A Cu(II)-MOF based on a propargyl carbamate-functionalized isophthalate ligand - Abstract MYCS

A copper-based metal-organic frameworks (Cu(II)-MOF) functionalized with a new linker, a 5-substituted isophthalic acid bearing a propargyl carbamate group was prepared, intended to provide a support for gold species for potential electrochemical applications. The novel material was fully characterized using several complementary techniques. Synchrotron X-ray diffraction data analysis, in particular, revealed that this MOF, labelled Cu-YBDC contains a complex network of 5-substituted isophthalate anions bound to Cu(II) centers, arranged in pairs within paddlewheel fragments, with a short Cu…Cu distance. Quite unexpectedly, the apical atom in the paddlewheel structure belongs to the carbamate carbonyl oxygen atom. Such extra coordination by the propargyl carbamate groups influences the MOF porosity, a feature that was also confirmed by BET measurements. The particular morphologic conformation of Cu-YBDC is also imaged by means of SEM. Moreover, the surface electrochemical properties of this novel functionalized material are investigated as sensor for nitrite by CV techniques. The new Cu-YBDC MOF, it is immobilized on a glassy carbon electrode by drop-casting (GC/Cu-YBDC). Afterward, GC/Cu-YBDC was treated with HAuCl4 and the direct electro-deposition of Au nanoparticles was obtained (GC/Au/Cu-YBDC). The performance of both electrodes towards nitrite oxidation was tested and it was found that GC/Au/Cu-YBDC exhibited the best electrocatalytic behavior.