Two new helicenes based on carbazole and anthracene units were designed, namely 15-hexyl-15 H-tetrapheno [1,2-b] carbazole (6) and 15-hexyl-12- (thiophen-2-yl)-15 H-tetrapheno [1,2-b] carbazole (11) and successfully synthesized by photocyclization reaction. Their structures were characterized by \(^1\) H NMR, \(^{13}\) C NMR, mass spectrometry, and single-crystal X-ray diffraction analysis. Compounds 6 and 11 had good solubility and relatively high thermal stability with thermal decomposition at 237 and 217 \(^\circ \) C, respectively. They had absorption maximum peaks at 295 nm for 6 and 245 nm for 11, and emitted blue light with the peaks at 469 nm for 6 and 478 nm for 11 in dichloromethane. Especially, the fluorescence quantum yields of compound 6 in different solvents were measured ranging over 3–6% while those of compound 11 are in the range of 27–50%. The introduction of functional substituents like thiophene on the backbone of compound 6 could increase the fluorescence quantum yields by about eight times. In contrast to compound 11, compound 6 exhibited remarkable two-photon absorption performance. It particularly showed stronger absorption at excitation wavelengths ranging from 730 to 870 nm, reaching a maximum \(\delta \) value of 24.1 GM at 730 nm. The synthetic concept would provide a useful approach to enhance specific physicochemical performances in the field of organic optoelectronic materials.
