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 (H 2 O) 4 (1) and {[Zn(5-AN) 2 ] (H 2 O)} 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.