The vibrational Raman spectra of a decathiophene are provided in three relevant oxidations states: for the radical cation, its class III mixed valence system and its "frozen, -170 degrees C" class II MV analogue; for the dication, its singlet biradical pi-dimer and its "hot, +70 degrees C" magnetically active triplet excited state. Everything is compatible with interpentathiophene charge delocalization occurring at distances of 4-5 A similar to those found in the crystals of pi-stacked oligothiophenes. This stresses the interest of this spectroscopic tool for the analyses of electronic processes in crystals or in thin films of conjugated organic molecules.