Zirzlmeier Johannes, Schrettl Stephen, Brauer Jan C, Contal Emmanuel, Vannay Laurent, Brémond Éric, Jahnke Eike, Guldi Dirk M, Corminboeuf Clémence, Tykwinski Rik R, Frauenrath Holger
Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058, Erlangen, Germany.
Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Materials, Laboratory of Macromolecular and Organic Materials, EPFL - STI - IMX - LMOM, MXG 037, Station 12, 1015, Lausanne, Switzerland.
Nat Commun. 2020 Sep 23;11(1):4797. doi: 10.1038/s41467-020-18496-4.
The optoelectronic properties of various carbon allotropes and nanomaterials have been well established, while the purely sp-hybridized carbyne remains synthetically inaccessible. Its properties have therefore frequently been extrapolated from those of defined oligomers. Most analyses have, however, focused on the main optical transitions in UV-Vis spectroscopy, neglecting the frequently observed weaker optical bands at significantly lower energies. Here, we report a systematic photophysical analysis as well as computations on two homologous series of oligoynes that allow us to elucidate the nature of these weaker transitions and the intrinsic photophysical properties of oligoynes. Based on these results, we reassess the estimates for both the optical and fundamental gap of carbyne to below 1.6 eV, significantly lower than previously suggested by experimental studies of oligoynes.
各种碳同素异形体和纳米材料的光电特性已得到充分证实，而纯sp杂化的卡宾在合成上仍然难以实现。因此，其性质常常是从特定低聚物的性质推断而来。然而，大多数分析都集中在紫外-可见光谱中的主要光学跃迁上，而忽略了在明显更低能量处经常观察到的较弱光学带。在这里，我们报告了对两个同系低聚炔系列的系统光物理分析和计算，这使我们能够阐明这些较弱跃迁的性质以及低聚炔的固有光物理性质。基于这些结果，我们将卡宾的光学带隙和基本带隙估计值重新评估至低于1.6 eV，明显低于先前低聚炔实验研究所表明的值。
