ORGN 716 |
| The design and synthesis of new receptors for selective nitrate complexation and sensing is an area of extensive interest due to the environmental and forensic importance of nitrate salts, which are well known explosives. Herein we report the synthesis and anion binding properties of a fluorescent dansylamide sensor derived from 1,3,5-tris-(aminomethyl)-2,4,6-triethylbenzene (1) by 1H-NMR, fluorescence, FT-IR, and mass spectrometry. 1H-NMR titrations of 1 with tetrabutylammonium salts Bu4N+X- (X = Cl-, Br-, I-, NO3-) showed downfield shifts of the N-H resonance due to hydrogen bonding to the bound anion. The association constants for the formation of anion-receptor complexes were determinded by non-linear regression analysis of the titration curves and incicated selective binding for NO3- (146 M-1) over Cl- (43 M-1), Br- (91 M-1) and I- (15 M-1). Atmospheric Pressure Chemical Ionization Mass Spectrometry (APCI-MS) in the anion detection mode showed the formation of the [1.NO3]- complex (m/z = 1010) along with the [1-H]- peak for the deprotonated dansylamide at m/z = 947. Fluorescence Job plots indicated 1:1 complex formation. FT-IR confirmed anion complexation via hydrogen bonding.
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Asymmetric Reactions, Molecular Recognition, Self Assembly, Bioorganic Chemistry, Process R&D
8:00 PM-10:00 PM, Wednesday, 16 March 2005 Convention Center -- Hall D, Poster
Division of Organic Chemistry |
