Spinning Molecules, Spinning Spins: Modulation of an Electron Spin Exchange Interaction in a Highly Anisotropic Hyperfine Field.

ABSTRACT: An investigation of spin and conformational dynamics in a series of symmetric Cu-Cu porphyrin dimer solutions is presented using electron paramagnetic resonance (EPR) spectroscopy. Previous spectral simulations focused on the isotropic exchange interaction (J _avg) between the Cu centers. In this work, an additional line broadening parameter (J _mod) is explored in detail via variable temperature X-band EPR in liquid solution for several different structures. The J _mod phenomenon is due to fluctuations in the spin exchange interaction caused by conformational motion of the porphyrin planes. The J _mod parameter scales with the inverse of the rotational barriers that determine the Boltzmann-weighted torsional angle distrib

SUBMITTER: Brugh AM 

PROVIDER: S-EPMC8552362 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature