Molecular Motion and Molecular Separations in Cyclophosphazene Clathrates^1,2

The molecular inclusion clathrates formed by tris(o-phenylenedioxy)cyclotriphosphazene (I), tris(2,3-naphthalenedioxy) cyclotriphosphazene (II), and tris(1,8-naphthalenedioxy)cyclotriphosphazene (III) have been examined from the viewpoint of the molecular motions of guest molecules trapped in the tunnel systems. The ease with which one guest molecule can replace another, and the results of competition for the tunnel space by two or more potential guest molecules have also been examined. Mass spectrometry, broadline ¹H NMR, and single-crystal x-ray diffraction techniques were employed. A reexamination of the x-ray structure of I is described.