研究目的
To report a new family of giant star-shaped N-doped nanographenes with diameters up to 6.5 nm and characterize their structural, optoelectronic, and electrochemical properties.
研究成果
The synthesis of highly soluble SNGs with diameters up to 6.5 nm was achieved, allowing full characterization. The radial extension of the π-system resulted in changes in electronic absorption, molar absorptivity, photoluminescence, and electrochemistry, while other properties remained almost invariable. The high molar absorptivity, low LUMO energies, and φΣμ values illustrate the n-type semiconducting character and potential in charge transport and energy conversion applications.
研究不足
The synthesis of extended SNGs is challenging due to the insolubility of planar π systems that tend to aggregate strongly by π-stacking in solution. The high molecular weight of SNG-G2 was at the detection limit of MALDI-TOF HRMS, and single crystals suitable for X-ray diffraction could not be obtained.
1：Experimental Design and Method Selection:
The synthesis involved the careful design of a C3-symmetrical precursor (SNG-G0) from which the SNG core was extended radially. The cyclocondensation of precursor A with cyclohexane-1,2,3,4,5,6-hexaone (HKT) was attempted but led to a linear C2 ribbon-like structure instead of the desired C3 adduct. A new strategy was then employed using a C3 symmetrical precursor with diones far apart and close to tert-butyl solubilizing groups.
2：Sample Selection and Data Sources:
The samples were synthesized from pyrene diketone D and 1,2,3,4,5,6-hexaaminobenzene (HAB).
3：List of Experimental Equipment and Materials:
The synthesis required CHCl3, AcOH, TFA, water, and MnO2 for oxidation. Characterization was performed using 1H-NMR, 13C-NMR, MALDI-TOF HRMS, UV-vis, photoluminescence, cyclic voltammetry, and TRMC.
4：Experimental Procedures and Operational Workflow:
The synthesis proceeded through cyclocondensation, deprotection, and further cyclocondensation steps to yield SNG-G0, SNG-G1, and SNG-G2. The products were purified chromatographically and characterized.
5：The products were purified chromatographically and characterized.
Data Analysis Methods:
5. Data Analysis Methods: The electronic structure was analyzed using TD-DFT and frontier orbital energies computed with the 6-31g(d) basis set and the B3LYP Hamiltonian.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
