Synthesis, Structure and Characterization Of Polynuclear Rare Earth Alkoxide Clusters

Abstract

The versatile polyol/polyamine supporting ligand TDCI (1,3,5-tris(dimethylamino)- 1,3,5-trideoxy-cis-inositol was synthesized, and several lanthanide complex clusters of this ligand were produced.The coordination chemistry and characterization of these triangular lanthanide alkoxide clusters was explored. Molecular products include Ln?(H??TDCI)?(L) (Ln = Y, Eu, Gd, Tb, Dy, Ho, Er; L =MeOH, H?O, dipivaloylmethanide, acetylacetonate, dibenzoylmethanide, tetraacetylethane, hexafluoroacetylacetonate).The dysprosium and gadolinium analogues of these clusters were used as secondary building units and were incorporated as preformed entities into coordination polymers linked by squarate (C?O?)?? and benzenedicarboxylate. The dysprosium clusters Dy?(H??TDCI)?(MeOH)? and Dy?(H??TDCI)?(dpm)? (dpm = dipivaloylmethanide) as well as the coordation polymer Dy?(H??TDCI)?(C?O?)?/? were shown to exhibit slow relaxation of magnetization characteristic of single-molecule magnet behavior. The europium and terbium analogues were characterized by spectrofluorimetry. Hexanuclear oxo-centered Dy and Gd clusters were synthesized: the OH-face capped Gd?(??-O)(??-OH)?(??-O)?(PhB(OEt)?)?(dpm)?(HOEt)? and Gd?(??-O)(??-OH)?(dpm)? as well as the edg-bridged [Dy?(??-O)(??-OCH?CF?)??(OCH?CF?)?][Na(thf)?]?. All compounds were characterized by single-crystal X-Ray diffraction.