Using a Nd:YAG pumped pulsed dye laser-wavelength extender as UV light source, the multiphoton ionization of o CS was studied in a supersonic moecular beam with a Time of Flight mass spectrometer and a Magnetic Bottle Time of Flight photoelectron spectrometer. The intermediate resonant states of OCS were obtained from the massselected MPI spectra by scanning the laser wavelength. From 2+1 MPI photoelectron spectra at dmerent resonant wavelength the vibrational levels of OCS+ ion in electronic ground state X2 H3/2,1/2 were assigned and their X2II spin-orbital splitting was determined to be 0.046eV. The non Franck-Condon behavior between the Rydberg intermediate state and the ionic state has been discussed.
The 6H-pyridine clusters have been studied by the TOF mass spectrometry,the VUV from synchrotron rediation and the molecular beam technique three-type clusters are observed in the VUV photoionization mass spectroscopy: Pn+(n=2-5,P stands for6H-pyridine molecule), PnH+ (n=2-4) and Pn (H2O)m+(n=4,5, m=1;n=6, m=1,2). ThePnH+ clusters may have the chain structure,the Pn+ and Pn(H2O)m+ clusters may havethe cyclic structures, all of these are formed by the hydrogen-bond.
