Three-dimensional architectures for highly stable pure blue emission

Four three-dimensionally architectured molecules 1a-d with spiro-annulated structural features were facilely developed. 1a and 1b form uniform and amorphous films via spin-coating due to their rigid three-dimensional architecture. The PL spectra of 1a-d exhibit 0 excellent thermal stability upon air annealing. Their blue color integrity remained after continuous annealing for 12 h at 200 C in the air. OLED fabrication reveals that all 1a-d exhibit pure blue EL performance and good color integrity at different operating voltages.