Synthesis, structure, and thermal stability of new one-dimensional rubidium coordination supramolecular compound

Abstract

New one-dimensional rubidium dipicolinate hydrate, Rb(Hpdc)(H2pdc)·2H2O, Rb-pdc (H2pdc = pyridine-2,6-dicarboxylic acid) has been grown via hydrothermal method. Single crystal X‐ray diffraction indicates that Rb-pdc reveal a zigzag chain structure, and is composed of RbO7N2 polyhedra, 2,6-pdc ligand, and H2O. Rb-pdc crystallizes in the triclinic space group P1¯ (No.2) with unit cell of a = 6.9050(4) Å, b = 10.9237(7) Å, c = 11.3319(7) Å, α = 94.014(2)°, β = 90.591(2) , γ = 99.6870(10)°, V = 840.28(9) Å3, Z = 2. The observed Rb–O and Rb–N bond distances are 2.904(4)–3.545(4) Å and 3.112(3)–3.159(4) Å, respectively. H-bonds incorporate the chains in Rb-pdc into a 2D (along [1,0,0] direction) network topology. Thermogravimetric analysis (TGA) and powder X-ray diffraction measured at different temperatures show that Rb-pdc exhibits three steps of weight losses, and Rb2O as the final thermal decomposition product is demonstrated. Also, elemental analysis (EA) and infrared (IR) spectrum are performed to identify the chemical composition and characterized bonding.