Zn(ii) and Cd(ii) coordination polymers assembled by di(1H-imidazol-1-yl)methane and carboxylic acid ligands

Abstract

Five new Zn^II/Cd^II coordination polymers constructed from di(1H-imidazol-1-yl)methane (L) mixed with different auxiliary carboxylic acid ligands formulated as [Zn(L)(H₂L¹111)₂·(H₂O)_0.2]_n (1), {[Zn(L)(L²22)]·H₂O}_n (2), {[Cd₂(L)₂(L²22)₂]·2H₂O}_n (3), {[Cd(L)(L³3)]·H₂O}_n (4) and [Cd(L)(L⁴4)]_n (5) (H₃L¹111 = 1,3,5-benzenetricarboxylic acid, H₂L²22 = 4,4′-oxybis(benzoic acid), H₂L³3 = m-phthalic acid and H₂L⁴4 = p-phthalic acid) have been synthesized under hydrothermal conditions and structurally characterized. Four related auxiliary carboxylic acids were chosen to examine the influences on the construction of these coordination frameworks with distinct dimensionality and connectivity. The coordination arrays of 1–5 vary from 1D zigzag chain for 1, 2D (4,4) layer for 2–4, to 2-fold interpenetrated 3D coordination network with the α-Po topology for 5. The thermal and photoluminescence properties of complexes 1–5 in the solid state have also been investigated.