New Coordination Polymers of Zinc(II), Copper(II) and Cadmium(II) with 1,3-Bis(1,2,4-triazol-4-yl)adamantane

• Main Authors: Nertil Xhaferaj, Aurel Tăbăcaru, Marco Moroni, Ganna A. Senchyk, Kostiantyn V. Domasevitch, Claudio Pettinari, Simona Galli
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Inorganics
• Subjects: coordination polymers; poly(azolate) spacers; 1,3-bis(1,2,4-triazol-4-yl)adamantane; zinc; copper; cadmium
• Online Access: https://www.mdpi.com/2304-6740/8/11/60

The new coordination polymers (CPs) [Zn(tr₂ad)Cl₂]<i>_n</i>, {[Cu(tr₂ad)Cl]Cl∙4H₂O}<i>_n</i>, [Cd₂(tr₂ad)Cl₄]<i>_n</i>, {[Cu(tr₂ad)(NO₃)](NO₃)}<i>_n</i> and {[Cd(tr₂ad)(NO₃)](NO₃)∙H₂O}<i>_n</i> were obtained in the form of air- and moisture-stable microcrystalline powders by the solvothermal reactions of zinc(II), copper(II) and cadmium(II) chlorides or nitrates with the ligand 1,3-bis(1,2,4-triazol-4-yl)adamantane (tr₂ad). Investigation of the thermal behaviour assessed the thermal stability of these CPs, with [Cd₂(tr₂ad)Cl₄]<i>_n</i> starting to decompose only around 365 °C. As retrieved by powder X-ray diffraction, while [Zn(tr₂ad)Cl₂]<i>_n</i> features 1-D chains along which the metal centre shows a tetrahedral geometry and the spacer is exo-bidentate, the other CPs contain 2-D double-layers in which the metal ions possess an octahedral stereochemistry and the linker is exo-tetradentate. A comparative structural analysis involving known coordination compounds containing the tr₂ad ligand enabled us to disclose (i) the versatility of the ligand, as far as the coordination modes are concerned; (ii) the variability in crystal structure dimensionality, ranging from 1-D to 3-D; (iii) the fact that, to the best of our knowledge, [Zn(tr₂ad)Cl₂]<i>_n</i> is the first Zn^II-based CP containing the tr₂ad spacer.