Determination of Molecular Dipole Moment by a Dual‐Solute Method

The dipole moment is an important parameter of molecular structure, playing a crucial role in determining the spatial structure of molecules and understanding the distribution of charges and symmetry within molecules. Building upon the traditional solution‐based experimental approach, our study proposes a simple yet effective enhancement strategy to enable the dipole moment determination of challenging molecules that are poorly soluble or insoluble in nonpolar solvents by introducing polar medium to form a dual‐solute solution. The experimental results show that the relative error compared to literature values is within 5%, and the method requires only a very small amount of sample per measurement, making it environmentally friendly, widely applicable, and low‐cost. In addition, combined with the improvement of the capacitance meter, this method serves not only as an alternative for measuring the dipole moment of strongly polar molecules but also for investigating the dynamic polarity changes during the isomerization process of light‐responsive molecules.