A polyyne is an organic compound with alternating single and triple bonds, for example buta-1,3-diyne or diacetylene, C₄H₂. An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with the exception of carbides, carbonates, carbon oxides and gases containing carbon. ... Covalently bonded hydrogen and carbon in a molecule of methane. ...

Along with cumulenes, polyynes are distinguished from other organic chains by their rigidity, which makes them promising for molecular nanotechnology. It has been suggested that Molecular engineering be merged into this article or section. ...

As of 2005, polyynes are only found in the lab and in interstellar molecular clouds where hydrogen is scarce. 2005 is a common year starting on Saturday of the Gregorian calendar. ... A Molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecular hydrogen, H2. ...

Cyanopolyynes such as cyanoacetylene, C₃HN, are particularly common in these interstellar clouds. They were first detected around 1970.

Cyanoacetylene is one of the molecules that is known to exist because of the Miller-Urey experiment. This molecule appears in the large glass container, where water is being boiled. The Miller-Urey experiment attempts to recreate the chemical conditions of the primitive Earth in the laboratory, and synthesized some of the building blocks of life. ...