Hydrothermal synthesis, structure, and properties of lead(II)-based coordination compounds with R-isophthalic acid (R=OH, CH₃)

Abstract

Three new lead(II)-based coordination polymers, [Pb(5-OH-BDC)] _n  · nH₂O (1) (5-OH-BDC = 5-hydroxyisophthalate), [Pb₂(5-CH₃-BDC)₂] _n (2), and [Pb₂(5-CH₃-BDC)₂(phen)₂] _n  · 2nH₂O (3) (5-CH₃-BDC = 5-methylisophthalate, phen = 1,10-phenanthroline), have been hydrothermally synthesized, structurally determined by single-crystal X-ray diffraction, and characterized by elemental analyses, IR spectra, and thermogravimetric analyses. Both 1 and 2 exhibit 2-D double-layer network structures, while 3 possesses 1-D chain structure bridged by 5-CH₃-BDC. The coordination sphere of Pb(II) in 1 is holodirected, whereas in 2 and 3 the spheres feature hemidirected structures. Fluorescence properties of 1–3 have been investigated in the crystalline state at room temperature.

Keywords:

• Pb(II)-based coordination compound
• Isophthalate
• Hydrothermal synthesis
• Structural analysis
• Fluorescence spectrum

Acknowledgments

We gratefully acknowledge the financial support from the National Natural Science Foundation of China (Grant No. 20873100 and 21173168) and the Nature Science Foundation of Shaanxi Province (Grant Nos. FF10091 and SJ08B09).