Donor-Acceptor-Donor 1-Benzo[]imidazole Derivatives as Optical Waveguides.

A new series of donor-acceptor-donor (D-A-D) structures derived from arylethynyl 1-benzo[]imidazole was synthesized and processed into single crystals with the goal of testing such crystals' ability to act as optical waveguides. Some crystals displayed luminescence in the 550-600 nm range and optical waveguiding behavior with optical loss coefficients around 10 dB/μm, which indicated a notable light transport. The crystalline structure, confirmed by X-ray diffraction, contains internal channels that are important for light propagation, as we previously reported. The combination of a 1D assembly, a single crystal structure, and notable light emission properties with low losses from self-absorption made 1-benzo[]imidazole derivatives appealing compounds for optical waveguide applications.