Although the thus obtained tautomer 8 is centrosymmetric, and in theory, its fundamental electronic excitation would be no different from that in 1 with only eight  electrons in its conjugated system; however, in practice, it is unclear as to what extent this tautomerisation does take place in solid phase for dimer 7; moreover, both 7 and its tautomer 8 possess more auxochromic oxygens in their conjugated systems than that of 1, which should not be overlooked. Thus, even though the above complications do add a certain element of confusion when we come to consider the fundamental electronic excitation for this type of conjugated nitrofuranyl species, but what matters is that the combined conjugative effect of 7 together with its more stable tautomer 8 in solid phase gives its crystal lattice an intrinsic coral pink colour (Fig. ); otherwise, the pertinent dimer itself similar but different to 1 would only exhibit a dark orangish colour, and that this should be so is a corollary of its centrosymmetric nature.