shows emission from 627 to 654 nm and 4PXZ-TPPQ shows emission from 682 to 770 nm by varying doping concentration from 5 to 50 wt% in CBP and in neat film with lowering ∆EST to 0.29 and 0.04 eV, respectively (Figure and Table ). Finally, we fabricated doped (in CBP) and neat film solution-processed OLEDs (SP-OLEDs) of 4DAMC-TPPQ and 4PXZ-TPPQ. The neat film SP-OLEDs with 4DMAC-TPPQ emitted with an electroluminescence maximum, λEL, of 685 nm, while neat film SP-OLEDs with 4PXZ-TPPQ emitted at λEL of 780 nm. Notably, the PL spectrum of 4PXZ-TPPQ and the EL spectrum of the OLED with this emitter were the most red-shifted amongst the 19 other TADF emitters containing a quinoxaline-type acceptor (Figure and Table ). Remarkably, we also enabled the TADF phenomena in TPPQ containing emitters, which was absent in previously reported compounds containing the TPPQ moiety. ), rather than the previously encountered parallel sheet structure. There between one pyrazine ring and another phenyl of a DMAC (centroid•••centroid distance 3.8477 (11)). In the structure of 4PXZ-TPPQ, molecules show undulating layered packing, with channels for solvent (Figure ). This complex shows a more significant and more complex arrangement of supramolecular interactions. This comprises two-dimensional sheets in the (0 0 1) plane, built up of a combination of nine sets of interactions (Figure ). These include two sets of π•••π interactions from the central benzene ring while in 4PXZ-TPPQ the PXZ moieties are slightly less twisted (70.64 and 71.37°, Figure ). Moreover, the DMAC units retained their puckered/bowed conformations, with dihedral angles between the phenyl ring planes of 31.72° and 28.96°. Their conformation is well matched with that in the corresponding crystal structure; however, the PXZ units exhibited more planar conformations than seen in the crystal structure, with dihedral angles between their phenyl ring planes of 2.07° and 2.32°. The electron density of the highly occupied molecular orbital (HOMO) is delocalized over the whole TPPQ molecule, while the lowest unoccupied molecular orbital (LUMO) is somewhat more concentrated on the pyrazino[2,3-g]quinoxaline.