Transition metal coordination complexes based on V-shaped bis-triazole ligand: syntheses, structures, and properties

Abstract

Hydrothermal reactions of 1,3-bis(1,2,4-triazol-1-yl)benzene (btb) and M(NO₃)₂ (M = Co²⁺ (1), Cu²⁺ (2)) afforded two new coordination polymers, [Co(btb)₂(NO₃)(H₂O)]_n·NO₃·H₂O (1) and [Cu(btb)₂(NO₃)₂]_n (2), respectively. Single-crystal X-ray diffraction reveals that 1 crystallizes in the space group P2₁/m and 2 crystallizes in the space group Pī, both showing a double-stranded chain structure. The 1-D chains are interconnected via π⋯π interactions to lead to 2-D ladder-like supramolecular architectures. In addition, magnetic behavior and thermal stability of 1 and 2 have been investigated. For 1, weak antiferromagnetic interactions are observed at low temperature, and the data obey the Curie–Weiss law χ_M = C/(T−θ), with C = 3.22 cm³·mol⁻¹·K and θ = −10.39 K. For 2, the decrease of the χT vs. T curve at low temperature is the result of intermolecular antiferromagnetic magnetic interactions.

Keywords:

• Crystal structure
• 1,3-Bis(1,2,4-triazol-1-yl)benzene
• transition metal
• thermal stability
• magnetic property