New lanthanide(III) disiloxanediolates: Syntheses and structures

Three new chloro-functionalized lanthanide(III) bis(disiloxanediolate) complexes, [{(Ph2SiO)2O}2{Li(DME)}2]Nd(DME)Cl (3), [{(Ph2SiO)2O}2{Li(THF)2}2]HoCl·2THF (4), and [{(Ph2SiO)2O}2{Li(THF)2}2]ErCl·2THF (5) have been prepared by the treatment of anhydrous lanthanide trichlorides, LnCl3 (Ln = Nd, Ho, Er), with two equivalents of in situ prepared (Ph2SiOLi)2O (2). In a similar manner, the treatment of PrCl3 with 2 equivalents of (Ph2SiOLi)2O (2) in the presence of LiN(SiMe3)2 afforded the silylamide-functionalized derivative [{(Ph2SiO)2O}2{Li(THF)2}2]Pr[N(SiMe3)2] (6). All new compounds have been structurally characterized by X-ray diffraction analyses. Compounds 4 and 5 represent a new intermediate structural type of lanthanide bis(disiloxanediolates) between the “inorganic metallocenes” (Pr, Nd, Sm) and the “metallacrowns” (Sc, Y).