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Observation And Identification Of Metastable Excited States In Ultrafast Laser-Ionized Pyridine, David B. Foote, Timothy D. Scarborough, Cornelis J. Uiterwaal
Observation And Identification Of Metastable Excited States In Ultrafast Laser-Ionized Pyridine, David B. Foote, Timothy D. Scarborough, Cornelis J. Uiterwaal
C.J.G.J. Uiterwaal Publications
We report on the fragmentation of ionized pyridine (C5H5N) molecules by focused 50 fs, 800 nm laser pulses. Such ionization produces several metastable ionic states that fragment within the field-free drift region of a reflectron- type time of flight mass spectrometer, with one particular metastable dissociation being the leading fragmentation process. Because the time of flight is no longer dependent in a simple way on the mass of the ion, the metastable decay is manifested as an unfocused peak on the mass spectrum that appears at a time of flight not corresponding to an integer mass. …
Ultrafast Resonance-Enhanced Multiphoton Ionization In The Azabenzenes: Pyridine, Pyridazine, Pyrimidine, And Pyrazine, Timothy D. Scarborough, David B. Foote,, Cornelis J. Uiterwaal
Ultrafast Resonance-Enhanced Multiphoton Ionization In The Azabenzenes: Pyridine, Pyridazine, Pyrimidine, And Pyrazine, Timothy D. Scarborough, David B. Foote,, Cornelis J. Uiterwaal
C.J.G.J. Uiterwaal Publications
We report on the ultrafast photoionization of pyridine, pyridazine, pyrimidine, and pyrazine. These four molecules represent a systematic series of perturbations into the structure of a benzene ring which explores the substitution of a C–H entity with a nitrogen atom, creating a heterocyclic structure. Data are recorded under intense-field, single-molecule conditions. The pulses (50 fs, 800 nm) are focused into the molecular vapor, and ion mass spectra are recorded for intensities of ∼1013 W/cm2 to ∼1015 W/cm2. We measure ion yields in the absence of the focal volume effect without the need for deconvolution of …