Linear and V-shaped push–pull systems on a base of pyrimidine scaffold with a pyrene-donative fragment for detection of nitroaromatic compounds

New fluorophores based on pyrimidines, bearing a pyrene electron-donating fragment, have been designed, synthesized and characterized. The fluorescence behavior of these fluorophores has been evaluated toward nitroaromatic compounds, including such well-known explosives, as 2,4-dinitroanisole, picric and styphnic acids, 1,3,5-triethoxy-2,4,6-trinitrobenzene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, 2,4,6-triamino-1,3,5-trinitrobenzene and nitrobenzene. The detection limits for these fluorophores in relation to nitroaromatic compounds in acetonitrile solution proved to be in the range from 10−1 to 10−7 mol/L. The sensor prototypes for handheld sniffer «Nitroscan» (Plant «Promautomatika», Ekaterinburg, Russia) based on these fluorophores have been fabricated and used for applications, as illustrated by reusable, reversible and sensitive fast detection of nitrobenzene and 2,4,6-trinitrotoluene in vapor phase concentrations up to 6 and 5 ppb, respectively.