Two new easy-to-access TADF emitters have been synthesised in good yields. The A-D-A emitter DIDOBNA-N showed efficient pure blue emission and TADF in 1.5 wt% TSPO1 films (lPL = 444 nm, FWHM = 64 nm, FPL = 81%, td = 23 µs). The electroluminescence is blue-shifted (lEL = 429 nm, FWHM = 70 nm, CIEy = 0.073), corresponding well to the NTSC standard of (0.14, 0.08). The OLED shows an excellent EQEmax of 15.3%, which is the highest reported for a deep blue emitter with a lEL<430 nm. The MR-TADF emitter, MesB-DIDOBNA-N was obtained from DIDOBNA-N in one step by installing a bridging mesitylated borane unit. This compound represents a rare example of a non triangulene type π-extended violet MR-TADF emitter. The molecular design utilized two electronically distinct acceptor boron atoms in combination with mixed donor nitrogen, and oxygen atoms.