Construction of Cu(ii) coordination polymers based on semi-rigid tetrahedral pyridine ligands

Abstract

The assembly of a Cu(II) ion and the semi-rigid tetrahedral pyridine ligand, tetrakis(3-pyridyloxymethylene)methane (L¹), yields three coordination polymers (1–3) by synergy between different solvent mixtures. Single crystal X-ray diffraction analyses reveal that Cu₄(L¹)(OAc)₈ (1) features a two-dimensional sql network, and comprises dimeric five-coordinated Cu-centered square pyramids as the inorganic building units; Cu₂(L¹)(C₇H₅O₂)₄ (2) is also a layered assembly but with a 3,4-connected 3,4L13 net. In this complex, mononuclear CuO₂N₂ square planar structures and dinuclear CuO₃N₂ square pyramids both serve as the inorganic building units. Cu(H₂O)₂(L¹)(OAc)₂ (3) is a three-dimensional framework structure based on six-coordinated CuO₂N₄ square bipyramidal inorganic nodes and tetrahedral semi-rigid pyridine ligands, and dia topology is simplified for 3.