the interaction between dopamine and carbon nanotube: a dft and nbo approach

the density functional theory (dft) and the natural bond orbital (nbo) calculations basedmethod b3lyp/6-31g were carried out to study the interaction of dopamine with carbon nanotube.the nanotube used in this study, includes 60 c atoms (6, 6) type. relative and formation energies ofcompounds, muliken charges, occupancy, the highest occupied molecular orbital (homo) and thelowest unoccupied molecular orbital (lumo), the homo-lumo band gap and the electronicchemical potential (μ) were calculated. the nbo analysis showed there is a hyperconjugativeinteraction between oxygen and nitrogen lone — pair electrons of dopamine and a' or i orbitals ofcarbon atom of nanotube. results indicated that the composite between nanotubes and the ncentereddopamine is more stable than 01 - centered dopamine and both of them are stable than thesingle agent.