Structural diversity and solid-state properties of Co^II and Zn^II coordination complexes with 5-aminonicotinate through metal direction

Abstract

Zinc and cobalt 5-aminonicotinate (5-AN^–) complexes, Co(5-AN)₂(H₂O)₄ (1) and {[Zn(5-AN)₂](H₂O)}_n (2), have been hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction results indicate that coordination geometries are different (octahedral for Co^II and tetrahedral for Zn^II) and 5-AN⁻ adopts distinct binding modes (terminal in 1 and bridging in 2), forming a simple mononuclear coordination motif for 1 and a 2-D (4,4) coordination layer for 2. The higher-dimensional supramolecular architectures for both complexes are constructed via hydrogen bonding. Both complexes have been characterized by IR, microanalysis, and powder X-ray diffraction techniques and, their thermal stability and fluorescence have also been investigated.

Keywords:

• Metal-directed assembly
• Hydrogen bonding
• 5-Aminonicotinate

Acknowledgement

This work was financially supported by Tianjin Normal University (No. 52XQ1104).