New AIEgens based on thieno[2,3-d]pyrimidine derivatives: Synthesis, DFT calculations, and molecular docking

Abstract

In this paper, new thieno[2,3-d]pyrimidine analogs have been synthesized and characterized through different spectroscopic techniques. The photophysical properties of the molecules (7b-7f) and the quantum chemical calculations have been investigated. These molecules exhibited aggregation-induced emission behavior and showed efficient emission in both solid and solution states. A shift toward shorter wavelengths (hypsochromic shift) was observed when transitioning from the solution to the solid state, which could be explained by photoinduced intramolecular charge transfer (ICT) processes. DFT calculations confirmed that the diverse behavior of the thieno[2,3-d]pyrimidine analogs could be attributed to variations in molecular packing and rigidity. This study illustrates how luminophores aggregation can occur without significantly impacting the excited state, emphasizing the unconventional behavior resulting from minor alterations in terminal substituents. These findings hold implications for the advancement of luminescent materials. Additionally, theoretical calculations were conducted to compare the excitations and emissions of the new AIEgens with practical observations. Furthermore, a molecular docking study of the five AIEgens suggested their potential utility as anticancer drugs. Compound 7c exhibited a high affinity for human cyclin-dependent kinase 2 (CDK-2) protein, with a binding energy of 9.6 kcal/mol, indicating its potential as an inhibitor for this specific protein.