Dichlorido(crown ether)lanthanoid(III) tetrachloroaluminate complexes

Reactions between LnCl 3 , AlCl 3 and a crown ether (18-crown-6 and dibenzo18-crown-6) in MeCN have led to the isolation of four new lanthanoid halide crown ether complexes, [PrCl(μ-Cl)(18-crown-6)] 2 [AlCl 4 ] 2 ·2MeCN ( 1 ), [YbCl 2 (18-crown-6)][AlCl 4 ]·MeCN ( 2 ), and [LnCl(μ-Cl)(dibenzo18-crown-6)} 2 ][AlCl 4 ] 2 ·6.5MeCN (Ln = La, 3 , Pr, 4 ). 1 was also obtained by unexpected halide transfer on addition of 18-crown-6 (18C6) to MeCN solutions of [Pr(MeCN) 9 ][AlCl 4 ] 3 . Complexes 1 , 3 and 4 have dinuclear chloride-bridged nine-coordinate cations, and 2 has an eight coordinate mononuclear cation.