Two ligand-length-tunable interpenetrating coordination networks with stable Zn2 unit as three-connected uninode and supramolecular topologies

Abstract

Insight into the control of interpenetrating coordination networks has been strategized by using linear dicarboxylates with different lengths. In this work, we rely on two roles of triethanolamine (H-bonding donations and cooperative stabilization of Zn₂ unit) to target the syntheses of two unique interpenetrating coordination polymers. The two representative compounds, [Zn₄(teaH₂)₂(bdc)₃]·2(MeOH) (1; bdc²⁻ = 1,4-benzenedicarboxylate and teaH₂⁻ = triethanolamine anion) and [Zn₂(teaH₂)(bpdc)_1.5] (2; bpdc²⁻ = biphenyl-4,4′-dicarboxylate), contain a well-defined Zn₂ unit as three-connected uninode but are assembled into two different topology nets. Compound 1 represents the first example of a two-fold interpenetrating 2D → 3D 4·6⁵-crb supramolecular architecture constructed from a two-fold interpenetrating 4·8²-fes subnet, whereas compound 2 shows an unreported self-catenated 3D → 3D 6¹⁵ supramolecular network that can be made by H-bond cross-linking of an eight-fold 10³-ths subnet. The photoluminescent properties of the two compounds have also been investigated.