Twelve new polycyclic aromatic chromophores whose structures recall 9,10-substituted anthracene have been prepared and their absorption spectra, and luminescence properties (both in ethanol and dichloromethane solution at room temperature and in MeOH/EtOH (4:1 v/v) rigid matrix at 77 K) have been analyzed as well as pump-probe transient absorption spectroscopy and computational studies have been performed. The compounds have variously decorated pyrimidyl groups as substituents of the anthracene framework. The compounds are conveniently grouped in two series: 1–4 and 11, in which the pyrimidine nitrogen atoms are on the external side with respect to the anthracene framework (Ext-type compounds), and 5–10, where the pyrimidine nitrogen atoms are pointing towards the anthracene platform (Int-type compounds). Compound 12 contains both a pyrimidine substituent with “inner” nitrogen atoms (“Int”) and a pyrimidine with “outer” nitrogen atoms (“Ext”). All the new species are quite efficient luminophores (spectral range of emission maxima: 400–450 nm at 77 K; 415–520 nm at room temperature; emission lifetimes: 0.25–8.7 ns range; emission quantum yields ranging between 0.08 to 0.99, with a single exception), with their photophysical properties depending on the connection scheme of the pyrimidyl groups to the anthryl platform (i.e., Int-type vs Ext-type compounds). Luminescence originating from locally excited π−π* anthracene-based singlet states, delocalized states largely involving the pyrimidyl moieties, and charge transfer states has been identified. For the Int-type series, the initially-prepared excited state can deactivate via interconversion to a saddle-shaped conformation, opening the way to fast nonradiative decays.

制备了十二种新型多环芳香族发色团，其结构可回忆起9,10-取代的蒽，并具有其吸收光谱和发光特性（室温下在乙醇和二氯甲烷溶液中以及在MeOH / EtOH（4：1 v / v）中）在77 K时）以及泵浦探头瞬态吸收光谱进行了分析，并进行了计算研究。该化合物具有各种装饰的嘧啶基作为蒽骨架的取代基。该化合物在两个系列方便地进行分组：1 - 4和11，其中，所述嘧啶氮原子存在于外侧相对于该蒽框架（EXT-型化合物），和5 -参见图10，其中嘧啶氮原子指向蒽平台（Int型化合物）。化合物12既包含具有“内部”氮原子（“ Int ”）的嘧啶取代基，又具有具有“外部”氮原子（“ Ext ”）的嘧啶取代基。所有这些新物种都是非常有效的发光体（最大发射光谱范围：在77 K时为400–450 nm；在室温下为415–520 nm；发射寿命：0.25–8.7 ns范围；发射量子产率在0.08至0.99之间，且单个例外），其光物理特性取决于嘧啶基与蒽基平台的连接方案（即，Int型vs Ext型化合物）。已经鉴定出源自局部激发的基于π-π*蒽的单线态，主要涉及嘧啶基部分的离域态和电荷转移态的发光。对于Int型序列，最初准备的激发态可以通过相互转换为马鞍形构型而失活，从而为快速的非辐射衰变开辟了道路。