Influence of Aliphatic Substituents on the Properties of 2,1,3-Benzothiadiazole-Based Luminophores

In this work, a series of 2,1,3-benzothiadiazole (BTD)-based organic luminophores which include 2,5-thiophene and 1,4-benzene moieties and terminal alkyl chains in their structures were synthesized. The effect of the length of the alkyl chain on the solubility, optical and thermal properties of the resulting luminophores was investigated. The introduction of alkyl substituents leads to a slight bathochromic shift of the absorption and luminescence maxima compared to their unsubstituted analog. As the length of the aliphatic chain increases, the melting point of the BTD-based luminophores decreases. The length of the aliphatic chain strongly affects the solubility of the molecules obtained.