Synthesis, structure and properties of a 3D plywood-like nickel(II) hexaazamacrocyclic coordination polymer constructed from weak Ni⋯O interactions and hydrogen bonding

A 3D plywood-like nickel(II) hexaazamacrocyclic coordination polymer {[Ni(hto)(H2btec]}n (2) (hto = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.16,9]octadecane, H4btec = 1,2,4,5-benzenetetracarboxylic acid) was synthesized by a slow diffusion method and characterized by X-ray crystallography and spectroscopic methods. The structure of 2 is made up of [Ni(hto)]2+ cation and H2btec2− anion in a molecular ratio of 1:1. The nickel(II) ions in the complex are bridged by the H2btec2− ligand based on weak Ni⋯O coordination interactions to form a 1D chain. The alternate cross-like 1D chains are packed in a plywood-like structure and interconnected with each other by hydrogen bonding to form a 3D network. Complex 2 exhibits fluorescent emission in the solid state at room temperature.