Donor–Acceptor–Donor 1H-Benzo[d]imidazole Derivatives as Optical Waveguides

A new series of donor–acceptor–donor (D–A–D) structures derived from arylethynyl 1H-benzo[d]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(−2) 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 1H-benzo[d]imidazole derivatives appealing compounds for optical waveguide applications.