摘要
纯有机超长寿命室温磷光(p-RTP)材料因其独特的光物理性质,低成本,结构可设计性及其在生物影像、疾病诊疗、传感与防伪加密等领域的应用前景引起了广泛关注.然而,要实现兼具高效且颜色可调的p-RTP余辉发射,仍颇具挑战.受簇聚诱导发光(CTE)机理启发,选用三聚氰胺(MA)和环酰脲化合物海因(HA)及二氢尿嘧啶(DHU)作为电子给体和受体,采用共晶策略制备了 1∶1计量组成的共晶.较MA、HA及DHU单组分晶体而言,共晶展现出更好的p-RTP颜色可调性及更长寿命,这是共晶中广泛存在C=O、孤对电子、多重氢键、适当电荷转移及多重簇发光中心等协同作用的结果,并进一步展示了这些共晶材料在高端防伪保密领域的应用.
Abstract
Pure organic materials with persistent room-temperature phosphorescent(p-RTP)have attracted extensive attention due to their unique photophysical properties,low cost,design flexibility,and promising applications in such areas as biomedical imaging,disease diagnosis and treatment,sensing,and anti-counterfeiting encryption.Achieving efficient,long-lived,and tunable p-RTP afterglows,however,remains a significant challenge.Herein,inspired by the clustering-triggered emission(CTE)mechanism,utilizing the cocrystallization strategy,cocrystals with stoichiometric ratio of 1∶1 were prepared by employing melamine(MA)and cyclic acylureas of hydantoin(HA)and dihydrouracil(DHU)as electron donor and acceptors,respectively.Compared to the single-component crystals of MA,HA,and DHU,the cocrystals exhibited better color-tunability and longer lifetimes for p-RTP emissions,which are attributable to the synergistic effects of the widespread presence of C=O groups,lone pair electrons,multiple hydrogen bonds,appropriate charge transfer,and multiple emissive clusters.Furthermore,advanced anti-counterfeiting and encryption applications of these cocrystalss were demonstrated.
NETL
NSTL
万方数据