title: Polymorphic structures of iodine and their phase transition in confined nanospace.
abstract: Atomic chains and crystal of iodine were successfully generated in a controlled manner inside single-walled carbon nanotubes (SWNTs). The structure is strongly dependent on the diameter of SWNTs; the single, double, and triple helical structures became quite stable when the diameter of SWNTs matches the certain size. More than three chains of iodine are not very stable, and they often crystallize inside the carbon nanotube when the diameter is larger than 1.45 nm. The crystallization or phase transition in a confined nanospace is thus directly observed, and there is indeed a critical size of the hollow nanospace for the stable formation of the atomic chains of iodine.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Lunhui
authors.initials: L
authors.lastname: Guan
authors.forename: Kazu
authors.initials: K
authors.lastname: Suenaga
authors.forename: Zujin
authors.initials: Z
authors.lastname: Shi
authors.forename: Zhennan
authors.initials: Z
authors.lastname: Gu
authors.forename: Sumio
authors.initials: S
authors.lastname: Iijima
mesh_terms: D003460:Crystallization / Q000379:methods*; D007455:Iodine / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D044367:Phase Transition; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D007455:Iodine