Synthesis and structural characterization of the lanthanide Schiff-base complexes {N[CH 2CH 2NCH(2-O-3,5- t-Bu 2C 6H 2)] 3}Ln (Ln=Sm, Nd)

Abstract

Reaction of Ln[N(SiMe 3) 2] 3 (Ln=Sm, Nd) with one equivalent of the bulky heptadentate Schiff-base ligand N[CH 2CH 2NCH(2-OH-3,5- t-Bu 2C 6H 2)] 3 ( 1) resulted in formation of the 7-coordinate complexes {N[CH 2CH 2NCH(2-O-3,5- t-Bu 2C 6H 2)] 3}Ln (Ln=Sm ( 2), Nd ( 3)). X-ray diffraction studies of 2 and 3 reveal isostructural hemi-toluene solvate complexes in which the N 4O 3 donor atom set of the ligand defines a slightly distorted capped octahedral geometry about the metal center. Ln–N bond lengths are of two types — an average of 2.556(3) Å ( 2) (2.587(5) Å ( 3)) to the three imine nitrogens, and a significantly longer interaction of 2.818(4) Å ( 2) (2.811(5) Å ( 3)) with the apical amine nitrogen. Ln–O distances lie in the range 2.218(3)–2.232(4) Å for 2 and 2.241(6)–2.248(4) Å for 3.