Design and construction of Zn(II) coordination polymers made by pincer type pyridine-hydrazine based ligands

Abstract

A new series of five zinc (II) coordination polymers, namely [Zn(LI)(NO3)(OH2)]n (1), [Zn(LI)(CH3COO)]n (2), [Zn(LI)(NCS)]n (3), [Zn(LII)(CH3COO)]n (4), and {[Zn2(LII)2(N3)2] ⋅H2O}n (5), has been self-assembled from different zinc (II) salts and pyridine-hydrazine ligands {HLI = 2-pyridinecarbaldehyde isonicotinoyl hydrazone, and HLII = 2-acetyl-pyridyl-isonicotinoylhydrazone} and has been structurally characterized. In all compounds, the ligand is singly-deprotonated and coordinates to the zinc center in the enolic form (=N–N=C–O-). In other words, the pyridine-hydrazine ligand acted as a tetradentate negatively charged chelating-bridging ligand and coordinated to the metal centers in N, N,..