Time scale of electronic and molecular motions in the conducting radical cation salt diperylene hexafluorophosphate

Temperature dependence of intra-stack defect spin–conduction-electron spin interaction in fluoranthene and perylene radical cation salts

“…The librational motion of the stacked arene molecules (possibly enlarged at the localized defect sites), which freezes in on approaching the Peierls transition, gives a reasonable explanation for the temperature dependence of J DC . Together with the above-mentioned NMR measurements of the longitudinal relaxation rate of the arene protons and the counter-ion 19 F nuclei [11,12], these results indicate the following conclusions. For the locking-in of a Peierls distortion of the crystal lattice, a coupling of the CDWs in neighbouring stacks is a necessary precondition [13].…”

“…This scenario is supported by temperature-dependent NMR measurements of the longitudinal relaxation rates of the 19 F nuclei of the counter-ions and the protons of the arene molecules [11,12]. These measurements showed that the octahedral complex anions in the arene salts exhibit fast re-orientational jumps at room temperature, which freeze-in on cooling down and approaching the Peierls transition.…”

Determination of all relevant conduction electron scattering times in an exceptionally anisotropic arene conductor, the 12:7 pyrene hexafluoroantimonate radical cation salt

“…The analysis of the temperature and frequency dependence of the nuclear spin-lattice relaxation is an established method for the monitoring of molecular reorientation [16][17][18] and electron spin dynamics [3,16,17,19,20] in radical cation salts of arenes with complex anions. We refer the reader to these references for the relations describing the influence of SbF 6 reorientations on 19 F nuclear spin relaxation.…”

“…We refer the reader to these references for the relations describing the influence of SbF 6 reorientations on 19 F nuclear spin relaxation. For protons, the influence of 19 F-1 H magnetic dipolar interaction, modulated by SbF 6 reorientation jumps, and of 1 H-1 H interaction, modulated by PY librational and vibrational motion, on the spin-lattice relaxation rate can be parametrized as [16,17,21]…”

“…For the conduction electron (modified Korringa) contribution to the proton spin-lattice relaxation, a decomposition into frequency dependent and independent parts [3,17,19,20]:…”