The gallium complexes were produced in pulsed molecular beams and studied with zero electron kinetic energy (ZEKE) photoelectron spectroscopy. Intermolecular vibrational frequencies and adiabatic ionization potentials (IPs) were obtained from ZEKE spectra. Ground electronic states were identified by combining the ZEKE spectra with quantum chemical and Franck-Condon calculations. Ga-NH3 has an IP of 40 135 cm(-1) and metal-ligand stretching frequencies of 270 cm(-1) (omega (+)(s)) in the ion and 161 cm(-1) (nu (s)) in the neutral. The IP of Ga-NH2CH3 is 39 330 cm(-1), and the vibrational frequencies are 93 cm(-1) (nu (b)) for the Ga-N-C bending, 124 cm(-1) (omega (+)(b)) for the Ga+-N-C bending, and 299 cm(-1) (omega (+)(s)) for the Ga+-N stretching. The strength of the gallium-methylamine binding is stronger than that of the gallium-ammonia. The ground state of Ga-NH3 is (2)A(')(C-s) and that of Ga+-NH3 is (1)A(1)(C-3v). In contrast, Ga-NH2CH3 has two doublets, (2)A(') and (2)A(')(C-s), with virtually the same energies, whereas Ga+-NH2CH3 has a (1)A(')(C-s) ground state.