Enantiopure distorted ribbon-shaped nanographene combining two-photon absorption- based upconversion and circularly polarized luminescence†




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.

在本文中,我们描述了扭曲的带状纳米石墨烯,其在石墨烯相关材料中展现出前所未有的光学性质组合,即基于双光子吸收的上转换(TPA-UC)以及圆偏振发光(CPL)。 该化合物是约的石墨烯分子。 2nm长度和1nm宽度具有边缘缺陷,其促进平面晶格的变形。 边缘缺陷是芳香族马鞍形酮单元和[5]碳硼烷部分。 该系统显示出双光子吸收和圆偏振发光以及21.5ns的非常长的发射寿命。 [5]螺旋烯负责手性活动,而推拉几何和sp2碳的扩展网络是有利于非线性吸收的因素。 电子结构理论计算支持结果的解释。




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