Due to its amphoteric nature the imidazole ring can function as selective and effective anion and/or cation and even neutral organic molecules receptor system. As a result, the design of new multichannel imidazole-based receptors capable of recognizing different types of analytes is strongly demanded. This review summarizes the most recent and relevant advances in this area.

A self-assembled monolayer of a tetrathiafulvalene derivative on indium tin oxide is shown to operate as a ternary redox switch in which the magnetic and optical outputs are employed to provide a readout of the state. This surface-confined molecular switch exhibits excellent reversibility and stability and is thus promising for the development of molecular electronics.

Despite presenting bioavailability problems, tea catechins have emerged as promising chemopreventive agents because of their observed efficacy in various animal models. To improve the stability and cellular absorption of tea polyphenols, we developed a new catechin-derived compound, 3- O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), which has shown significant antiproliferative activity against several cancer cell lines, especially melanoma. The presence of methoxy groups in its ester-bound gallyl moiety drastically decreased its antioxidant and prooxidant properties without affecting its cell-antiproliferative effects, and the data indicated that the 3-gallyl moiety was essential for its biological activity. As regards its action mechanism, we demonstrated that TMECG binds efficiently to human dihydrofolate reductase and down-regulates folate cycle gene expression in melanoma cells. Disruption of the folate cycle by TMECG is a plausible explanation for its observed biological effects and suggests that, like other antifolate compounds, TMECG could be of clinical value in cancer therapy.

A novel conformationally modulated Intramolecular Electron Transfer (IET) phenomenon has been observed due to the cyclic structure of the diaza[2.2]ferrocenophane 3. The corresponding mixed-valence compound of 3, prepared by electrochemical or chemical partial oxidation, interestingly shows the appearance of two absorption bands in the near infrared (NIR) spectral region. These bands are attributable to two intervalence charge-transfer transitions associated to two atropoisomers exhibiting different energy for the IET process. A solvent and temperature control over the atropoisomeric equilibrium have also been observed. The experimental data and conclusions about both the conformational and the electronic properties of compound 3 are also supported by density functional theory calculations.