Two novel thieno[3,4-b]pyrazine-cored molecules, P-DTP and TP-DTP, are synthesized and are characterized by extra large Stokes shifts of over 300 nm. The bulky polyaromatic arms enable these molecules to be solution processible and provide site-isolation on the planar emissive core. They exhibit saturated red electroluminescence in nondoped organic light-emitting diodes fabricated by spin coating.