The photoionization and photodissociative ionization processes of p-nitrotoluene(C,H,NO,) have been studied using the photoionization mass spectrometry wlth synchrotronradiation(SR) as the light source- The ionization potential (PI) of p-nitrotoluene and eightappearance potentials(P.) of the ionic fragment from the SR photodissociative ionization ofC:H:NO, have been measured. Based on the mass spectra of C,H:NO, obtained with SR pho-tolonization and the relationship of energy in the processes, the most possible channels ofphotodissociative ionization of p-nltrotoluene have been analyzed.
In this paper,we report the photoionization and photodissociative ionization processes of azobenzene(PHAB) using vacuum ultraviolet synchrotron radiation(SR) photoionization mass spectroscopy.The ionization potential(IP) of the PHAB molecular and the apparant potential(AP) of the main ionic fragments from the SR photodissociative ionization of PHAB have been measured.On the basis of IP(C 12 H 10 N 2O) and AP measured in this experiment,dissociative energy D 0(OHC 6H 4N 2-C 6H 5),D 0(OHC 6H 4N 2-C 6H + 5),D 0(OHC 6H 4N + 2-C 6H 5),D 0(OHC 6H 4-N 2C 6H 5),D 0(OHC 6H 4-N 2C 6H + 5) and IP(C 6H 4N 2O) have been evaluated.Based on the results of the mass spectroscopy of PHAB,possible channel of the photodissociative ionization of PHAB was analyzed.
The photodissociation of NO＋ at c3∏（v′=0） state is studied by threshold photoelectron- photoion coincidence imaging method. By some assumptions, the relations between velocity in center of mass （CM） coordinates and most probable center of mass （MPCM） coordinates, time of flight and displacement in the velocity map image of fragment ions are derived using vector addition of velocity and displacement on the condition of perpendicular molecular beam. Using these relations the velocity in CM coordinates, the velocity and angular distri- bution of N＋ fragment ions in MPCM coordinates are obtained and discussed, respectively.
