Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Aug 1;6(8):4438-4444.
doi: 10.1039/c5sc00253b. Epub 2015 Apr 20.

Crystallization-induced dual emission from metal- and heavy atom-free aromatic acids and esters

Yongyang Gong  1 , Lifang Zhao  1 , Qian Peng  2 , Di Fan  2 , Wang Zhang Yuan  1 , Yongming Zhang  1 , Ben Zhong Tang  3   4
Affiliations

Crystallization-induced dual emission from metal- and heavy atom-free aromatic acids and esters

Yongyang Gong et al. Chem Sci. .

Abstract

Pure organic materials exhibiting room temperature phosphorescence (RTP) have significant fundamental importance and promising optoelectronic and biological applications. Exploration of metal- and heavy atom-free pure organic phosphors, however, remains challenging because achieving emissive triplet relaxation that outcompetes the vibrational loss is difficult without metal or heavy atoms. In this contribution, in contrast to aggregation-caused quenching (ACQ) normally observed in conventional chromophores, a unique phenomenon of crystallization-induced dual emission (CIDE), namely, simultaneously boosted fluorescence and phosphorescence upon crystallization, is observed in a group of pure organic aromatic acids and esters at ambient conditions. Moreover, two triplet-involved relaxations of delayed fluorescence (DF) and phosphorescence are activated. Such efficient intrinsic emission from both singlet and triplet states in a single compound without employing metal or heavy atoms is suitable for a variety of fundamental research and applications.

PubMed Disclaimer

Figures

Chart 1
Chart 1. Structure of aromatic acids and esters with CIDE characteristics studied in this work.
Fig. 1
Fig. 1. (A) Photograph of crystalline powders of TPA taken under 365 nm UV light. (B) PL spectra of TPA solution (20 μM in ethanol) and crystalline powders with t d of 0 and 0.5 ms. (C) Emission decay curves of crystalline powders of TPA monitored at 380 nm.
Fig. 2
Fig. 2. Photographs of IPA crystals under (A) room light, (B) 365 nm UV light and (C) just after stopping UV light. (D) PL spectra of IPA solution (20 μM in ethanol) and crystals with t d of 0 and 10 ms. (E) Emission decay curves of IPA crystals monitored at (E) 380 and (F) 506 nm.
Fig. 3
Fig. 3. Photograph of TFTPA crystals under 365 nm UV light. (B) PL spectra of TFTPA solution (20 μM in ethanol) and crystals with t d of 0 and 0.1 ms. (C) Emission decay curves of TFTPA crystals monitored at 484 and 367 nm (inset).
Fig. 4
Fig. 4. Perspective view of molecular packing arrangement in (co)crystals of (A) TPA, (B) IPA and (D–F) TFTPA–H2O. (C) Cocrystal structure of TFTPA–H2O with multiple intermolecular interactions. Intermolecular interactions are denoted by dotted lines.
Fig. 5
Fig. 5. Photographs of DMTFTPA taken under (A) room light and (B) 300 nm UV light. PL spectra of (C) DMTPA and (E) DMTFTPA solutions (20 μM in ethanol) and crystals with t d of 0 and 0.1 ms. Emission decay curves of (D) DMTPA and (F) DMTFTPA monitored at 350/420 and 354/484 nm, respectively.
Fig. 6
Fig. 6. Perspective view of molecular packing arrangement in crystals of (A) DMTPA and (C–E) DMTFTPA. (B) Crystal structure of DMTPA with multiple intermolecular interactions. Intermolecular interactions are denoted by dotted lines.
Fig. 7
Fig. 7. Calculated energy diagram and spin–orbital coupling of TPA in gas phase (left) and crystalline (right) state.
Fig. 8
Fig. 8. Schematic illustration of the CIDE phenomenon: (A) highly active molecular motions induced weak fluorescence in solutions and (B) conformation rigidification boosted both fluorescence (prompt and delayed) and phosphorescence in crystals.
See this image and copyright information in PMC

References

    1. Ma Y., Zhang H., Shen J., Che C. Synth. Met. 1998;94:245.
    2. Baldo M. A., O'Brien D. F., You Y., Shoustikov A., Sibley S., Thompson M. E., Forrest S. R. Nature. 1998;395:151.
    3. Adachi C., Baldo M. A., Thompson M. E., Forrest S. R. J. Appl. Phys. 2001;90:5048.
    1. Zhang G., Palmer G. M., Dewhirst M. W., Fraser C. L. Nat. Mater. 2009;8:747. - PMC - PubMed
    2. Han Y., You Y., Lee Y. M., Nam W. Adv. Mater. 2012;24:2748. - PubMed
    3. You Y., Han Y., Lee Y.-M., Park S. Y., Nam W., Lippard S. J. J. Am. Chem. Soc. 2011;133:11488. - PMC - PubMed
    4. You Y., Lee S., Kim T., Ohkubo K., Chae W.-S., Fukuzumi S., Jhon G.-J., Nam W., Lippard S. J. J. Am. Chem. Soc. 2011;133:18328. - PMC - PubMed
    5. Zhao Q., Li F., Huang C. Chem. Soc. Rev. 2010;39:3007. - PubMed
    1. Xiong L., Zhao Q., Chen H., Wu Y., Dong Z., Zhou Z., Li F. Inorg. Chem. 2010;49:6402. - PubMed
    2. Zhao Q., Yu M., Shi L., Liu S., Li C., Shi M., Zhou Z., Huang C., Li F. Organometallics. 2010;29:1085.
    1. Wong W.-Y., Ho C.-L. Acc. Chem. Res. 2010;43:1246. - PubMed
    2. Lee C.-L., Hwang I.-W., Byeon C. C., Kim B. H., Greenham N. C. Adv. Funct. Mater. 2010;20:2945.
    3. Luhman W. A., Holmes R. J. Appl. Phys. Lett. 2009;94:153304.
    1. Evans R. C., Douglas P., Winscom C. J. Coord. Chem. Rev. 2006;250:2093.
    2. Au V. K.-M., Wong K. M.-C., Tsang D. P.-K., Chan M.-Y., Zhu N., Yam V. W.-W. J. Am. Chem. Soc. 2010;132:14273. - PubMed