State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science, Fudan University , Shanghai 200433, P. R. China.
ACS Appl Mater Interfaces. 2016 Mar;8(12):7938-47. doi: 10.1021/acsami.6b00832. Epub 2016 Mar 18.
Series of graphene molecules with varied emission colors have been prepared by oxidative cyclodehydrogenation using anhydrous ferric chloride (FeCl3) as the catalyst under mild conditions. By controlling the oxidation time in the initial step only, molecules with different fluorescence colors are conveniently obtained. New colors can be recorded evidently because of the stepwise and controllable process, which highly related to the conjugation length. Blue emissive starting compounds in the solid state can be transformed into orange upon brief oxidation, whereas green emissive oligomers are varied to red with an emission wavelength redshift about 123 nm. Cyclic voltammetry measurements performed can give the corresponding data, which verify the results drawn from the UV and PL spectroscope. The gradual change of conjugation length with tunable emission is confirmed in the MALDI-TOF study as well. Further characterizations indicate that the graphene molecules possess satisfactory optical properties, which are highly emissive both in solution and in the solid state because of the alkyl group. In addition, the good thermal stability and the self-assembly of graphene molecules suggest that they are promising candidates for high-tech applications. Furthermore, the fabricated field-effect transistors possess the nice performance, whose mobilities are about 0.57 cm(2) V(-1) s(-1) with an on-off ratio of 1 × 10(4) and 0.81 cm(2) V(-1) s(-1) with an on-off ratio of 1 × 10(3), respectively.
通过在温和条件下使用无水三氯化铁 (FeCl3) 作为催化剂进行氧化环脱氢反应，已经制备了一系列具有不同发射颜色的石墨烯分子。通过仅控制初始步骤中的氧化时间，可以方便地获得具有不同荧光颜色的分子。由于该过程是逐步的和可控的，因此可以明显记录到新的颜色，这与共轭长度密切相关。在固态下具有蓝色发射的起始化合物在短暂氧化后可以转变为橙色，而绿色发射的低聚物则通过发射波长红移约 123nm 转变为红色。进行的循环伏安测量可以给出相应的数据，这验证了从紫外和 PL 光谱仪得出的结果。MALDI-TOF 研究也证实了共轭长度随可调发射的逐渐变化。进一步的表征表明，由于烷基的存在，石墨烯分子具有令人满意的光学性能，在溶液和固态中都具有很高的发光性。此外，良好的热稳定性和石墨烯分子的自组装表明它们是高科技应用的有前途的候选者。此外，所制造的场效应晶体管具有良好的性能，其迁移率分别约为 0.57cm2V-1s-1（开关比为 1×10(4)）和 0.81cm2V-1s-1（开关比为 1×10(3)）。
