Quantum Computations of Interactions of Most Reactive Tricyclic Antidepressant Drug with Carbon Nanotube, Serotonin and Norepinephrin

First principles calculations were performed to study the neurotransmitters, tricyclic antidepressant drugs and (5,5) carbon nanotube in the gas phase and solution media for comparison purposes. All calculations were performed using DMol3 code in materials studio 5.5. The simulation results revealed that, the nitroxazepine is quite a reactive drug, so that it can act as the electron donating specie in its interacting with carbon nanotube. In addition, the nitroxazepine is the electron acceptor and serotonin and norepinephrine is the electron donor. To explain the interaction of the carbon nanotube, serotonin, and norepinephrine with nitroxazepine, their local reactivity was analyzed through Fukui functions. The results show that the hydrogen bonding between oxygen atoms of the nitroxazepine and OH of the serotonin and norepinephrine has been assigned as the dominant interaction. In order to gain a deeper understanding of the interaction between the nitroxazepine with the carbon nanotube, serotonin and norepinephrine, calculations of binding energies, quantum molecular descriptors, the most important modes of the vibrational frequencies and density of states (DOS) have been carried out.