Novel nanotube-coordinated platinum complexes

Pt-doped (5,5) single-walled carbon nanotubes have been studied within density functional theory using a model system consisting of a single Pt center in a symmetrical nanotube segment with capping H atoms. The geometric and electronic properties of this hypothetical material have been investigated. Our calculations suggest a strong affinity of the Pt atom localized within the supramolecular nanotube framework for carbon monoxide. This proposed adsorption process takes place exothermically and yields a new type of nanotube-coordinated organometallic complex similar to classical alkylplatinurn species bearing the CO ligand. In this case, however, three coordination sites of the Pt locus are essentially fixed by the backbone of the carbon nanotube and disconnection is unlikely. Metal doping of pure single-walled carbon nanotubes and subsequent adsorption of small molecules may lead to facile control of the fundamental characteristics of these materials. Unprecedented chemical reactivities may also be achieved through a novel possible mechanism coupling elements of surface catalysis with transition-metal mediated transformations.