Two bulky acridine moieties, 9,9-diphenyl-9,10-dihydroacridine (DPAc) and 10H-spiro [acridine-9,9′-fluorene] (SpiroAc), were selected as electron donors. Compared with commonly used 9,9-dimethyl-9,10-dihydroacridine (DMAc), phenyl modified acridines exhibited low-lying highest occupied molecular orbital (HOMO) levels and relatively weak electron-donating abilities, which make them potential units to create blue TADF emitter. DPAc and SpiroAc were connected with a triarylboron group and constructed centrosymmetric 3D-A architectures, namely 3DPAc-TB and 3SpiroAc-TB, respectively. Density functional theory calculations showed that both molecules exhibited large dihedral angles between the triarylboron unit and acridine planes. The well-separated frontier molecular orbitals contributed to small energy gaps between S₁ and T₁ states of the designed molecules (0.12 and 0.07 eV, respectively). Both molecules exhibited distinct thermally activated delayed fluorescence (TADF) character. The bulky acridine donors endowed both molecules with rigid structures and realized high photoluminescent quantum yields (71.6% and 84.3%, respectively). Solution-processed organic light-emitting diodes (OLEDs) utilizing 3DPAc-TB and 3SpiroAc-TB as emitters exhibited blue emissions with emission peaks of 472 nm and 490 nm, respectively. The maximum external quantum efficiencies of 3DPAc-TB and 3SpiroAc-TB based devices were 12.8% and 17.3%, respectively.

两个庞大的a啶部分，9,9-二苯基-9,10-二氢ac啶（DPAc）和10 H-螺环[ac啶-9,9'-芴]（SpiroAc）被选作电子供体。与常用的9,9-二甲基-9,10-二氢ac啶（DMAc）相比，苯基修饰的cr啶具有较低的最高占据分子轨道（HOMO）水平和相对较弱的给电子能力，这使其成为形成蓝色的潜在单元TADF发射器。DPAc和SpiroAc与三芳基硼基团相连，并分别构建了中心对称3D-A体系结构，即3DPAc-TB和3SpiroAc-TB。密度泛函理论计算表明，两个分子在三芳基硼单元和a啶平面之间均显示出较大的二面角。边界分子轨道的良好分隔有助于S ₁和T ₁之间的小能隙设计分子的状态（分别为0.12和0.07 eV）。两种分子均显示出独特的热激活延迟荧光（TADF）特性。庞大的a啶供体赋予两个分子刚性结构，并实现了高光致发光量子产率（分别为71.6％和84.3％）。使用3DPAc-TB和3SpiroAc-TB作为发射器的溶液处理有机发光二极管（OLED）表现出蓝色发射，发射峰分别为472 nm和490 nm。基于3DPAc-TB和3SpiroAc-TB的设备的最大外部量子效率分别为12.8％和17.3％。