Syntheses, structures and thermal stability of three heterobimetallic Cu^IILn^III (Ln = Tb, Tm and Y) coordination polymers bridged by formate

Abstract

Using formate, three heterobimetallic Cu^IILn^III coordination polymers (CPs), [(Cu(Cl)(valen)Ln(NO₃)(CH₃OH)(μ-HCOO)]_n [H₂valen = 1,2-ethanediylbis(2-iminomethylene-6-methoxy-phenol); Ln = Tb(1), Tm(2), Y(3)], were synthesized and characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction analyses. In these complexes, Cu ions are five-coordinate with an elongated square pyramidal (C_4v) geometry, while the Ln (Tb, Tm and Y) ions are nine-coordinate with a muffin (C_s) geometry. In 1-3, the formate bridging ligands adopt a syn-anti coordination mode and cross-link the [(Cu(Cl)(valen)Ln(NO₃)(CH₃OH)]⁺ units into infinite zigzag chains, which are further connected by C-H···O and the C-H···Cl interactions to form 3 D supramolecular structures. In addition, the thermal stabilities of 1-3 were studied. This article offers a promising method for the design of 3d-4f molecular architectures with formate.

Graphical Abstract

Keywords:

• Coordination polymers
• heterobimetallic
• crystal structure
• formate
• thermal stability

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We thank the Natural Science Foundation of Shandong Province (ZR2016BB07) for financial support.