Unusual (4,6)-connected lanthanide 1,3-phenylenediacetate coordination frameworks displaying lanthanide contraction effect and 1D and 2D mixed self-weaving architecture

A series of 2D Ln-organic coordination frameworks (Ln = Sm3+ for 1, Eu3+ for 2, Tb3+ for 3, and Ho3+ for 4) with (4,6)-connected (44.52)(44.5.6)(44.54.66.7) topology has been constructed, in which 1D zigzag chains and 2D (4,4) networks intertwine mutually into the unusual 1D and 2D mixed self-weaving patterns. Interestingly, due to the lanthanide contraction effect, the 9-coordinated geometries of the Ln(III) ions gradually transform from triangle tetrakaidecahedron (Sm3+ and Eu3+), to a three-capped triangle prism (Eu3+ and Tb3+), and then to a single-capped anti-square prism (Ho3+).

Graphical AbstractsFour Ln-organic coordination frameworks (Ln = Sm3+, Eu3+, Tb3+, and Ho3+) with (4,6)-connected (44.52)(44.5.6)(44.54.66.7) topology are described, in which 1D zigzag chains and 2D (4,4) networks intertwine mutually into an unusual 1D and 2D mixed self-weaving motif. Lanthanide contraction effect is also observed to regulate the coordinated geometries of Ln(III) and the overall 3D lattices.Figure optionsDownload as PowerPoint slideResearch Highlights
► In this manuscript, we report a series of 2D Ln-organic coordination frameworks (Ln = Sm3+ for 1, Eu3+ for 2, Tb3+ for 3, and Ho3+ for 4) with (4,6)-connected (44.52)(44.5.6)(44.54.66.7) topology, in which 1D zigzag chains and 2D (4,4) networks intertwine mutually into the unusual 1D&2D mixed self-weaving patterns.
► Interestingly, due to the lanthanide contraction effect, the 9-coordinated geometries of the Ln(III) ions gradually transform from triangle tetrakaidecahedron (Sm3+ and Eu3+), to three-capped triangle prism (Eu3+ and Tb3+), and then to single-capped anti-square prism (Ho3+).
► In this point, the 1,3-pda ligand shows an excellent potential in the formation of new Ln3+ coordination frameworks. Also, the 1D&2D mixed self-weaving architectures observed herein provide new perspectives in Ln-carboxylate coordination chemistry. Additionally, thermal stability and fluorescence of these new materials have also been studied.
► These results will enrich the current research of the flexible ligand on constructing Ln-coordination polymers and provide new insights into its application in designing such crystalline materials with desired structures and properties.