An analysis of known synthetic methods for dibenzoylmethanide (dbm-) complexes of lanthanides of different nuclearity, viz. [Ln(dbm)3(H2O)], [Ln4(dbm)10(OH)2], [Ln5(dbm)10(OH)5] and [KLn(dbm)4]n (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) has been carried out. These methods have been optimized, the range of lanthanides for the compounds extended, and novel complex species, viz. [KLn(Me2CO)(dbm)4]2 (Ln = Eu, Dy, Yb) and [Nd3(dbm)8(OH)(H2O)], have been produced. The nature of the lanthanides in some cases affects the composition of the products formed. The compound [KEu(Me2CO)(dbm)4]2 in solution can transform to [KEu(dbm)3(OBz)]n, containing benzoate (OBz-). For the seven new complexes, the crystal structures have been determined by X-ray diffraction. Photoluminescent properties of the europium complexes have been studied. Their composition and structure influence the emission band shape and quantum yields. Two solid solutions of heterolanthanide complexes [ErxYb5-x(dbm)10(OH)5] (x = 1.2, 2.0) have been prepared, as shown by high-resolution powder XRD analysis.
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