Achieving direct optimal optical controlled initiation in condensed phase systems entails utilizing specific time dependent electric fields to guide the energy flow along the desired reaction coordinate pathway. A preliminary step toward understanding and controlling energetic materials is deciphering the photochemical dynamics that transpire when time dependent electric fields interact with the energetic materials. To illuminate the path towards controlled energetic material photodecomposition we have investigated the π~* ← n excitation of nitromethane and perdeuterated nitromethane with recently developed simultaneous transient absorption and excited state femtosecond stimulated Raman spectroscopy techniques. The ability to simultaneously measure the dynamic absorption and vibrational response due to photoexcitation has elucidated the electric field interaction and associated photochemical dynamics in nitromethane. Our experiments suggest nitromethane shows fast (≤ 1 picosecond) product formation, possibly of methyl nitrite, after excitation with a 266 nm ~150fs pulse.
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