A series of lanthanide glutarates: lanthanide contraction effect on crystal frameworks of lanthanide glutarates

Abstract

A series of lanthanide glutarates [Ln(phen)(glu)Cl]_n {Ln = Y (1a), Tm (1b); phen = 1,10-phenanthroline; glu = glutarate}, [Ln₂(phen)₂(glu)₃]_n {Ln = Ce (2a), Tb (2b), Ho (2c)} and [La₂(glu)₃(H₂O)₃]_n·5nH₂O (3) have been hydrothermally synthesized and characterized structurally. Compounds 1a–b are isostructural and consist of 1-D neutral [Ln(phen)(glu)Cl]_n chains, which are built up from the linkages of [Ln(phen)Cl]³⁺ ions and glutarate ligands. Compounds 2a–c are isostructural and contain 2-D [Ln₂(phen)₂(glu)₃]_n layers, where Ln³⁺ ions are connected by three kinds of glutarate ligands. The 3-D framework of compound 3 is constructed by the linkages of La³⁺ ions and glutarate ligands. Although some 3-D lanthanide glutarates have been reported, they exhibit a very robust structural type, whose structure is not changed by different Ln³⁺ ions, but compound 3 shows a new structural type. A systematic investigation of six lanthanide glutarates and some reported compounds revealed that the well-known lanthanide contraction has a significant influence on the formation of lanthanide glutarates. The photoluminescent properties of 1b and 2b, and magnetic properties of 1b, 2b and 2c have been studied.