2,5‐Dimethoxybenzene‐1,4‐dicarboxaldehyde: An Emissive Organic Crystal and Highly Efficient Fluorescent Waveguide

• Published in: ChemPlusChem (Weinheim, Germany) Vol. 84; no. 3; pp. 247 - 251
• Main Authors: Hayashi, Shotaro, Koizumi, Toshio, Kamiya, Natsumi
• Format: Journal Article
• Language: English
• Published: Germany 01.03.2019
• Subjects: donor-acceptor systems; fluorescence; hydrogen bonds; optical waveguides; photochemistry; donor-acceptor systems; optical waveguides; fluorescence; photochemistry; hydrogen bonds
• ISSN: 2192-6506; 2192-6506
• DOI: 10.1002/cplu.201800597

To identify the simplest organic structure for an emitter, we focused on 2,5‐dimethoxybenzene‐1,4‐dicarboaldehyde. This symmetric molecule has a very low molecular weight (MW=194), a single benzene unit, and consists of only three elements (H, C and O). It forms highly efficient and pure emitting crystals (λem=499 nm, ΦF=0.42, FWHM=42 nm) due to the rigid structure based on the single benzene framework and four intramolecular hydrogen bonds between electron‐donating methoxy and electron‐accepting aldehyde groups. This crystal acts as a good optical waveguide with pure green emission (FWHM=34 nm) and very low loss coefficient (0.00120 dB/μm). A simple molecule, 2,5‐dimethoxybenzene‐1,4‐dicarboaldehyde, is symmetric, has a low molecular weight (MW=194) and contains a single benzene unit. Highly efficient emitting crystals were obtained from this molecule, and this efficiency is ascribed to the rigid structure. These crystals may serve as a good fluorescent waveguide with green fluorescence and a low loss coefficient.