Knowledge Bank

The electronic spectra of a variety of carbon chanis, $Cn,CnH,HCnH$ and their ions $Cn-,HCnH+$ have been identified in neon matrices between 200 and 2500nm. This has been achieved by mass-selected codeposition of ions with excess of neon to form a matrix at 5 K. The understanding of the electronic transitions of the carbon chains point out which type and sizes are relevant for astrophysical consideration, such as in relation to the diffuse interstellar bands. Infrared bands of some such mass-selected carbon species are also detectable. The technique has also been used to elucidate the formation of carbon chains in argon and neon matrices by diffusive coagulation on annealing.