Preparation of metal- organic frameworks with bimetallic linkers and corresponding properties

A series of metal-organic frameworks (MOFs) with bimetallic linkers were synthesized through a facile reflux route. Several parameters such as the reaction temperature, the ratio of aluminum to iron, and the ratio of terephthalic acid to metal ions affecting the adsorption properties of the resulting MOFs for glutathione were systematically investigated. It was found that the reaction conditions investigated affected the adsorption capacity of the prepared MOF materials for glutathione. For adsorption experiments, the effects of the solution pH, initial concentration and contact time on the adsorption were also investigated. The results showed that a high initial concentration and contact time were favorable for the adsorption process, while the solution pH exhibited little influence on the adsorption. Under optimum reaction conditions, the adsorption capacity increased by 52.53% and 27.81%, compared to the prepared MOF materials with an iron linker and aluminum linker, respectively. Analyses of the infrared spectra, pore sizes of MOFs and molecular size of glutathione indicated that hydrogen bonding, coordination and sieving effects participated in the entire adsorption process. The results showed that the prepared MOF material with bimetal linkers could be regarded as a potential adsorbent to enrich peptides with low molecular weight like glutathione from aqueous solution.