Chemical Physics Letters, Vol.501, No.4-6, 369-374, 2011
Vibrational spectroscopy of nitroaromatic self-assembled monolayers under extreme conditions
Vibrational spectra up to 8 GPa and 600 degrees C were obtained for self-assembled monolayers (SAMs) on noble metal surfaces of the energetic material simulant 4-nitrobenzenethiol (NBT). The high-pressure measurements used a surface-enhanced Raman sensor. The high-temperature measurements used femtosecond laser flash-heating and nonlinear coherent vibrational spectroscopy. The SAM nitro stretching transition v(NO2)(s) is insensitive to flash-heating where there is no time for chemical reactivity or thermal expansion. A large pressure broadening in v(NO2)(s) of the SAM but not in solid NBT was associated with surface adlayer rearrangement. The implications for time-resolved measurements of shock-compressed energetic materials are discussed. (C) 2010 Elsevier B.V. All rights reserved.