A new type of light-emitting naphtho[2,3-c][1,2,5]thiadiazole derivatives: synthesis, photophysical characterization and transporting properties
作者:Peng Wei、Lian Duan、Deqiang Zhang、Juan Qiao、Liduo Wang、Ruji Wang、Guifang Dong、Yong Qiu
DOI:10.1039/b714539j
日期:——
We report a new series of naphtho[2,3-c][1,2,5]thiadiazole (NTD) derivatives which present both carrier transporting property and high fluorescence quantum yield. Optical absorption and emission property, film morphology and thermal stability of these compounds have been investigated. Due to the absence of a strong donor group in the molecular structure, intermolecular dipole–dipole interaction and concentration quenching are effectively suppressed. The emission color was found to be adjustable depending on the aryl substituents at the 4,9-position of the NTD chromophore. Single crystals of 4-(2,2-diphenylvinyl)phenyl-substituted NTD (1) and biphenyl-substituted NTD (3) were obtained and determined by X-ray crystallography. It was found that 1, 3 and 2-naphthalene-substituted NTD (5) show ambipolar transporting property with almost identical hole and electron mobilities. Notably, 1 shows extremely high transporting ability, whose hole and electron mobilities were measured to be 7.16 × 10−4 and 6.19 × 10−4 cm2 V−1 s−1 at an electric field of 2.0 × 105 V cm−1, respectively. Theoretical calculations showed 1, 3 and 5 have similar reorganization energies for holes and electrons, and holes and electrons would both hop between the adjacent NTD chromophores, resulting in the ambipolar transporting property. Double-layer non-doped devices were fabricated with some of the NTD derivatives, and the correlations between device performance and molecular structure were also discussed.
我们报告了一系列新的萘并[2,3-c][1,2,5]噻二唑(NTD)衍生物,它们同时具有载流子传输特性和高荧光量子产率。研究人员对这些化合物的光学吸收和发射特性、薄膜形态和热稳定性进行了研究。由于分子结构中没有强供体基团,分子间偶极-偶极相互作用和浓度淬灭被有效抑制。研究发现,NTD 发色团 4,9 位上的芳基取代基可以调节发射颜色。获得了 4-(2,2-二苯基乙烯基)苯基取代的 NTD(1)和联苯取代的 NTD(3)的单晶体,并通过 X 射线晶体学进行了测定。研究发现,1、3 和 2-萘取代的 NTD(5)具有几乎相同的空穴和电子迁移率,显示出两极传输特性。值得注意的是,1 显示出极高的传输能力,在 2.0 × 105 V cm-1 的电场下,其空穴和电子迁移率分别为 7.16 × 10-4 和 6.19 × 10-4 cm2 V-1 s-1。理论计算表明,1、3 和 5 具有相似的空穴和电子重组能量,空穴和电子都会在相邻的 NTD 发色团之间跳跃,从而产生伏极传输特性。研究人员利用其中一些 NTD 衍生物制造了双层非掺杂器件,并讨论了器件性能与分子结构之间的相关性。