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

Abstract

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∼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∼3 times higher.

Keywords:

• Bis(dipyrrinato)zinc complex
• OLED
• π-π* stacking
• yellow-green emitting material

Acknowledgments

This research was supported by a grant (Catholic Univ.) from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy (MKE), Republic of Korea. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (No. 20090080199). This study was supported by a grant (Hanyang Univ.) from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy (MKE), Republic of Korea. This work was supported by the Technology Innovation Program funded by the Ministry of Knowledge Economy (MKE, Korea). This study was supported by a grant from the Strategy Project funded by the Ministry of Knowledge Economy (MKE), Republic of Korea.

Notes

^a Solution 1 × 10⁻⁵ M in THF.

^b On glass (thickness: 30 nm).

CIE*: Commission Internationale de l'Eclairage.