A series of D-​π-​A- type dyes based on pyrimidines, bearing various thiophene linkers, have been studied as sensing fluorophores. Fluorescence studies have demonstrated that the emission of all derivs. is sensitive to the presence of nitroarom. explosives, such as 2,​4,​6-​trinitrophenol (PA)​, 2,​4,​6-​trinitrotoluene (TNT)​, and 2,​4-​dinitrotoluene (DNT)​, in their acetonitrile solns. The detection limits of fluorophores to PA, TNT, and DNT proved to be in the range from 5.83 × 10-​6 to 2.38 × 10-​7 mol​/L, 1.70 × 10-​4 to 8.40 × 10-​6 mol​/L, and 8.39 × 10-​5 to 6.87 × 10-​6 mol​/L, resp. The theor. investigation into the quenching mechanism in the presence of fluorophore has been performed. All compds. have shown a good efficiency as sensor materials when tested as elements of the original device Nitroscan for detecting nitro-​contg. explosives in vapor phase