Functionalized Trifluoromethyl-Containing Lithium β-Diketonate in the Synthesis of Homo- and Heteronuclear Complexes of Rare-Earth Metals

Abstract

The reactions of functionalized lithium CF3-β-diketonate (LiL) with trivalent rare-earth metal salts in methanol afford homobinuclear and heterobi(tri)nuclear complexes depending on the nature of the transition metal and anion (chlorides, nitrates, and acetates). In the cases of lanthanum(III) and cerium(III), homoleptic complexes [(LnL3)2] are isolated (CIF files CCDC nos. 2031097 (Ia) and 2031102 (Ib)). The reaction of LiL with praseodymium(III) nitrate gives the new trimetallic structure [(LiPrL3)(LiL)(NO3)(H2O)2] (CIF file CCDC no. 2031103 (II)), and the replacement of nitrate by chloride gives [(PrL3)(LiL)(H2O)] (CIF file CCDC no. 2031104 (IIIa)). Regardless of the nature of the anion of the salt in the series from neodymium(III) to ytterbium(III) and yttrium(III), Ln–Li β-diketonates [(LnL3)(LiL)(solv)] (solv is H2O and MeOH) are formed, and their structures are characterized by X-ray structure analysis (CIF files CCDC nos. 2031099 (IIIb), 2031100 (IIIc), 2031098 (IVa), 2031096 (IVc), 2031094 (IVf), 2031101 (IVg), and 2031095 (IVh)). The equilibrium of the diketonate isomeric forms in a solution of deuterated dimethyl sulfoxide is studied by 19F NMR spectroscopy, and the qualitative composition of the polynuclear complexes is determined by mass spectrometry.