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Updated: Jun 25, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Molecular "compasses" and "gyroscopes". I. Expedient synthesis and solid state dynamics of an open rotor with a
Zaira Dominguez1, Hung Dang, M Jane Strouse
1Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.
Abstract:
We describe our efforts toward the preparation of materials built with molecules possessing topologies analogous to those of macroscopic compasses and gyroscopes. Samples of 1,4-bis(3,3,3-triphenylpropynyl)benzene (3) were prepared by a simple two-step procedure from triphenylmethyl chloride (1) and 1,4-diiodobenzene. The structure of compound 3 is such that the central phenylene can play the role of a gyroscope wheel while the two tritylpropynyl groups can act as an axle and shielding framework. Crystals of a benzene clathrate were characterized by single crystal X-ray diffraction and variable-temperature solid state NMR while their thermal stability was determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The rotational dynamics of the phenylene group in the benzene clathrate and in desolvated samples were characterized in terms of a two-fold flipping process. Solid state rotational barriers of ca. 12.8 and 14.6 kcal/mol were estimated for the benzene clathrate and desolvated samples, respectively.
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