Electronic states and molecular dynamics of single-component molecular conductors [M(tmdt)$_2$] (M=Ni, Pt) studied by $^{13}$C and $^1$H NMR

TL;DR

This study uses $^{13}$C and $^1$H NMR to investigate the electronic states and molecular dynamics of single-component molecular conductors [M(tmdt)$_2$] (M=Ni, Pt), revealing metallic behavior and unusual molecular motions.

Contribution

It provides microscopic evidence of metallicity and molecular motions in [M(tmdt)$_2$] conductors using NMR techniques, highlighting electron correlations and low-energy excitations.

Findings

Evidence of metallic nature from NMR shift and relaxation rates

Anomalous frequency-dependent enhancement in $^1$H relaxation rates

Presence of low-energy molecular motions

Abstract

The molecular conductors [M(tmdt)$_2$] (M=Ni, Pt) consisting of single molecular species are investigated with $^{13}$C NMR and $^1$H NMR. The temperature dependences of $^{13}$C NMR shift and relaxation rate provide microscopic evidences for the metallic nature with appreciable electron correlations. Both compounds exhibit an anomalous frequency-dependent enhancement in $^1$H nuclear spin-lattice relaxation rate in a wide temperature range. These observations signify the presence of extraordinary molecular motions with low energy excitations.