Investigation of band gap of organic semiconductors by molecular modeling methods and computer aided drug design

Molecular modeling is all the theoretical and computerized methods used to model, study or simulate the behavior of molecular systems. These methods are mainly used to provide theoretical predictions for a molecular system, to explain the experimental results of a molecular system, and to examine the properties of macromolecular and complex structures. Today, the use of molecular modeling methods in materials science and drug design has become a necessity, and the efficient use of these methods before starting the experiment phase is important for the correct management of resources. This thesis consists of six studies divided into three parts. In the first part, semiconductor polymers were designed using molecular modeling methods and their structure-conductivity relationships were examined. In the first study in this part, alkyl substituted pyrrole-benzothiadiazole-pyrrole based conductive polymers were designed and their structural conductivity properties were investigated with theoretical approaches. In the second study, Donor-acceptor type polymers were designed using thieno[3,4-b]pyrazine, thieno[3,4-b]quinoxaline, 2H-pyrrolo[3,4-b]quinoxaline, 6H-pyrrolo[3,4-b]pyrazine donors and benzo[c][1,2,5]thiadiazole, naphtho[2,3-c][1,2,5]thiadiazole acceptors. In the second part, some small molecule semiconductors have been designed for photovoltaic applications and the photovoltaic properties of small molecule semiconductors having energy transfer properties were investigated. In the first study in this part, a donor-acceptor-donor type semiconductor small molecule design using thiophene donors, phthalimide, benzimidazole and benzotriazole acceptors was made and its photovoltaic properties were investigated. In the second study in this part, photovoltaic properties of synthesized porphyrin-BODIPY diads with energy transfer properties were investigated. In the last part of the study, computer aided drug design was studied. In this context, the properties of two different biochemical systems were evaluated. In the first study, the efficacy of some synthesized indole, benzimidazole and benzotriazole-based ketonic compounds in the treatment of Alzheimer's disease were investigated. In the second study of this part, the interactions of indole-based compounds with the target protein 𝛼-glucosidase in the treatment of diabetes were investigated.