Preparation and characterization of a new inclusion compound with a 1D molecular arrangement of organic radicals using a one-dimensional organic homogeneous nanochannel template

Abstract

A new inclusion compound with a one-dimensional molecular arrangement of organic radicals (2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)) was prepared using the template compound of tris(o-phenylenedioxy)cyclotriphosphazene (TPP) by the following two methods: i) adsorption of TEMPO vapor under vacuum at 313 K and ii) slow recrystallization in mesitylene. The arrangement of TEMPO molecules in the TPP 1D nanochannel was confirmed by thermogravimetric analysis (TG), powder XRD and ESR measurements. TEMPO molecules were accommodated in the TPP nanochannel with no decomposition, and were arranged with the orientation of the nitroxide group in the TEMPO molecule perpendicular to the axis of the nanochannel. The TPP/TEMPO inclusion compound can include TEMPO molecules up to one molecule per unit cell in the TPP crystal lattice.