Four Novel Zn (II) Coordination Polymers Based on 4'-Ferrocenyl-3,2':6',3''-Terpyridine: Engineering a Switch from 1D Helical Polymer Chain to 2D Network by Coordination Anion Modulation.

Xuchun Wang,Shengli Li,Yupeng Tian,Lufei Xiao,Wei Du,Jun Zhang,Dajun Wu,Hongping Zhou,Jieying Wu

doi:10.3390/ma10121360

Abstract

Four novel ZnII coordination polymers, [(ZnCl2)2(L)2]n (1), [(ZnBr2)2(L)2]n (2), and [(ZnI2)2(L)2]n (3) and {[Zn(SCN)2]1.5(L)3}n (4), have been synthesized based on 4′-ferrocenyl-3,2′:6′,3′′-terpyridine with ZnII ions and different coordination anions under similar ambient conditions. Their structures have been confirmed using single crystal X-ray diffraction analysis, showing that complexes 1–3 are one-dimensional (1D) double-stranded metal ion helical polymer chains and complex 4 is of a two-dimensional (2D) network. The structural transformations of them from a 1D polymer chain to a 2D network under the influence of the coordination anions has been systematic investigated. Furthermore, the optical band gaps have been measured by optical diffuse reflectance spectroscopy, revealing that the ligand and the complexes should have semiconductor properties.

Highlights

Terpyridines, which are oligopyridines, represent a very popular and versatile building block of ligands for the constructing functional complexes [1]
The two type terpyridine ligands can coordinate with metal ions in the outer pyridine rings, while the central pyridine rings are usually not involved in coordination [2,11]
Ferrocenecarboxaldehyde was synthesized according to a reported method [20]

Summary

Introduction

Terpyridines, which are oligopyridines, represent a very popular and versatile building block of ligands for the constructing functional complexes [1]. Terpyridines possess 48 isomers, of which the. In the three types of terpyridine, 2,20 :60 ,200 -terpyridine possesses bis-chelating ability due to inter-ring C–C bond rotation (in Figure 1a) and has been functionalized. Since 2,20 :60 ,200 terpyridine was first isolated by Morgan and Burstall in the 1930s, it has become a famous building block of functional ligands [3,7,8]. The two type terpyridine ligands can coordinate with metal ions in the outer pyridine rings, while the central pyridine rings are usually not involved in coordination [2,11]

Methods

Results

Conclusion