Quantum-Chemical Calculations and IR Spectra of the (F₂)MF₂ Molecules (M = B, Al, Ga, In, Tl) in Solid Matrices: A New Class of Very High Electron Affinity Neutral Molecules

Electron-deficient group 13 metals react with F₂ to give the compounds MF₂ (M = B, Al, Ga, In, Tl), which combine with F₂ to form a new class of very high electron affinity neutral molecules, (F₂)MF₂, in solid argon and neon. These (F₂)MF₂ fluorine metal difluoride molecules were identified through matrix IR spectra containing new antisymmetric and symmetric M−F stretching modes. The assignments were confirmed through close comparisons with frequency calculations using DFT methods, which were calibrated against the MF₃ molecules observed in all of the spectra. Electron affinities calculated at the CCSD(T) level fall between 7.0 and 7.8 eV, which are in the range of the highest known electron affinities.