Spectroscopy, structure, and energy transfer of transient radicals in combustion

Hai-Lung Dai

关键词: COMBUSTION KINETICS;    EMISSION SPECTRA;    INFRARED SPECTRA;    ENERGY TRANSFER;    EXCITATION;    PHOTOLYSIS;    RADICALS;    MORPHOLOGY combustion;    radicals;    time-resolved spectroscopy;    2-dimensional spectroscopy;   

DOI  :  10.2172/908543
RP-ID  :  DOE/ER/13584
PID  :  OSTI ID: 908543
Others  :  TRN: US200821%%249

学科分类：化学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

Spectroscopy, structure, and energy transfer of transient radicals in combustion Period: 4/15/04-12/31/06 PI: Hai-Lung Dai, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104 [e-mail] A newly developed approach based on nanosecond time resolved Fourier Transform IR Emission Spectroscopy (TR-FTIRES) has been applied to the investigation of the spectroscopy and structure of unknown transient radicals that are important in combustion processes. Several radicals including deuterated-vinyl, cyanooxomethyl (OCCN) and ketenyl (HCCO) whose vibrational structure has not been determined have been examined. The transient radical species is produced with high vibrational excitation through UV photolysis of a precursor molecule. The IR emission from the highly excited species through its IR active vibrational modes is detected with fast time resolution using the TR-FTIR technique. A new two-dimensional cross-spectra correlation technique has been developed for analyzing the time-resolved FTIR emission spectra. This analysis reveals the common set of emission bands from the same target radical in the emission spectra obtained using different precursors. The spectroscopic approach also allows the reactions of the excited radical and the photolysis reaction of the precursor molecules to be characterized. All these information are fundamentally important to the understanding of chemical dynamics of radicals as well as the combustion processes.