TY - JOUR

T1 - Determination of the barrier height of a crystalline dipolar molecular rotor directly from temperature-dependent dielectric spectra

AU - Fujimura, Yuichi

AU - Teranishi, Yoshiaki

N1 - Publisher Copyright:
© 2022 The Authors. Journal of the Chinese Chemical Society published by Chemical Society Located in Taipei and Wiley-VCH GmbH.

PY - 2022

Y1 - 2022

N2 - An explicit relation between half-width at half-maximum ΔT in a dissipation factor of dipolar molecular rotors in a solid phase and rotational barrier height Ub was derived within the Debye relaxation model. The formula for Ub is simply expressed as (Formula presented.). Here, T* is the temperature at the peak position in the dissipation factor, and k is the Boltzmann constant. The formula is an alternative to the familiar Arrhenius equation, from which Ub has so far been estimated in various dielectric experiments. The distinction of the proposed formula is the determination of Ub from a single peak in a dissipation factor induced by an electric field, while the Arrhenius equation needs data for the magnitudes of the dissipation factor and temperatures at several peaks. By applying the proposed formula to dipole molecular rotors (ROT-2F) in a single crystalline and polycrystalline, for which Ub values were reported (Horansky et al., Phys. Rev. B 74, 054306 [2006]), the calculated values of Ub were quantitatively reproduced. This indicates the validity of the proposed formula, and the formula is expected to be applied to the analysis of dielectric spectra of 2D dipolar molecular rotor systems.

AB - An explicit relation between half-width at half-maximum ΔT in a dissipation factor of dipolar molecular rotors in a solid phase and rotational barrier height Ub was derived within the Debye relaxation model. The formula for Ub is simply expressed as (Formula presented.). Here, T* is the temperature at the peak position in the dissipation factor, and k is the Boltzmann constant. The formula is an alternative to the familiar Arrhenius equation, from which Ub has so far been estimated in various dielectric experiments. The distinction of the proposed formula is the determination of Ub from a single peak in a dissipation factor induced by an electric field, while the Arrhenius equation needs data for the magnitudes of the dissipation factor and temperatures at several peaks. By applying the proposed formula to dipole molecular rotors (ROT-2F) in a single crystalline and polycrystalline, for which Ub values were reported (Horansky et al., Phys. Rev. B 74, 054306 [2006]), the calculated values of Ub were quantitatively reproduced. This indicates the validity of the proposed formula, and the formula is expected to be applied to the analysis of dielectric spectra of 2D dipolar molecular rotor systems.

KW - dielectric spectroscopy

KW - dissipation factor

KW - molecular dipolar rotor

KW - rotational barrier height

UR - http://www.scopus.com/inward/record.url?scp=85142433124&partnerID=8YFLogxK

U2 - 10.1002/jccs.202200408

DO - 10.1002/jccs.202200408

M3 - Article

AN - SCOPUS:85142433124

SN - 0009-4536

JO - Journal of the Chinese Chemical Society

JF - Journal of the Chinese Chemical Society

ER -