Noncovalent and covalent functionalization of a (5, 0) single-walled carbon nanotube with alanine and alanine radicals

Muthusivarajan Rajarajeswari, Kombiah Iyakutti, Yoshiyuki Kawazoe

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


We have systematically investigated the noncovalent and covalent adsorption of alanine and alanine radicals, respectively, onto a (5, 0) single-walled carbon nanotube using first-principles calculation. It was found that XH···π (X=N, O, C) interactions play a crucial role in the non-ovalent adsorption and that the functional group close to the carbon nanotube exhibits a significant influence on the binding strength. Noncovalent functionalization of the carbon nanotube with alanine enhances the conductivity of the metallic (5, 0) nanotube. In the covalent adsorption of each alanine radical onto a carbon nanotube, the binding energy depends on the adsorption site on CNT and the electronegative atom that binds with the CNT. The strongest complex is formed when the alanine radical interacts with a (5, 0) carbon nanotube through the amine group. In some cases, the covalent interaction of the alanine radical introduces a half-filled band at the Fermi level due to the local sp 3 hybridization, which modifies the conductivity of the tube.

Original languageEnglish
Pages (from-to)771-781
Number of pages11
JournalJournal of Molecular Modeling
Issue number2
Publication statusPublished - 2012 Feb


  • Adsorption
  • Amino acids
  • Carbon nanotubes
  • Density functional theory

ASJC Scopus subject areas

  • Catalysis
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Computational Theory and Mathematics
  • Inorganic Chemistry


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