Structural diversity for three Zn(II) coordination polymers from 4-nitrobenzene-1,2-dicarboxylate and bispyridyl ligand

Abstract

Three Zn(II) complexes, [Zn₂(bpp)₂(FNA)₂]·H₂O (1), [Zn(bpp)(FNA)]·H₂O (2), and Zn₂(bpp)₂(FNA)₂ (3) (bpp = 1,3-bi(4-pyridyl)propane, H₂FNA = 4-nitrobenzene-1,2-dicarboxylic acid), were synthesized and characterized by single-crystal and powder X-ray diffraction methods, IR spectroscopy, TG analyses, elemental analyses, and fluorescent analysis. In 1, the Zn(II) ions are linked by FNA anions and bpp into 2-D layers. The Zn(II) ions in 2 are bridged by FNA anions into chiral chains, which are interlinked by bpp into 3-D metal–organic framework with (6⁵·8) CdS topology. Complex 3 features 1-D zigzag chains, which are interconnected by bpp ligands to give a 3-D framework with (6·7⁴·8)(6⁴·7·8) topology. Complexes 2 and 3 exhibit significant ferroelectric behavior (for 2 remnant polarization Pr = 0.050 μC cm⁻², coercive field Ec = 1.13 kV cm⁻¹, saturation of the spontaneous polarization Ps = 0.239 μC cm⁻²; for 3 Pr = 0.192 μC cm⁻², Ec = 4.64 kV cm⁻¹, Ps = 0.298 μC cm⁻²).

Keywords:

• Zn(II)
• coordination polymers
• fluorescence
• ferroelectric
• topology

Acknowledgements

This project was sponsored by K.C. Wong Magna Fund in Ningbo University.

Funding

This work was supported by the Scientific Research Fund of Zhejiang Provincial Education Department.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Scientific Research Fund of Zhejiang Provincial Education Department.