Synthesis Of Some New Fluorescence Probes And Studies On Fluorescence Character

Fluorescence probes are excellent sensors for biomolecules, being sensitive, fast-responding, and capable of affording high spatial resolution via microscopic imaging. Recently, many fluorescence Probes employing fluorescein as the core have been developed. They have been used in the detection of a variety of protein, nucleic acid, cell, HIV-1 nucleocapsid etc.Recently, we demonstrated that the fluorescein molecule could be understood as a directly linked donor-acceptor system. The two parts are conjugatively uncoupled since they are orthogonal to each other, and their fluorescence properties can be modulated by intramolecular photoinduced electron transfer (PeT) from the benzene moiety to the acceptor fluorophore (acceptor-excited PeT;a-PeT). It is reported that the fluorescence quantum yield of fluorescein derivatives was depended on the oxidation potential and the HOMO energy level of the benzene moiety. Almost all the currently known electron donor are the benzene moiety, and little are the heteroatromatic moiety.In the interest of the fluorescein derivatives involving heteroatromatic, we designed a facile and efficient synthetic route. First ten new potential applied foreground compounds (2,4-dihydroxyphenyl)-(5-methyl-1 -aryl- 1H-1,2,3-triazol-4-yl)methanone derivatives were synthesized with 5-methyl-l-aryl-1H-l,2,3-triazol-4-carboxylic acid acyl chlorine which was from aromatic amine, and resorcinol by Friedel-Crafts reaction. Then ten new high fluorescence quantum yield compounds 9-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)-6-hydroxy-3H-xanthen-3-one were synthesized by condensation with (2,4-dihydroxyphenyl)-(5-methyl-l-aryl-1H-1,2,3-triazol-4-yl)-methanone and resorcinol at fusing in the catalytic agent. Their fluorescence properties was studied in the EtOH and 0.1N NaOH, and the crystal structure of 9-(1-(3-chlorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-6-hydroxy-3H -xanthen-3-one was established by x-ray diffraction method.