关键词: 双金属配合物, X-射线衍射, NMR, 稀土, 铝

Abstract: Crystal structures of the titled complexes have been determined by X-ray diffraction technique.Nd-Al and Y-Al complexes are isomorphous and both have two Al and two rare earth ions as coordination metals with a center symmetry.Each Ln is coordinated by 6 TFAG and two THF molecules forming a distorted tricapped triprismatic polyhedron and each Al is coordinated by two i-Bu and two TFAG forming a tetrahedron.It is found that TFAG has three linking types:(A) the two oxygen atoms in one of the three TFAG link with a Nd ion.(B) the two oxygen atoms in the second TFAG separately link with a Nd and an Al atom.(C) one of the two oxygen atoms in another TFAG bidentately coordinated to two Nd ions and another oxygen separately coordinates to Al and one of the two Nd ions.In the case of (C) the carbon atom attached at two oxygen atoms has a SP³ orbital configuration,rather than a SP² type due to hydrogen addition.1D and 2D NMR results demonstrated the existence of such a TFAG disproportionate ligand.It is also found that the coordination structure in solution keeps invariant as it is in the solid state.The NMR spectra indicate the presence of two i-Bu conformations under slow exchange in THF solution.

Key words: Bimetallic complex, X-ray diffraction, NMR, Rare earth, Aluminum