Qualitatively and quantitatively different solvatochromism of the MLCT and MMCT absorption bands of centrosymmetric acceptor-bridged diiron(II,II) and diiron(III,II) cyanide complexes. Inorganica Chimica Acta, (336):55--60, 2002. [PUMA: absorption charge complex cyano iron mixed solvatochromism transfer valence]