2-Amino-4-methylpyrimidine: A simple supramolecular scaffold for carboxylic acid complexes both in solid and solution states

Studies concentrating on hydrogen bonding interactions between 2-amino-4-methylpyrimidine (AMPY) with selected dicarboxylic acids have been investigated in the solid state. Two pyrimidinium-dicarboxylate organic salts with stoichiometry 1:1 [AMPY: maleic acid] and 2:1 [AMPY:d(+)-malic acid] have been prepared and characterized by X-ray crystallographic analysis. Maleic and d(+)-malic acids were found to exhibit unique supramolecular polymeric structures with AMPY involving proton transfer to the specific ring nitrogen of AMPY. As an extension, AMPY has been used to build a receptor structure 1. Receptor 1 shows binding of dicarboxylic acids in CH3CN and represents a marginal selectivity with d(+)-malic acid. Binding interactions were investigated by UV–vis and fluorescence studies.