Three Cd(II) coordination polymers based on a pyridyldicarboxylate: effect of coordinated water

Abstract

By systematic change of the solvothermal synthesis, three new coordination polymers, [Cd(L)∙(H₂O)]∙2H₂O (1), [Cd(L)∙(H₂O)]∙H₂O (2), and [Cd(L)] (3), have been synthesized based on a tritopic ligand 4-(pyridin-3-yl)isophthalic acid (H₂L). Compounds 1 and 2 show very similar two-dimensional (2D) bilayers further linked by interlayer hydrogen bonds into three-dimensional (3D) supramolecular structures, while 3 displays a 3D structure constructed form one-dimensional (1D) Cd-carboxyl chains. Notably, 1 and 2 have a pair of unusual isomers with the opposite orientation of coordinated H₂O on the metal centers, leading to different hydrogen bonding interactions. Thermal stabilities and solid-state photoluminescences for 1 – 3 were also investigated.

Keywords:

• Coordination polymer
• unsymmetrical ligand
• coordinated water
• fluorescence properties

Supplemental data

The supplemental data for this article can be accessed at https://doi.org/10.1080/00958972.2018.1485899

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgement

We gratefully acknowledge financial support from the National Natural Science Foundation of China (No. 201601145 and 21301062), the NSF of Shaanxi Province (2017JQ2026), and the Ph.D. Start-up Fund of Northwest A&F University (No. 2452015359).