The new compounds Me2NH, GaH3 and Me2PH, GaH3 have been synthesised and their physical and chemical properties investigated. Gas-phase displacement reactions have shown that the order of donor power towards gallium hydride for the various ligands employed lies in the order Me2NH> Me3N∼ Me3P> Me2PH. Intramolecular hydrogen elimination from these compounds yields Me2NGaH2 and Me2PGaH2 respectively, and ...