Investigation of photophysical properties of triphenylamine phenylethenyl derivatives containing tertiary amine groups

Abstract

Triphenylamine (TPA) compounds are versatile charge transport materials, demonstrating high emission efficiency and interesting interactions in solid state. Their spectroscopic emission parameters highly depend on surrounding medium owning to strong CT character in solution. Although TPA compounds demonstrate good charge transport capabilities, further optimization via molecular design is required. In this work, various TPA molecular systems with varying number of additional dimethylamine (dMA) and phenylethenyl (PE) substituents were thoroughly investigated. Additionally, influence of quaternarization of tertiary amine groups in the triphenylamine backbone on emission and electronic properties was analyzed. TPA-dMA compounds demonstrated aggregation induced emission enhancement with high emission efficiency and excellent (μh = 4.7·10−3 cm2V−1s−1) charge transport in the solid state. Quaternarization of tertiary amine groups in the triphenylamine backbone has led to emission and electronic properties in the wide 400–700 nm spectral region.