The Electronic Spectrum of Re2Cl82-: A Theoretical Study

One of the prototype compounds for metal-metal multiple bonding, the Re2CI ion, has been studied theoretically using multiconfigurational quantum chemical methods. The molecular structure of the ground state has been determined. It is shown that the effective bond order of the Re-Re bond is close to three, due to the weakness of, in particular, the 6 bond. The electronic spectrum has been calculated with the inclusion of spin-orbit coupling. Observed spectral features have been reproduced with good accuracy, and a number of new assignments are suggested.