Two Cd(ΙΙ) complexes with xanthene-9-carboxylate ligand: syntheses, crystal structures, and emission properties

Abstract

Two new Cd^II complexes, [Cd(L)₂(CH₃OH)₂]_∞ (1) and [Cd(L)₂(pyz)(H₂O)]_∞ (2), have been prepared by the reaction of xanthene-9-carboxylic acid (HL) and Cd(ClO₄)₂·6H₂O in the presence or absence of pyz co-ligand (L = xanthene-9-carboxylate and pyz = pyrazine). Their structures were determined by single-crystal X-ray diffraction. Complex 1 possesses a 1-D zigzag chain structure, whereas 2 has a 1-D linear chain that is further assembled into a 2-D network, and then an overall 3-D framework by inter-chain O–H ··· O hydrogen bonds and C–H ··· π supramolecular interactions. Both 1 and 2 are photoluminescent and their emission properties are closely related to their intrinsic structures.

Keywords:

• Cd^II complexes
• Xanthene-9-carboxylate
• Crystal structures
• Luminescent properties

Acknowledgments

This study was supported by the National Natural Science Fund of China (Grant Nos. 20801049 and 21071129) and Henan Outstanding Youth Science Fund (Grant No. 114100510017).