Blasi Davide, Nikolaidou Domna M, Terenziani Francesca, Ratera Imma, Veciana Jaume
Institut de Ciència de Materials de Barcelona (CSIC)/CIBER-BBN, Campus de la UAB, E-08193 Bellaterra, Barcelona, Spain.
Chemistry Department, University of Parma & INSTM-UdR Parma, I-43124 Parma, Italy.
Phys Chem Chem Phys. 2017 Mar 29;19(13):9313-9319. doi: 10.1039/c7cp00623c.
In this work, the luminescence properties of new materials based on open-shell molecular systems are studied. In particular, we prepared polymeric films and organic nanoparticles (ONPs) doped with triphenylmethyl radical molecules. ONPs exhibit a uniform size distribution, spherical morphology and high colloidal stability. The emission spectrum of low-doped ONP suspensions and low-doped films is very similar to the emission spectrum of TTM in solution, while the luminescence lifetime and the luminescence quantum yield (LQY) are highly increased. Increasing the radical doping leads to a progressive decrease of the LQY and the appearance of a new broad excimeric band at longer wavelengths, both for ONPs and films. Thus, not only the luminescence properties were improved, but also the formation of excimers from stable and persistent supramolecular radical-pairs was observed for the first time. The good stability and luminescence properties with emission in the red-NIR region (650-800 nm), together with the open-shell nature of the emitter, make these free-radical excimer-forming materials promising candidates for optoelectronic and bioimaging applications.
在这项工作中，研究了基于开壳分子体系的新型材料的发光特性。具体而言，我们制备了掺杂三苯甲基自由基分子的聚合物薄膜和有机纳米颗粒（ONP）。ONP呈现出均匀的尺寸分布、球形形态和高胶体稳定性。低掺杂ONP悬浮液和低掺杂薄膜的发射光谱与溶液中TTM的发射光谱非常相似，而发光寿命和发光量子产率（LQY）则显著提高。对于ONP和薄膜，增加自由基掺杂会导致LQY逐渐降低，并在更长波长处出现一个新的宽准分子带。因此，不仅发光特性得到了改善，而且首次观察到由稳定且持久的超分子自由基对形成准分子。这些自由基准分子形成材料具有良好的稳定性和在红-近红外区域（650-800 nm）发射的发光特性，以及发射体的开壳性质，使其成为光电子和生物成像应用的有前途的候选材料。
