title: ESR study of the molecular orientation and dynamics of stable organic radicals included in the 1-D organic nanochannels of 2,4,6-tris-4-(chlorophenoxy)-1,3,5-triazine.
abstract: The molecular orientation and dynamics of the organic stable radicals such as 2,2,6,6-tetramethyl-1-piperidinyl-1-oxyl (TEMPO) or 4-hydroxy-TEMPO (TEMPOL) included in the one-dimensional (1-D) organic nanochannels of 2,4,6-tris-4-(chlorophenoxy)-1,3,5-triazine (CLPOT) were investigated by examining the inclusion compounds (ICs) diluted by the co-inclusion of non-radicals using ESR spectroscopy. Spectral simulation showed that the axial rotation of TEMPO or TEMPOL molecules is excited in the nanochannels with activation energies of 8 and 7 kJ mol(-1) , respectively. The rotation axis was estimated to be tilted towards the principal x direction in the axis system of the g-tensor of the respective radicals. This is quite different from that for similar ICs in the nanochannels of tris(o-phenylenedioxy)cyclotriphosphazene (TPP), in which the radicals are axially rotating around the principal axis y of the g-tensor. The difference is attributed to the larger nanospace of the CLPOT nanochannels.
authors.affiliation: Department of Chemisty, College of Humanities and Sciences, Nihon University, 3-25-40, Sakura-jo-sui, Tokyo, 156-8550, Japan. hirawk@chs.nihon-u.ac.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Asaji
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tani
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*
chemical_list: C575377:2,4,6-tris-4-(chlorophenoxy)-1,3,5-triazine; D005609:Free Radicals; D014227:Triazines