Traditionally, pure carbon chains have mostly been studied by combining them in a protected environment on the (internal) surface of other carbon materials, including carbon nanotubes, polyalkynes, and graphene . Alternatively, the polyynes with generic formula of R 1 -(C≡C) n -R 2 were used as a model for carbon chains to predict their properties . Polymers H-(C≡C) n -H, i.e., H-capped carbon chains, are perhaps the simplest and yet most intriguing species of them.