Novel Trumpet-Shaped Conjugation Bridge (Carbon Nanocone) for Nonlinear Optical Materials

Abstract

Trumpet-shaped carbon nanocone (CNC) is used as a π-conjugated bridge to design high-performance nonlinear optical (NLO) material. Owing to the attractive trumpet-shaped structure, O2N–CNC–NH2 exhibits nonlinear optical behavior that is both surprisingly and qualitatively distinct from conventional π-conjugated organic species. It has been shown that the electron-acceptor nitryl (−NO2) at the apex of the trumpet and the electron-donor amino (−NH2) at the bottom edge of the trumpet to form O2N–CNC–NH2 is beneficial to improve the NLO response of CNC. Significantly, the first hyperpolarizabilities (βtot) of O2N–CNC–NH2 show an arc-shaped change as −NH2 substituting different H atoms along the arc-shaped bottom edge of CNC. Interestingly, the βtot values of H–CNC–NH2 also show an arc-shaped change. By comparison of the βtot values of O2N–CNC–NH2 and H–CNC–NH2, it has been found that no matter which bottom H of H–CNC–H is substituted by NH2, the βtot value of H–CNC–NH2 will be increased about 1.6 times after ...