It is a black crystalline solid which is thermally stable up to 400 °C. When doped with alkali metals conductor and superconductor properties are achieved. It is very difficult to oxidize and easy to reduce by six reversible stepwise reductions. It is only sparingly soluble in organic apolar solvents such as CS2, benzene, toluene and CH2Cl2. With broad UV-vis absorption, long lived triplet excited state with high absorption coefficient is got. It is an acceptors of electrons and electronic energy, photostable, a potent singlet oxygen sensitizers and has fluorescence.