A new pH sensitive fluorescent and white light emissive material through controlled intermolecular charge transfer† †Electronic supplementary information (ESI) available: Text: experiments, characterization, devices fabrication. Figures: NMR, titration curve, estimation of pK a, single quantum mode fit, absorption/PL spectrum in pH 2/12, different orbitals for molecule A, half-occupied natural orbitals, PL spectra of ATAOPV at different concentrations under different pH, experimental and calcula

• Published in: Chemical science (Cambridge) Vol. 6; no. 1; pp. 789 - 797
• Main Authors: Park, Y. I., Postupna, O., Zhugayevych, A., Shin, H., Park, Y.-S., Kim, B., Yen, H.-J., Cheruku, P., Martinez, J. S., Park, J. W., Tretiak, S., Wang, H.-L.
• Format: Journal Article
• Language: English
• Published: Royal Society of Chemistry 10.09.2014
• Subjects: Chemistry
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c4sc01911c

Fabrication of a unique white light LED from a stimuli-responsive organic molecule is reported. Emission properties are dominated by the pH of the solution through intermolecular charge transfer. A new, pH dependent and water-soluble, conjugated oligomer (amino, trimethylammonium oligophenylene vinylene, ATAOPV ) was synthesized with a quaternary ammonium salt and an aromatic amine at the two ends of a π-conjugated oligomer, thus creating a strong dipole across the molecule. A unique white light LED is successfully fabricated from a stimuli responsive organic molecule whose emission properties are dominated by the pH value of the solution through controlled intermolecular charge transfer.