Towards bulk behaviour of long hydrogenated carbon chains?

Abstract

The dipole forbidden A ¹Δ_u(¹Σ⁻_u) ← X ¹Σ⁺_g transitions of the linear carbon chains HC_2nH (n = 3–7) were observed in the gas phase under supersonic molecular beam conditions. The absorption position was found to form a progression to lower energy with respect to chain length. This is discussed in relation to the electronic structure of long HC_2nH carbon chains (n < 14) and their trend towards bulk behaviour. It is determined that chains as long as 3 nm (e.g. HC₂₆H) are still far from exhibiting the properties of a one-dimensional crystal.