2,3,5-Tri­chloro-6-(2-diethyl­amino­vinyl)-1,4-benzo­quinone

We report the structure of the title compound, C₁₂H₁₂Cl₃NO₂, which belongs to a group of compounds called blue quinones. It is a remarkable near-IR dye with interest for non-linear optics. It crystallized in monoclinic space group P2₁/a with one mol­ecule in the asymmetric unit. The molecular structure is approximately planar and exhibits little bond-length alternation, indicating a high degree of charge-transfer from the amine lone pair to the quinone.