Department of Chemistry and Namur Research College (NARC), University of Namur (UNamur), Rue de Bruxelles 61, Namur, 5000, Belgium.
Chemistry. 2013 Jun 10;19(24):7771-9. doi: 10.1002/chem.201204598. Epub 2013 Apr 24.
We have prepared a new borazine derivative that bears mesityl substituents at the boron centers and displays exceptional chemical stability. Detailed crystallographic and solid-state fluorescence characterizations revealed the existence of several polymorphs, each of which showed different emission profiles. In particular, a bathochromic shift is observed when going from the lower- to the higher-density crystal. Computational investigations of the conformational dynamics of borazine 1 in both the gas phase and in the solid state using molecular dynamics (MD) simulations showed that the conformation of the peripheral aryl groups significantly varies when going from an isolated molecule (in which the rings are able to flip over the 90° barrier at RT) to the crystals (in which the rotation is locked by packing effects), thus generating specific nonsymmetric intermolecular interactions in the different polymorphs. To investigate the optoelectronic properties of these materials by fabrication and characterization of light-emitting diodes (LEDs) and light-emitting electrochemical cells (LECs), borazine 1 was incorporated as the active material in the emissive layer. The current and radiance versus voltage characteristics, as well as the electroluminescence spectra reported here for the first time are encouraging prospects for the engineering of future borazine-based devices.
我们制备了一种新的硼氮烷衍生物，其硼中心带有均三甲苯取代基，具有出色的化学稳定性。详细的晶体学和固态荧光特性表明存在几种多晶型物，每种多晶型物都显示出不同的发射谱。特别是，从低密度晶体到高密度晶体时观察到红移。使用分子动力学 (MD) 模拟对硼氮烷 1 在气相和固态中的构象动力学进行的计算研究表明，当从孤立分子（其中环能够在室温下翻转 90°障碍）到晶体（其中旋转被包装效应锁定）时，外围芳基基团的构象会发生显著变化，从而在不同的多晶型物中产生特定的非对称分子间相互作用。为了通过制造和表征发光二极管 (LED) 和发光电化学电池 (LEC) 来研究这些材料的光电性能，将硼氮烷 1 掺入发光层作为活性材料。这里首次报道了电流和辐射与电压特性以及电致发光光谱，为未来基于硼氮烷的器件的工程设计提供了令人鼓舞的前景。
