Syntheses, structures, and luminescence of three metal carboxylate polymers of 2,5-dibenzoylterephthalic acid and N-donor auxiliary ligands

Abstract

Three coordination polymers, [CdL(2,2′-bpy)] (1), [ZnL(phen)₂] (2), and [ZnL(2,2′-bpy)] (3) (H₂L = 2,5-dibenzoylterephthalic acid, 2,2′-bpy = 2,2′-bipyridine, and phen = 1,10-phenanthroline), were synthesized and crystallographically characterized. The compounds were further characterized by elemental analyses, FTIR, thermogravimetric analyses, and powder X-ray diffraction. Complex 1 exhibits a 2D sheet structure with (4,4) grid units, while 2 and 3 present infinite 1D zig–zag chain structures. The complexes are all extended into high-dimensional supramolecular networks through intermolecular hydrogen bonds and π–π stacking interactions. A structural comparison of 1–3 demonstrates that the characteristics of subsidiary ligands and slight difference in coordination models of L play a very important role in construction of the complexes. Additionally, luminescence of the complexes is also investigated at room temperature.

Keywords:

• Coordination polymer
• 2,5-Dibenzoylterephthalic acid
• 2,2′-bpy
• Phen
• Luminescence

Acknowledgments

We gratefully acknowledge financial support by the NSF of China (21071027, 20771023), the China High-Tech Development 863 Program (2007AA03Z218) and analysis & testing foundation of Northeast Normal University, and Research Fund for the Doctoral Program of Hebei United University (2012).