Regioisomers of Organic Semiconducting Dumbbell‐Shaped Molecules: Synthesis and Structure‐Properties Relationship

Two new dumbbell-shaped molecules based on two solubilizing and structuring triazatruxene (TAT) units linked by a central chromophore were synthesized studied. The was an electro-deficient fluorene-malononitrile (FM) unit, that can be functionalized symmetrically different positions, giving rise to positional isomers, called TAT-pFM TAT-mFM, when the TATs are connected 2,7- 3,6-positions, respectively. isomers exhibited electronic conjugation pathways drastically affect their absorption properties energy levels. Moreover, while organized in stable 3D mesomorphic structure from room-temperature melting point, TAT-mFM remained crystalline decomposed before melting. Finally, despite lower hole mobility, highest Power Conversion Efficiency (PCE) of about 2 % organic solar cells. This higher PCE attributed essentially pronounced internal charge transfer band contribution photogeneration observed