Enantiopure distorted ribbon-shaped nanographene combining two-photon absorptionbased upconversion and circularly polarized luminescence Moreno Cruz, Carlos Márquez, Irene R. Mariz, Inés F. A. Blanco Izquierdo, Víctor Sánchez-Sánchez, Carlos Sobrado, Jesús M. Martín-Gago, José A. Cuerva, Juan M. Maçôas, Ermelinda González Campaña, Araceli Herein we describe a distorted ribbon-shaped nanographene exhibiting unprecedented combination of optical properties in graphene-related materials, namely upconversion based on two-photon absorption (TPA-UC) together with circularly polarized luminescence (CPL). The compound is a graphene molecule of ca. 2 nm length and 1 nm width with edge defects that promote the distortion of the otherwise planar lattice. The edge defects are an aromatic saddle-shaped ketone unit and a [5]carbohelicene moiety. This system is shown to combine two-photon absorption and circularly polarized luminescence and a remarkably long emission lifetime of 21.5 ns. The [5]helicene is responsible for the chiroptical activity while the push–pull geometry and the extended network of sp2 carbons are factors favoring the nonlinear absorption. Electronic structure theoretical calculations support the interpretation of the results. 2019-04-03T12:47:35Z 2019-04-03T12:47:35Z 2018-03-14 info:eu-repo/semantics/article Enantiopure distorted ribbon-shaped nanographene combining two-photon absorptionbased upconversion and circularly polarized luminescence. Chem. Sci., 2018, 9, 3917–3924. [DOI: 10.1039/c8sc00427g]. 2041-6539 http://hdl.handle.net/10481/55335 10.1039/c8sc00427g eng http://creativecommons.org/licenses/by-nc/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial 3.0 España Chemical science