Synthesis, characterisation and application of new Cu-based Metal-Organic Frameworks (MOFs)

This work originates from a previous project of the research group I worked with. In said project, a new propargylcarbamate-functionalised isophthalate organic ligand was synthesised and used for the preparation of a new Cu-based Metal-Organic Framework (MOF), named [Cu(1,3-YBDC)]ˑxH2O. Due to the ability of the proprgylcarbmate group to capture Au(III) ions in solution and to reduce them to Au(0), this new MOF was intended to be used as a support for gold nanoparticles, to be used in applications such as electrocatalysis and nitrite sensing. Unfortunately, due to the low porosity and surface area of the material, the capture of Au(III) with [Cu(1,3-YBDC)]ˑxH2O occurs only in small extent, and the electro-assisted reduction occurs only partially, resulting in the presence of all the oxidation states of Au (0, I and III) on the external surface of the material. This work shows the synthesis and characterisation of a new organic ligand, named H2YL80, which maintains the propargylcarbamate functionality of the previous one but also possesses a larger aromatic moiety, envisaging the possibility to obtain a corresponding Cu-based MOF with higher porosity and surface area. The reaction of the new ligand with Cu(NO3)2⸱2.5H2O to obtain a new Cu-based MOF was studied under different conditions, in attempt to synthesise the new material in a crystalline shape which allows the characterisation through X-ray spectroscopy measurements. Despite the numerous attempts, the best results obtained consist in polycrystalline materials. In parallel to those activities, the reactivity of [Cu(1,3-YBDC)]ˑxH2O towards HAuCl4 was studied, to see if the propargylcarbamate functionalities could reduce Au(III) to Au(0) without the aid of electrochemical devices. Finally, the alternative application of [Cu(1,3-YBDC)]ˑxH2O as an adsorbent material for organic dyes was studied by testing the adsorption capacity of the material for Methylene Blue in different conditions.