A ureido-pyrimidone based aspartic acid derivative: synthesis and pH-responsive self-assembly in water†
Due to its high association constants, 2-ureido-4[1H]-6-methyl-pyrimidinone (UPy) has been widely used in the fabrication of functional supramolecular assemblies and materials. In this work, a UPy-based aspartic acid derivative, 2-(3-(6-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)hexyl)ureido)succinic acid (UPy-Asp), was synthesized using UPy-based isocyanates and aspartic acid. UPy-Asp exhibited a pH-responsive self-assembling behavior in an aqueous solution due to the aspartic acid moieties. The UPy-Asp aggregates can be repeatedly transformed between nanowires and nanosheets by changing the pH, and can be used as templates for silver nanofibers or silver nanosheets.