Scheme 1. Luminescent ionic mesogenic molecules with different anions and decorated by two or three alkyl tails.

Light and cognate phenomena, e. g., luminescence are powerful tools endowed with great sensitivity to explore the infinitely small. Molecular salts, especially those based on imidazolium units, are granted with original properties and structural versatility. Associated with fluorophores, they constitute highly bioavailable platforms. Their interactions with negatively charged species and biological membranes as well as their controllable cytotoxicity imparted their applications as anion receptors, but also a promising potential as antibacterial and anticancer agents whose mechanism of action can be observed using luminescence, opening the possibility of theranostics (therapy and diagnosis). One of the other assets of imidazolium salts is their flexible amphipathic character which promotes their self‐organizations into liquid‐crystal mesophases and their ability to mimic lipids. Combining luminescence to these amphipathic properties opens new prospects, e. g., following gene or drug delivery inside cells. These salts, all‐in‐one, should lead to new tools for biologists, as well as active theranostic molecules.

The Cover Feature shows a luminescent ionic naphtalene molecular structure. By playing with the nature of the anion and the amphipathic character, it is possible to promote luminescence properties in the three states of matter (solid, liquid crystal, and liquid) as well as to control the supramolecular mesomorphic architecture in layers (black triangle with positive smectic units) or columns (background with a typical hexagonal columnar texture). More information can be found in the Full Paper by L. Douce et al.