Nowadays molecular and supramolecular chemistry have endless examples for the development of smart devices. Among those applications, Nano-baskets of calixarenes play vital roles in host-guest chemistry. One of the main appealing concepts of this field is the development of host molecules with gate features. These are constructed for delivery of chemical or biochemical species that are volatile, or reactive, or sensitive to normal solution environment and they are mainly functioned by predefined stimuli such as concentration, temperature, pH and so on. In our previous study, we found that bromine functionalized benzyl groups can be used to extend the phenol group of p-tert-butylcalix[4]arene. In this study 5-bromomethyl-1,3-benzenediacetic acid will facilitate the formation of two ligating arms for p-tert-butylcalix[4]arene. The ligating arms are expected to act as a gate responding upon pH changes. Scheme below shows the expected reaction of the ligating arm with the calix[4]arene. A precursor of the ligating arm has been synthesized through multi steps process. Synthetic intermediates and the target molecules are characterized by 1H and 13C NMR and Mass spectroscopy analysis. The synthetic target molecule will be used as a host molecule, and benzaldehyde and its derivatives will be investigated as potential guest molecules to mimic fragrance or volatile compounds (Scheme below). Gating features will be investigated by braking and reforming of the hydrogen bonds under the influence of pH changes.

Synthesis toward a molecular container based on p-tert-butylcalix[4]arene with gating features

255th National Meeting (2018)

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