Diarylamino Groups as Photostable Auxofluors in 2‐Benzoxazolylfluorene, 2,5‐Diphenyloxazoles, 1,3,5‐Hexatrienes, 1,4‐Distyrylbenzenes, and 2,7‐Distyrylfluorenes.

Abstract

The relationship of structure to optical spectral properties was determined for five types of fluors in a search for an optimum-wavelength shifter to be used as part of the detection systems for high-energy particles from accelerators. In a search for photostable fluors to serve as waveshifters in plastic fibers it was found that the wavelengths of interest, absorption max 410 ± 10 nm and fluorescence emission max 480 ± 20 nm, along with other properties, such as high solubility and short fluorescence decay time, could be obtained from fluorophors composed of aromatic rings and vinyl groups only by using amino groups as auxochromes to give bathochromic shifts of wavelengths. Since primary, monoalkyl, and dialkylamino groups were not sufficiently photostable, a number of fluorophores bearing diarylamino groups were investigated. Syntheses of the fluors made use of the Buchwald amination, an improved version of the Emmons−Horner reaction, and other common reactions. The fluor types were the following: a 2-...