Carbon linear structures with sp hybridization are interesting systems for fundamental aspects related to the science of carbon clusters [1] and nanotubes [2]. The formation of sp carbon chains is expected in the initial stage of small carbon cluster formation, on the road towards the fullerene structure, when the sp2 phase is energetically less favorable [3,4]. Linear carbon chains with sp hybridization characterized by a known distribution of lengths have been studied by Raman and Surface Enhanced Raman Scattering (SERS) spectroscopy. With the theoretical support of Density Functional Theory (DFT) simulations, the observed Raman features have been assigned to the active modes of isolated chains with polyynic structure. Interestingly, the SERS spectra show remarkable differences with respect to the Raman spectra. In particular we observed a shift of the peaks and the appearance of a new peak in the SERS. With the help of first principles calculations we have assigned these changes to the interaction between sp chains and the silver nanoparticles used as a SERS active medium. The results obtained for this model system permit in principle to explain a large number of experimental Raman data from isolated molecules/clusters and solid sp/sp2 carbon systems. References [1] A. Van Orden, Chem. Rev. 98, 2313 (1998). [2] Y. Liu et al., Phys. Rev. B 68, 125413 (2003). [3] R.J. Lagow et al., Science 267, 362 (1995). [4] P.R. Kent et al., Phys. Rev. B 62 15394 (2000).
SERS investigation of polyynes produced with the submerged arc discharge method
TOMMASINI, MATTEO MARIA SAVERIO;LUCOTTI, ANDREA;FAZZI, DANIELE;DEL ZOPPO, MIRELLA ELVIRA ANGELA;CASTIGLIONI, CHIARA;ZERBI, GIUSEPPE;CASARI, CARLO SPARTACO;LI BASSI, ANDREA;RUSSO, VALERIA;BOTTANI, CARLO ENRICO;
2005-01-01
Abstract
Carbon linear structures with sp hybridization are interesting systems for fundamental aspects related to the science of carbon clusters [1] and nanotubes [2]. The formation of sp carbon chains is expected in the initial stage of small carbon cluster formation, on the road towards the fullerene structure, when the sp2 phase is energetically less favorable [3,4]. Linear carbon chains with sp hybridization characterized by a known distribution of lengths have been studied by Raman and Surface Enhanced Raman Scattering (SERS) spectroscopy. With the theoretical support of Density Functional Theory (DFT) simulations, the observed Raman features have been assigned to the active modes of isolated chains with polyynic structure. Interestingly, the SERS spectra show remarkable differences with respect to the Raman spectra. In particular we observed a shift of the peaks and the appearance of a new peak in the SERS. With the help of first principles calculations we have assigned these changes to the interaction between sp chains and the silver nanoparticles used as a SERS active medium. The results obtained for this model system permit in principle to explain a large number of experimental Raman data from isolated molecules/clusters and solid sp/sp2 carbon systems. References [1] A. Van Orden, Chem. Rev. 98, 2313 (1998). [2] Y. Liu et al., Phys. Rev. B 68, 125413 (2003). [3] R.J. Lagow et al., Science 267, 362 (1995). [4] P.R. Kent et al., Phys. Rev. B 62 15394 (2000).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
