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

Nertil Xhaferaj,Claudio Pettinari,Kostiantyn V Domasevitch,Simona Galli,Ganna A Senchyk,Aurel Tăbăcaru,Marco Moroni

doi:10.3390/inorganics8110060

Abstract

The new coordination polymers (CPs) [Zn(tr2ad)Cl2]n, {[Cu(tr2ad)Cl]Cl∙4H2O}n, [Cd2(tr2ad)Cl4]n, {[Cu(tr2ad)(NO3)](NO3)}n and {[Cd(tr2ad)(NO3)](NO3)∙H2O}n 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]n starting to decompose only around 365 °C. As retrieved by powder X-ray diffraction, while [Zn(tr2ad)Cl2]n 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]n is the first ZnII-based CP containing the tr2ad spacer.

Highlights

Since the discovery that metal ions and organic ligands can act as connectors and spacers, respectively, to generate infinite frameworks [1], the chemistry of coordination polymers (CPs) [2,3,4,5], including the subclass of metal–organic frameworks (MOFs) [6,7,8,9,10], has recorded a rapid growth, due to the plethora of functional properties they were found to possess
CPs has properties through a modification of the metal ion and/or the organic spacer. In view of their potential generally relied on organic ligands from the class of poly(carboxylic) acids [21,22,23], pyrazines and applications, CPs and
Aiming enlarging and diversifying the library of tr2 ad-based coordination frameworks, we report hereafter on the synthesis, thermal behavior and structural characterization of the five new Synthesis[Zn(tr and Preliminary

Summary

Introduction

Since the discovery that metal ions and organic ligands can act as connectors and spacers, respectively, to generate infinite frameworks [1], the chemistry of coordination polymers (CPs) [2,3,4,5], including the subclass of metal–organic frameworks (MOFs) [6,7,8,9,10], has recorded a rapid growth, due to the plethora of functional properties they were found to possess. One of the main advantages of CPs and MOFs is the possibility to modulate their chemical composition, crystal structure and functional properties through a modification of the metal ion and/or the organic spacer. View of their potential applications, CPs and MOFs appear as interesting platforms which InorganicsIn. 8, 60 may offer sustainable solutions in fields of major economical, technological and environmental importance, e.g., gas storage and separation [11], catalysis [12], luminescence [13,14], conductivity and MOFs is the [16], possibility to [17,18,19]. In view of their potential generally relied on organic ligands from the class of poly(carboxylic) acids [21,22,23], pyrazines and applications, CPs and MOFs appear interesting platforms which may offer sustainable solutions bipyridines [21,22,23,24], phosphonic acidsas [25] and poly(azoles) [26,27,28].

Methods

Results

Conclusion