A promising strategy for two-photon absorption materials by novel dicarbazole-conjugated C60/C70 fullerene derivatives

Two novel fullerene dyads C60-CBP (3) and C70-CBP (4) containing an electron donor 4,4′-dicarbazole-1,1′-biphenyl (CBP) unit have been prepared through 1,3-dipolar cycloaddition reactions in situ. Their structures are characterized by 1H NMR, 13C NMR, FTIR, and MALDI-TOF-MS. Spectroscopic and electrochemical properties of 3 and 4 are studied in detailed by UV–vis, fluorescence, and cyclic voltammetric analysis, which present diminutive electronic interactions between the C60/C70 and CBP units, and the half wave potentials of 3 and 4 are more negative than those of C60/C70. The two-photon absorption (TPA) properties are determined for them by Z-scan method. Their geometric were optimized by the DFT calculations on the level at 6–31G (d,p) basis set.