ln4Mn2(µ3-OH)2(µ3-OR)4(µ-OR)4(µ-Cl)2(HOR)4Cl6] (Ln = La (11) and Pr (12)). Mechanistic investigation led to the isolation of the homo- and heterometallic intermediates [Pr(µ-OR)(µ-Cl)(HOR)Cl]n (6), [Co4(µ3-OR)4(HOR)4Cl4] (7), [Ni4(µ3-OR)4(HOEt)4Cl4] (8), [Mn4(µ3-OR)4(HOR)2(HOEt)2Cl4] (9), and [Nd(HOR)4Cl][CoCl4] (10). In the presence of an external M(II) source at 1100 °C, 1-4 and 12 were selectively converted into binary metal oxide nanomaterials with trigonal or orthorhombic perovskite structures, i.e., LaMnO3, GdMnO3, NdMnO3, Pr0.9MnO3, and PrCoO3. Compound 5 decomposed into a mixture of homo- and heterometallic oxides. The method presented provides a valuable platform for the preparation of advanced heterometallic oxide materials with promising magnetic, luminescence, and/or catalytic applications.