This study designs and synthesizes a series of electron-donating monomers in an attempt to form exciplexes with known electron-withdrawing molecules, to investigate the influence of the chemical structure of monomers on the photophysical properties of exciplexes. The five designed electron-donating molecules exhibit intramolecular charge transfer effects. Changes in transition dipole moments were obtained using the Lippert-Mataga model, with values ranging from 17.6 to 28.6 D. Moreover, the electronic energy levels of these five molecules were estimated through molecular simulations and electrochemical potential measurements, providing the ground-state energies of the electron-donating molecules, which lie between the ground and excited-state energies of the electron-withdrawing molecules, thus enabling the formation of exciplexes. Those molecules were aggregated with two acceptor molecules, respectively, resulting in the formation of a new emission band, which indicates the existence of exciplex. We found that molecules with a triangular-like structure are more likely to form exciplex than rod-like molecules. Controlling the electronic energy levels of electron donor molecules can regulate the emission wavelength of the formed exciplexes. This report provides insights into monomer design and its impact on the desired photophysical properties of exciplexes, serving as a blueprint and guidance for molecular design in application-oriented product development.