1,1'-biferrosenilen içeren donör-akseptör (D-A) sistemlerin sentezleri ve özellikleri

Fused heterocyclic molecules with high π-delocalization such as thienothiophenes (TTs) and dithienothiophenes (DTTs), have been attracting great attention as building blocks for the construction of organic semiconductors for organic light emitting diodes (OLEDs), organic field-effect transistors (OFETs), organic solar cells (OSCs) and photovoltaic cells. In comparison to traditional materials used in photovoltaics, the growing interest comes from their relatively easier synthetic strategies, well-defined molecular structures, easier purification methods, better proccessibility and reproducibility. Since the electronic properties of materials exceedingly depend on their electronic energy levels, adjusting the energy levels and band gap size is pivotal in the design and synthesis of efficient materials. The use of strong donor (D) and acceptor (A) units is the most effective way to design low band gap materials. In D−A systems, both electron accepting and donating groups decrease Eg. The electron-accepting unit reduces the LUMO (Lowest Empty Molecular Orbital) energy, while the electron-donating group raises the HOMO (Highest Empty Molecular Orbital) level. Thiophene derivatives are now excellent candidates for a variety of advanced material applications owing to their electron-rich characters and good chemical and thermal stabilities. In this thesis, alkyl-substituted TT used for enhancing solubility and as a π-spacer was synthesized using a novel method. In our method, it can be synthesized in lower steps and higher yield as compared with literature. The synthesis of materials composed of electron-donating (D) and -accepting (A) units offer the ability to manipulate the HOMO−LUMO energy levels. The electron- donating group is 1,1′-biferrocenylene (BFD), which has a mixed-valence class III character for the BFD0/BFD+ redox stage. On the other side, benzothiadiazole (BT) and thieno[3,2-b]thiophene that has benzonitrile are strong acceptors and utilized for designing low HOMO–LUMO gap.