Syntheses and Crystal Structures of Anionic Lanthanide Chloride Complexes [(CH3)2NH2][LnCl4(HMPA)2] (Ln = La, Nd) and [(CH3)2NH2]4[LnCl6]Cl (Ln = Nd, Sm, Eu)
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, P.O. Box 537, SI 1001 Ljubljana, Slovenia.
Reactions of lanthanide oxides, hexamethylphosphoramide (HMPA), chlorotrimethylsilane and water in tetrahydrofuran (THF) afforded new complexes [(CH3)2NH2][LnCl4(HMPA)2] (Ln = La (1), Nd (2)) and [(CH3)2NH2]4[LnCl6]Cl (Ln = Nd (3), Sm (4), Eu (5)). Lanthanide oxides react with in situ formed HCl, while the cations [(CH3)2NH2]+ are formed by the hydrolysis of HMPA with the cleavage of P–N bonds. The X-ray crystal structures of the complexes 1–5 are reported. The complexes 1 and 2 are the first known compounds with HMPA coordinated to a lanthanide in an anion.
Key words: crystal structure, lanthanide chloride complexes, P–N bond cleavage, anionic complexes