Facile synthesis and characterization of trimesic acid-Cu based metal organic frameworks

Graphical abstract: - Highlights: • Various MOFs based on trimesic acid (TMA) and various Cu (II) salts. • Benign preparation of TMA-Cu based MOFs in DI water and ethanol. • TMA-Cu MOFs with the mole ratio of Cu(II) to TMA varying between 1.5 and 2. • TMA-Cu MOF with conductivity values were 8.26E−08–5.29E−11 (S/cm). - Abstract: Metal-organic frameworks based on trimesic acid (TMA) as organic linker and Cu (II) as metal ions from different metal salts such as CuCl₂, Cu(NO₃)₂, CuSO₄ and Cu(CH₃COOH)₂ were prepared in relatively environmentally friendly media e.g., at room temperature in DI water and at the boiling point of ethanol. The prepared TMA-Cu MOFs showed very interesting porosity and optical coloring based on the source of the used metal salts and preparation medium. The prepared MOFs were characterized in terms of their porosity with BET measurements and it was found that about 850 m²/g for the MOF prepared from Cu(NO₃)₂ salt in ethanol. The amounts of metal ions connected to TMA were determined by atomic absorption spectroscopy measurements (AAS) after dissolution of TMA-Cu MOFs by concentrated HCl treatments. From AAS measurements the mole ratio of Cu(II) to TMA was found to vary between 1.5 and 2, depending on the source of metal ions and the solvent used during preparation. The structural analysis and thermal characterization of the prepared MOFs were done by using FT-IR and TGA analysis, respectively. Additionally, TMA-Cu based MOF disks were prepared and their conductivities were determined by I–V measurements. The conductivity of TMA-Cu MOFs was calculated to be between 8.26E−08 and 5.29E−11 S/cm