Zero Electron Kinetic Energy Spectroscopy and Theoretical Calculations of InNH3

InNH3 has been studied with single-photon zero electron kinetic energy (ZEKE) spectroscopy and density functional theory and ab initio calculations. The ZEKE spectrum reveals vibrational structures of the cation and neutral complexes. The comparison of the experiment and theory establishes that the indium-ammonia complex is a simple adduct. The adduct has a C 3 v 1A1 ground state in the ion and a C s 2A‘ ground state in the neutral. The lower symmetry of the neutral molecule arises from a Jahn−Teller distortion. The ionization energy of the 2A‘ state is 39 689(3) cm-1. The indium−ammonia stretch frequency is 234 cm-1 in the 1A1 state and 141 cm-1 in the 2A‘ state. The stronger metal−ligand bonding in the ion state is attributed to the additional charge−dipole and covalent interactions.