ORGN 412 |
| A series of fluorescent chemosensors to detect the high explosives RDX and PETN based on a photochemical reduction reaction are presented. 10-methyl-9,10-dihydroacridine (AcrH2) was found to transfer a hydride ion equivalent to either RDX or PETN upon irradiation at 313 nm in degassed acetonitrile solutions. Mechanistic photophysical studies indicate that the photoreduction of RDX proceeds via a two-step electron-hydrogen atom transfer reaction, whereas PETN photoreduction proceeds via a three-step electron-proton-electron transfer sequence. Additionally, dihydroacenes, such as 9,10-dihydroanthracenes, xanthenes and 9-fluorenols were also shown to analogously participate in the photoreduction of RDX or PETN. A [bis(9,10-dihydroacridinyl)-N,N,N',N'-tetramethylethylenediamine] zinc(II) complex selectively displays an 80- and 25-fold increase in 480 nm emission intensity upon reaction with RDX and PETN, respectively, while being photostable under ambient conditions, thus making it the first chemosensor to display a direct fluorescent response to either RDX or PETN. |
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Materials, Devices, and Switches
8:00 AM-12:00 PM, Tuesday, August 21, 2007 BCEC -- 258A, Oral
Division of Organic Chemistry |