Viologen

Viologens are a family of organic compounds with the formula (C5H4NR)2n+(X-)2. They are N-alkyl derivatives of bipyridines. In some viologens, the pyridyl groups are further modified.

The viologen paraquat (R = methyl), is a widely used herbicide. As early as in the 1930s, paraquat was being used as an oxidation-reduction indicator, because it becomes violet on reduction.

Other viologens have been commercialized because they can change color reversibly many times through reduction and oxidation. The name viologen alludes to violet, one color it can exhibit, and the radical cation (C5H4NR)2+ is colored intensely blue.

This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.