Solvatochromic Study of Brilliant Blue G: Estimation of the Electric Dipole Moment in the Excited State

Brilliant blue G is a chemical compound with many important applications in various domains, from dye manufacturing to biotechnologies and medicine. Despite the fact that it is used mainly in solutions, a solvatochromic study of this compound has never been reported, while the value of the electrical dipole moment in the excited state is unknown. Here, a solvatochromic study of brilliant blue G is described, and the data is analyzed by three models, allowing for the estimation of the intermolecular interactions involved, as well as their contribution to the total shift in the visible electronic absorption spectral band. Two models provide a predominance of the non-specific (universal) intermolecular interactions, while the third model overestimates the weight of the specific interactions. The spectral data also allow for the comparative estimation of the electrical dipole moment in the first excited state of brilliant blue G molecule by two methods. The values obtained are very close, confirming the good agreement between the two approaches. One of these methods also estimates the angle between the electrical dipole moments in the ground and excited states of brilliant blue G molecule, respectively.