Diketopyrrolopyrrole (DPP) compounds, initially developed as high-performance red pigments, have gained significant attention in recent years due to their remarkable optical, electronic, and structural properties. These characteristics make DPP derivatives highly attractive for a wide range of applications, including organic electronics, photovoltaics, sensors, and bioimaging. The core DPP structure offers a versatile scaffold that can be chemically modified to fine-tune solubility, stability, and intermolecular interactions, thereby expanding their functional potential.

In this work, we present a study on a series of thienyl-substituted DPP derivatives, where targeted modifications have been introduced by varying the alkyl chains attached to the nitrogen atoms of the DPP core. These structural variations influence the molecular packing, solubility, and optoelectronic behavior of the resulting compounds, which are critical parameters for device integration.

A key innovation in our approach is the application of microwave-assisted synthesis, which significantly enhances the efficiency and sustainability of the synthetic process. Unlike conventional heating methods, microwave irradiation enables significantly shorter reaction times (just 40 minutes compared to 12 hours), higher yields (up to 80% for long alkyl chains), and reduced energy consumption, aligning with green chemistry principles.

Our results highlight the effectiveness of combining molecular engineering with advanced synthetic techniques to produce DPP-based materials in a more environmentally friendly and time-efficient manner. This study provides valuable insights into structure–property relationships in DPP systems and offers a promising route for the development of next-generation organic semiconductors.