Atropisomerism as a probe of restrictions to motion above and below the glass transition temperature of polymers

This short review and interpretation of work conducted in the authors' laboratory concerns the use of atropisomeric 1, 1'-binaphthyl derivatives to gain information about the glassy properties of polymers. Bridged binaphthyls appended with oligophenyl paddles are found to yield a series of probes whose racemization kinetics reveal new kinds of information concerning the basis of the time scale and length scale for the restrictions to motion and the heterogeneity of the polymeric glassy state. Because the time scale of the racemization is slower than all other glass probes used previously, new kinds of information were gained for the first time below the glass transition temperature. (C) 2002 Wiley-Liss, Inc.