Electronic Structure of Re(2)(O(2)CR)(4)Cl(2) Complexes (R = H, CMe(3)) and Reassignment of the Electronic Absorption Spectrum of Re(2)(O(2)CCMe(3))(4)Cl(2).

Electronic structure calculations on two dinuclear rhenium(III) carboxylate complexes, Re(2)(O(2)CH)(4)Cl(2) and Re(2)(O(2)CCMe(3))(4)Cl(2), are presented and discussed. Allowed electronic transitions for both molecules were calculated using time-dependent density functional theory (TDDFT). The results for the pivalate dimer, Re(2)(O(2)CCMe(3))(4)Cl(2), are compared with previously reported single-crystal polarized absorption spectra obtained by Martin and co-workers (Inorg. Chem.1984, 23, 699-701). Several revisions to the previous spectral assignments are proposed.