Synthesis, Characterization, and Photophysical Properties of Novel BODIPY and

Abstract

In this study, novel homoleptic BF2 and Zn (II) complexes derived from an asymmetric dipyrromethene ligand were synthesized, with their chemical structures elucidated through NMR, and HRMS techniques. The photophysical characteristics in solution were investigated utilizing UV-visible absorption and fluorescence spectroscopy. The experimental results are clarified through Density Functional Theory (DFT) calculations and electron-hole analysis. Theoretical analyses have demonstrated that, following excitation, both electrons and holes remain confined exclusively within the BODIPY core. The charge-transfer transitions were identified between reciprocal ligands, which are responsible for the redshift observed in the main absorption band, as evidenced by electron-hole analysis. The energy levels of the frontier molecular orbitals converge contingent upon the incorporation of naphthyl and p-methoxyphenyl substituents. When analyzed under an inert nitrogen atmosphere, the compounds exhibited considerable thermal stability. Despite the similarity in the TGA curves of the complexes, the formation of the homoleptic complex resulted in an enhancement in degradation temperatures. This study indicates that chromophoric dipyrromethene complexes present advantageous prospects for advancing the development of novel materials that are both photostable and thermostable, effectively integrating charge transfer with low energy within the visible and/or near-infrared spectra.