Red and yellow color aspects of compound 3-dicyclopropylmethylene-5-dicyanomethylene-4-diphenylmethylenetetrahydrofuran-2-one: Chromism effect

The title compound exists as yellow (1Y) and red (1R) crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in 1Y are very weak. By the mechanical crushing as well as in solution 1Y again becomes red due to the absence of intermolecular interactions. We explain this color behavior by crystallochromism and solvation chromism.

Very weak intermolecular interactions exist between the CN parts of the 1Y crystal (yellow), but by the mechanical crushing 1Y becomes red (1R) with the absence of intermolecular interactions. 1Y and 1R gave red solution revealing that no intermolecular interaction of 1Y exists in solution.Figure optionsDownload as PowerPoint slide