COSJWST is an ambitious multidisciplinary project to study complex organic species (e.g., fullerene and graphene species and their derivatives, among others) in the imminent James Webb Space Telescope (JWST) era. COSJWST will enable us to take a fundamental step forward in improving our understanding of the complexity of organic matter in space (formation/destruction chemical pathways, relationship between the different species, detection of new complex carbon molecular nanostructures, etc.). The detection of the most common fullerenes (C60 and C70) and (possibly) planar C24 (a small fragment of a graphene sheet) in Planetary Nebulae (PNe) and diverse astrophysical environments raises the exciting possibility that other more complex fullerene- and graphene-based molecules (e.g., metallofullerenes, carbon onions or multishell fullerenes, fullerene-adducts) might be ubiquitous in the Universe and continue to be serious candidates to explain many astrophysical phenomena; this idea is reinforced by the recent identification of the fullerene cation C60+ as a diffuse interstellar band (DIB) carrier (the only DIB carrier known to date).

COSJWST goes beyond the state-of-the-art to understand complex organic species in space by combining unprecedented astronomical data (e.g., using the upcoming JWST infrared data but also from other top-level astronomical facilities at different wavelengths), novel organic chemistry synthesis, and powerful quantum-chemistry calculations.

The complex compounds to be explored by COSJWST are similar to the organic species found in proto-planetary disks and Solar System (SS) bodies, among other space environments, and their study may have important implications in other research areas. COSJWST will cross the boundaries between astronomers, chemists, and physicists, with future potential applications in nanotechnology and industry.