Extended systems based on diazinedicarboxylate ligands and voluminous metals

Resum

This work contains the synthesis and the chemical and structural characterisation of eighty nine compounds based on diazinedicarboxylate ligands (pyridazine-3,6-dicarboxylate, pyrimidine-4,6-dicarboxylato and pyrazine-2,5-dicarboxylate) and voluminous metals.Lanthanide metals promote the ligand decomposition that generates oxalate anions to render {Ln2(diazinedicarboxylate)2(oxalate)}n compounds. However, oxalate-free {Ln2(diazinedicarboxylate)3}n compounds are obtained by controlling the reaction conditions. The structural diversity found in both systems can be rationalised according to ion size of the lanthanide and the entropic effect of the synthesis temperature. The solvent-free method affords compounds containing nitrate anions coming from the lanthanide salts. Luminescence and magnetic properties of these compounds have been also accomplished.Moreover, the thermal decomposition of the employed amide solvents generates organic cations that direct the assembly of indium architectures, which range from discrete assemblies to extended frameworks according to the synthetic conditions and the hydrogen bonding capacity of the cations.Finally, the use of cadmium has afforded a porous compound in which the relationship between the crystallinity degree and the adsorptive capacity has been evaluated by means of N2, CO2 and CO capture. The partial replacement of CdII atoms by MnII or ZnII modulates the affinity of this material towards CO2.