“…In this manner, the optical activity of diradical croconate and squarate dyes has been extensively studied during the last decades due to the intense color and the narrow and strong band they present in the red to near‐infrared (NIR) region of the absorption spectra, so that they have become very popular in the photovoltaic field . For instance, in the design of dye‐sensitized solar cells with enhanced light harvesting capabilities in the NIR ,,. Such interest has motivated the detailed theoretical and experimental characterization of their singlet‐singlet transitions,,,, and it is well known that the presence of donor or acceptor moieties on the backbone, π‐conjugation,,,, or heavy atoms may lead to modifications in the absorption energy.…”