A new polymer-like octathiophene. Synthesis and properties of 4,3'',4''''',4'''''''-tetrabromo-4',4''',3'''',3''''''-tetra(octylsulfanyl)-2,2':5',2'':5'',2''':5''', 2'''':5'''',2''''':5''''', 2'''''':5'''''',2''''''' -octathiophene