Zeolitic imidazolate frameworks (ZIFs) are a subgroup of crystalline porous materials
known as metal-organic frameworks (MOFs) in which zeolite-like three-dimensional
structures are formed by coordinating metal ions (typically Zn or Co) with imidazolate
linkers.
To avoid low level yields caused by a decrease in pH resulting from the acid formed
during reaction, zinc oxide is used as the zinc precursor. This ensures that water is the
only by-product of the reaction. Additionally, formic acid is used to achieve a more
efficient proton transfer from the imidazolate linker, which directly affects the kinetics of
the chemical reaction.
In this work, ZIF-93 and ZIF-71 were synthesised. Methanol was used as an
environmentally friendly solvent, along with formic acid with the same side group as
methanol (methyl). The rate of product formation was investigated as a function of the
formic acid concentration in the solvent. Furthermore, the effect of stirring and the effect
of water present among reactants or products in the synthesis of ZIF-71 were evaluated.
Phase analysis was performed using X-ray powder diffraction and the Rietveld
refinement method.
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