Angle-selection experiments of a spin soliton in randomly oriented ladder polydiacetylene were carried out by pulsed electron paramagnetic resonance (EPR) at W-band. EPR measurement using 94 GHz microwaves increased the difference in the resonance field due to g anisotropy of the spin soliton to allow the orientation dependence of transient nutation, electron nuclear double resonance (ENDOR) and spin relaxations to be investigated. The shape of the g anisotropy-resolved nutation spectrum was discussed on the basis of the EPR transition moments and the differences between spin relaxation times. Reliable assignments of hyperfine couplings to the β protons (Hβ) of the alkyl side chains were achieved with the support of W-band ENDOR measurements. No significant orientational dependence in the T1 and T2 processes was found in terms of isotropy of the Hβ-hyperfine interaction.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics