The distinguishing of cis-trans isomers enabled via dielectric/ferroelectric signal feedback in a supramolecular Cu(1,10-phenanthroline)(2)SeO4 center dot(diol) system

摘要

Ferroelectric polarization is sensitive to external stimuli, such as temperature or pressure, the variation of which can induce a slight change in crystal structure. Similarly, for ferroelectric crystals in host-guest systems, the inclusion of different guest molecules can affect the crystal packing a small amount; however, it may alter the ferroelectric properties significantly. In this report, we discovered that the supramolecular host-guest system Cu(1,10-phen)(2)SeO4 center dot(diol) (phen is the abbreviation of phenanthroline) can distinguish cis-trans isomers via physical signal feedback, i.e. dielectric/ferroelectric responses. The supramolecular crystal is nonferroelectric and shows inconspicuous dielectric behavior when trans-1,2-cyclohexanediol is included, while a ferroelectric system is achieved when the host interacts with cis-1,2-cyclohexanediol. Moreover, the ferroelectric-paraelectric phase transition involved in cis-1,2-cyclohexanediol occurs together with an interesting chair-boat conformation change, as well as an order-disorder transition. As far as we know, this is the first discovery showing that dielectric/ferroelectric signal responses can be used to distinguish cis-trans isomers in the field of ferroelectric materials. This finding enriches studies of the molecular ferroelectric family and might provide inspiration for smart device design.