A series of cyanide-bridged mixed-valence compounds of the form {[dmbRe(I)(CO)(3)](n)-Fe-III(CN)(6)}(3-n) were synthesized, and their MM'CT absorptions were modeled using Marcus-Hush theory. The hypsochromic shift of the MM'CT bands with increasing it is due to the increase in the redox potential of the Fe(III) center as more Re(I) species are bridged to it. The single-crystal X-ray structure of the 3:1 (Re/Fe) species was also determined, and a solvent dependence was performed.