Lanthanide oxalatophosphonates with two- and three-dimensional structures

Reactions of lanthanide nitrate, oxalate sodium and 2-pyridylmethylphosphonic acid (2-pmpH 2) under hydrothermal conditions result in five new lanthanide oxalatophosphonates with two types of structures. Compounds [ Ln 4(ox) 5(2-pmpH) 2(H 2O) 7]·5H 2O [ Ln 3+=Gd ( 1), Tb ( 2), Dy ( 3); ox 2−=C 2O 4 2−] exhibit a double layer structure, made up of net-like { Ln 4(ox) 5} n layers containing Ln 10(ox) 10 rings which are connected by 2-pmpH ‐. While compounds [ Ln 4(ox) 5(2-pmpH) 2(H 2O) 6]·6H 2O [ Ln 3+=Ho ( 4), Yb ( 5)] display a three-dimensional framework structure in which the { Ln 4(ox) 5} n layers are cross-linked by 2-pmpH. The solid state luminescent and magnetic properties are investigated. Compounds [ Ln 4(ox) 5(2-pmpH) 2(H 2O) 7]·5H 2O ( Ln=Gd, Tb, Dy; 2-pmp=2-pyridylmethylphosphonate) and [ Ln 4(ox) 5(2-pmpH) 2(H 2O) 6]·6H 2O ( Ln=Ho, Yb) with 2D and 3D structures, respectively, are reported.