Novel bis-nitrile grafted [6]Helicenes through a photochemical pathway: Chiroptical and photophysical properties
作者:Sondes Raouafi、Basim H. Asghar、Faouzi Aloui
DOI:10.1016/j.molstruc.2020.129087
日期:2021.2
enantiomeric separation of these helical compounds was accomplished by chiral HPLC leading to (P)- and (M)-enantiomers with high optical purity (94.3–100% ee) demonstrating a large opticalrotatorydispersion and significant electronic circulardichroism (ECD) signals. UV–vis absorption and photoluminescence of these helical compounds have been evaluated showing a notable behavior and a strong fluorescence
2,15-Dibutoxy-6,11-dicyano[6]Helicene (CN-HEL) has been prepared through a two-step sequence under mild conditions, in an overall 78% yield, starting from 2,7-bis(cyanomethyl)naphthalene as a suitable material. The Helicene has been experimentally characterized and its absorption and photoluminescence (PL) properties have been evaluated showing a blue emission in the visible spectrum. A strong absorption
2,15-Dibutoxy-6,11-dicyano[6]Helicene ( CN-HEL ) 已在温和条件下通过两步序列制备,总产率为 78%,从 2,7-双(氰基甲基)开始萘作为合适的材料。Helicene 已通过实验表征,其吸收和光致发光 (PL) 特性已被评估,在可见光谱中显示蓝色发射。强吸收完全在紫外区(λ max = 290 nm),而荧光发生在 400 nm。这相当于 1.17 eV (9482 cm -1 ) 的斯托克斯位移,这是针对小分子报道的最大斯托克斯位移之一,使其成为光电应用的有希望的候选者。此外,1H NMR、FT-IR、UV-vis 和 PL 光谱是通过非常有效的时间相关密度泛函理论 (TD-DFT) 方法计算的。具有两个推荐的密度泛函(PBEPBE 和 cam/B3LYP)和扩展基组的计算光谱与相应的实验数据进行了很好的比较。还通过实验研究了 HOMO 和