Multiphoton Ionization of Ammonia Clusters with a Tunable Laser
Clusters of ammonia, formed by adiabatic expansion, were subjected to analysis in a time‐of‐flight mass spectrometer following multiphoton ionization. All cluster ions had the composition (NH3)n · H+ (with n ranging up to approximately 65) and none corresponding to (NH3)n·+ were detected with the exception of n = 1. An unusually stable species (NH4+)(NH3)4 was produced under all expansion and ionizing conditions investigated; it is attributed to an especially stable ion structure. Well resolved rotational structure for the β and c̄ states of a cold monomer beam were obtained and rotational assignments are presented for the c̄' band. A search for resonances in the ammonia clusters failed to reveal any well resolved structure, although isotope shifts in the monomer spectra were found through use of deuterium substitution.
Berichte der Bunsengesellschaft für physikalische Chemie
Digital Object Identifier (DOI)
O. Echt, S. Morgan, P. D. Dao, R. J. Stanley and A. W. Castleman, Jr., Multiphoton Ionization of Ammonia Clusters with a Tunable Laser, Ber. Bunsenges. Phys. Chem. 88 (1984) 217