TDDFT Study of the Influence of C20 Fullerene on Optical Properties of BODIPY and Two its Analogs: AlDIPY, GaDIPY

In this research, it is tried to improve electrical, optical, and non-linear optical (NLO) properties of boron-dipyrromethene (BODIPY) as a very optically active molecule. The results showed that two analogs of BODIPY, i.e., the AlDIPY and GaDIPY, have electrical properties and optical activity comparable to those of BODIPY. Next, improvement of the electrical and optical properties of BODIPY, AlDIPY, and GaDIPY was investigated using the C20 fullerene, as an electronegative fragment, instead of two F atoms. The results showed considerable improvement in the electrical properties of these molecules. Compatible with high electronegativity of C20 fullerene, evident charge transfer (CT) from BODIPY, AlDIPY, and GaDIPY to C20 fullerene was seen. Promising results were observed when using the C20 to modify the optical properties of BODIPY, AlDIPY, and GaDIPY. In particular, the optical properties of BODIPY were enriched in the presence of C20. This molecule causes the creation of two absorption lines in visible region that did not exist before. The solvent influence on the optical activity of BODIPY-C20 showed that, in the visible region, the λmax line is affected by the polarity of the solvent and increasing solvent dielectric constant cause a blue shift in this region. Finally, the NLO properties were calculated for all mentioned molecules, which indicated remarkable improvement in the NLO properties in the presence of C20 fullerene. The results of this research showed that the designed molecules are suitable for photosensitizer uses because of their NLO properties.