Intramolecular electron transfer in the mixed-valence [Co(3,5-DTBCat)(3,5-DTBSQ)(bpy)] complex: Beyond valence tautomerism

The series of complexes [Co(Q)(2)(bpy)](n) (n = -1, 0, +1) that can be derived by partial reduction or oxidation of complex 1, ls-Co(III) has been synthesized and studied. The results support the theoretical calculations which pointed to an intervalence transfer (IT) from the Cat(2) to the SQ ligand rather than a LMCT transition as the origin for the low-energy band transition centered at 2500 nm observed for 1, ls-Co(III). (c) 2008 Elsevier B. V. All rights reserved.