The detections of fullerenes and (possibly) planar C_{24} (a small fragment of a graphene sheet) in the H-rich circumstellar environments of evolved stars show that formation of these complex species does not require an H-poor environment contrary to general expectation. This together with the very recent identification of the fullerene cation C_{60}^{+} as a diffuse interstellar band (DIB) carrier (the only DIB carrier known to date) reinforce the idea that these molecular nanostructures are ubiquitous in space. The understanding of the formation route of these complex organic species requires an interdisciplinary research, crossing the boundaries between astronomers, chemists, and physicists, with potential applications in nanotechnology and industry. Here, I review the main results of the interdisciplinary approach carried out at the Instituto de Astrofísica de Canarias (IAC) in order to learn about complex molecular nanostructures in evolved stars. Finally, I underline the main open questions and future directions like the expected observations on these complex organics in evolved stars from future facilities such as the James Webb Space Telescope.