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)
Saša Petriček
Faculty of Chemistry and Chemical Technology, University of Ljubljana,
Aškerčeva 5, P.O. Box 537, SI 1001 Ljubljana, Slovenia.
E-mail: sasa.petricek@fkkt.uni-lj.si
Abstract
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