Optical Properties of Chromophores with Different Six-Membered N-Heterocyclic Aromatic Ring

Abstract

A series of intramolecular charge transfer (ICT) molecules containing six-membered N-heterocyclic electron acceptors, as well as their phenyl analogue, have been synthesized. The pyrazine derivatives exhibit the largest quantum yield, stokes shift and the longest emission maxima wavelength due to the appropriate electronegativity of pyrazine, while the triazine derivative has much lower quantum yield due to its too strong ICT. The methyl groups at N-heterocyclic rings also have influence on the optical properties by disturbing the molecular dipole moment.