Molecular Engineering for the Development of a Discotic Nematic Mesophase and Solid-State Emitter in Deep-Blue OLEDs.

A unique strategy for the attainment of a discotic nematic (N _D ) mesophase is reported consisting of a central benzene core to which are attached two 4-alkylphenyl and two 4-pentylbiphenyl moieties diagonally via alkynyl linkers. The rotational nature and incompatibility of unequal phenylethynyl units led to the disruption of π-π interactions within cores that aids to the realization of N _D phase and favors high solid-state emission. When used in OLEDs, compounds act as an efficient solid-state pure deep-blue emitter with Commission Internationale de L'Eclairage (CIE _{x , y} ) coordinates of (0.16, 0.07).