Raman and SERS investigation of isolated sp carbon chains

Carbon chains with sp hybridization and a known distribution of lengths have been studied by Raman and Surface Enhanced Raman Scattering (SERS). With the support of density functional theory simulations the observed Raman features have been assigned to active modes of individual chains. SERS spectra show remarkable differences, attributed to the interaction between sp chains and Ag nanoparticles used as a SERS active medium. The results obtained for this model system permit in principle to explain a large number of Raman data from molecular and solid sp/sp2 carbon systems.