Syntheses, crystal structures and luminescence of 2,6-bis- (5-phenyl-1H-pyrazol-3-yl)pyridine and its d¹⁰ metal complexes

Abstract

A new bis-pyrazole derivative, 2,6-bis-(5-phenyl-1H-pyrazol-3-yl) pyridine (H₂BPPP), and two d¹⁰ metal complexes [Zn(H₂BPPP)Cl₂](DMF)₂ (1), [Cd(H₂BPPP)Cl₂](DMF)₂ (2) have been synthesized and characterized. There is a tautomeric equilibrium of the bis-pyrazole compound in solution and the H atom of pyrazolyl NH can transfer to the adjacent N atoms. X-ray structure analyses reveal the H atom is on the 2-position of pyrazolyl ring in donor solvents, while the H atom is on the 1-position of pyrazolyl ring in metal complexes. The luminescence of the ligand and complexes have been investigated.

Keywords:

• Bis-pyrazole ligand
• Crystal structures
• Proton transfer
• Luminescence

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 20573083) and the Natural Science Foundation of the Educational Bureau of Shaanxi Province (Grant No. 07JK385).