The Synthesis Of Probes Based On The Benzimidazole Naphthalimide Derivatives And Their Properties Research

Based on the fluorophore of benzimidazo[2,1-a]benz[de]isoquinoline-7-one though introducing different complex groups on the C-10,C-11 and C-12 position,we have prepared ten derivatives of Benzimidazole naphthalimide:N-butyl-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinoline-11-carbothioamide(D1),12-((tert-butyldiphenylsilyl)oxy)-7H-be-nzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D2),10-(2-imine thiourea-2-phenyl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D3),11-(2-imine thiourea-2-phenyl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D4),10-(2-(2-Nitrophenylhydrazi-ne)methylene-2-phenyl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D5),11-(2-(2-Nitrophenylhydrazine)methylene-2-phenyl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoq-uinolin-7-one(D6),10-(2-(4-Nitrophenylhydrazine)methylene-2-phenyl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D7),11-(2-(4-Nitrophenylhydrazine)methylene-2-phen-yl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D8),10-(2-(2,4-Dinitrophenylh-ydrazine)methylene-2-phenyl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D9),11-(2-(2,4-Dinitrophenylhydrazine)methylene-2-phenyl)-7H-ben-zo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one(D10).The structures of the above probes were validated by 1H NMR,13C NMR and HRMS-ESI,and their optical properties were investigated by fluorescence emission spectra and UV-vis absorbance.We discovered that D1-D6 could be used to detect Hg2+,F-in aqueous solution and DMSO soulation.In acetonitrile/water(7:3)solution,D1 displays good selectivity and sensitivity for Hg2+via Hg2+-promoted selective desulfurization reaction,Hg2+-induced transformation from the thiocarbonyl group to the carbon one followed by the removal of the HgS caused the fluorescence enhancement.The fluorescence intensity of D1 with Hg2+ was stable over a wide pH range(7.0-11.0).In DMSO solution,basising of F--triggered Si-O bond cleavage and the concomitant release of fluorophores,probe D2 displays good selectivity and sensitivity for F-.The probe D2 not only showed fluorescence quenching towards F-,but also showed a significant 225 nm red-shifted of the absorption maximum,accompanying with a yellow-to-blue color change.In the same condition,D3 and D4 showed remarkable selectivity and specificity toward F-over other anions.Addition of F-to D3 and D4 resulted in quenching of fluorescence.D3 accompanied with a light yellow-to-orange color change.D4 accompanied with a light yellow-to-purple color change.The spectral responses of D3 and D4 along with a visible color change could be switched back and forth by successively adding F-and HSO4-into their DMSO solutions,which indicated probes D3 and D4 were stable and could be used in reversible manner.In DMSO solutions,D5 and D6 displayed a high selectivity and sensitivity toward F-over other anions,with a significant 155 nm and 195 nm bathochromic shift of the absorption maximum.Meanwhile,it could be easily observed that the probes for F-changed from orange to blue-green by the naked eye,and with fluorescence enhancement after the F-was added.In the same condition,D7-D10 displayed a bad selectivity toward F-over other anions,In D7 and D8 solution,CN-could also cause spectral changes.In D9 and D10 solution,CN-,AcO-and H2PO4-were able to result in spectral changes.