Characterization of Isolated Ga 2 Molecules by Resonance Raman Spectroscopy and Variations of GaGa Bonding

Isolated Ga 2 dimers were characterized in an argon matrix with the aid of resonance Raman and UV/Vis spectroscopy. The resonance Raman spectra gave evidence of not only the ν(GaGa) fundamental, but also four overtones. Each of the signals exhibits 69 Ga/ 71 Ga isotopic splitting leading to the triplet pattern characteristic of two equivalent Ga atoms. On the basis of the experimental data, a harmonic frequency and anharmonicity constant have been determined for Ga 2 . An estimate of the dissociation energy on the assumption of a Morse‐type potential energy curve results in a D e value (upper limit) of about 145 kJ mol −1 . The force constant (64.8±0.3 N m −1 ) and dissociation energy of Ga 2 are compared with those of other diatomics and those of molecules featuring GaGa bonds.