In 1935, this compound was refined and correctly described as thiamine.

This compound was first described by Edmund Hess in 1876.

The compound was described in 1997 as a transient species in mass spectrometry experiments.

The compound is usually described as a combination of two resonance structures:

This compound was first described in the 1930s.

These compounds were first described by John Wallace and colleagues.

The compound was first described by Bähr and Schleitzer 1958.

These compounds were first described by Charles R. Hauser in 1947.

To date, no clinically viable compounds targeting these enzymes have been described.

Many other compounds with quadruple bonds have been described, often by Cotton and his coworkers.