@article {2677, title = {Chemistry of Single-Walled Carbon Nanotubes}, journal = {J. Comput. Theor. Nanosci.}, volume = {6}, number = {6}, year = {2009}, note = {ISI Document Delivery No.: 441BUTimes Cited: 0Cited Reference Count: 146Yeung, Charles See Tian, Wei Quart Liu, Lei Vincent Wang, Yan AlexanderSp. Iss. SI}, month = {Jun}, pages = {1213-1235}, type = {Review}, abstract = {
Single-walled carbon nanotubes (SWCNTs) have received significant attention from the scientific community over the past 15 years. Of particular interest is the potential of these macromolecules for use in molecular electronics, chemical sensory technology, nanobiology, and transition metal catalysis, For effective applications, the selective functionalization of the aforementioned all-carbon framework is necessary but has been met with considerable challenges. Herein, we review our approach to the exploration of structural and electronic properties of SWCNTs within density functional theory (DFT). Our investigations include mechanistic studies on chemical reactions of SWCNTs with defect and exploration of transition metal doped variants and their ability to adsorb small gas molecules.
}, keywords = {AB-INITIO, Defect, DOPED CARBON, ELECTRICAL-CONDUCTIVITY, ELECTROCHEMICALLY DEPOSITED FILMS, Electronic Structure, Gas Adsorption, GAUSSIAN-TYPE BASIS, GENERALIZED GRADIENT APPROXIMATION, LASER-ABLATION, MOLECULAR-ORBITAL METHODS, NANORODS, NITRIC-OXIDE, Nitrogen Monoxide, platinum, SIDEWALL FUNCTIONALIZATION, Single-Walled Carbon Nanotubes}, isbn = {1546-1955}, url = {The Staudinger reactions of substituted phosphanes and azides have been investigated by using density functional theory. Four different initial reaction mechanisms have been found. All systems studied go through a cis-transition state rather than a trans-transition state or a one-step transition state. The one-step pathway of the phosphorus atom attacking the substituted nitrogen atom is always unfavorable energetically. Depending on the substituents on the azide and the phosphane, the reaction mechanism with the lowest initial reaction barrier can be classified into three categories: (1) like the parent reaction, PH3 + N3H, the reaction goes through a cis-transition state, approaches a cis-intermediate, overcomes a PN-bond-shifting transition state, reaches a four-membered ring intermediate, dissociates N-2 by overcoming a small barrier, and results in the final products: N-2 and a phosphazene; (2) once reaching the cis-intermediate, the reaction goes through the N-2-eliminating transition state and produces the final products; (3) the reaction has a concerted initial cis-transition state, in which the phosphorus atom attacks the first and the third nitrogen atoms of the azide simultaneously and reaches an intermediate, and then the reaction goes through similar steps of the first reaction mechanism. In contrast to the previous predictions on the relative stability of the unsubstituted cis-configured phosphazide intermediate and the unsubstituted trans-configured phosphazide intermediate, the total energy of the substituted trans-configured phosphazide intermediate is close to that of the substituted cis-configured phosphazide intermediate. The preference of the initial cis-transition state reaction pathway is thoroughly discussed. The relative stability of the cis- and the trans-intermediates is explored and analyzed with the aid of molecular orbitals. The effects of substituents and solvent effects on the reaction mechanisms of the Staudinger reactions are discussed in detail.
}, keywords = {AB-INITIO, GAS-PHASE, GAUSSIAN-TYPE BASIS, GOLD(I) COMPLEXES, METAL-COMPLEXES, MOLECULAR-ORBITAL METHODS, ORGANIC-MOLECULES, PHOSPHINIMIDE COMPLEXES, TRIAZADIENYL FLUORIDE, X-RAY CRYSTAL}, isbn = {0022-3263}, url = {