Theoretical study of chemosensor for fluoride anion and optical properties of the derivatives of diketopyrrolopyrrole

Abstract

The interactions between chemosensors, diketopyrrolopyrrole (DPP) derivatives, and different halides (F−, Cl−, and Br−) anions have been theoretically investigated using DFT approaches. Theoretical investigations have been performed to explore the optical, electronic, charge transport, and stability properties of DPP derivatives as charge transport and/or luminescent materials. It turned out that the unique selectivity of DPP derivatives for F− is ascribed to their ability of deprotonating the host sensors. The atoms in molecules theory and natural bond orbitals charge analysis of the complexes consisting of DPP derivatives and X− (X = F, Cl, and Br) confirm that the protons are almost completely abstracted by F−. The study of substituent effects suggests that all the substituted derivatives are expected to be promising candidates for ratiometric fluorescent fluoride chemosensors as well as chromogenic chemosensors. Furthermore, the derivatives with biphenyl, 2-(thiophen-2-yl)thiophene, and benzo[d]thieno[3,2-b]thiophene fragments are expected to be promising luminescent materials. In addition, derivatives with 2-(thiophen-2-yl)thiophene and 4,9-dihydrothieno[3,4-b]quinoxaline fragments can serve as good electron transport materials for OLEDs as well.