Stacking interaction of cytosine with carbon nanotubes: MP2, DFT and Raman spectroscopy study

We employed the Raman spectroscopy and the MP2 and DFT (with the MPWB1K, M05, M05-2X and MPW1B95 functionals) calculations to study the interaction of cytosine with SWCNTs (single-wall carbon nanotubes). The Raman spectra of SWCNT and SWCNT-cytosine films showed that the non-covalent interaction results in a down-shift of the frequency of the most intensive band of the SWCNT at 1590 cm−1 (the G-mode). The interaction energy in the complex formed by cytosine with a fragment of the zigzag(10, 0) SWCNT calculated at the MP2/6-311++G(2d,p) level of theory is −62.4 kJ/mol.