Enforced Effects of Side Group Substitution Position on Luminescence Properties; Synthesis of Bis(dipyrrinato)zinc Complex Derivatives

New yellow-green emitting materials using bis(dipyrrinato)zinc complex moiety were synthesized by substituting phenyl group and 1- or 2-positioned naphthalene group. Bis[5-(1-naphthalenyl)-dipyrrinato]zinc complex (Zn(1-NaPN)(2)) substituted at position 1 of naphthalene group showed about 10 times stronger photoluminescence (PL) property and sharper PL spectrum compared to bis[5-(phenyl)-dipyrrinato]zinc complex (Zn(PPN)(2)) and bis[5-(2-naphthalenyl)-dipyrrinato]zinc complex (Zn(2-NaPN)(2)). Optical properties in film state were almost identical to the result of non-doped organic light emitting diodes (OLEDs) device. Luminance efficiency (cd/A) of Zn(1-NaPN)(2) was 0.33 cd/A, which was about 4 similar to 8 times higher than Zn(PPN)(2), 0.04 cd/A and Zn(2-NaPN)(2), 0.08 cd/A. Quantum efficiency was also about 2 similar to 3 times higher.