Tuning photophysical properties and electronic energy levels of 1-aminoanthraquinone derivatives by introducing N-ethyl substituent

It is proved that introducing the ethyl substituted group to 1-amino will enhance the intramolecular charge transfer ( ICT ) process of 1-N substituted anthraquinone derivatives. Bathochromic shift of the absorption maxima and diminished absorption intensity are observed with the increase of the electron donation abilities of the N-ethyl groups. Moreover, the intramolecular and intermolecular hydrogen bonds further intensify the ICT properties through introducing the end amino group. This work exhibits more effective acceptors than anthraquinone in novel multichromophore materials for organic solar cells and other optoelectronic devices.