# Supramolecular Ion-Channel Engineering of Spin–Charge Coexistence in a [Ni(dmit)2] Conductor Hosting Mixed-Valence Mn Cations

## TL;DR

This study creates a new material combining ion channels and conductive layers to control spin and charge interactions.

## Contribution

The first system combining transition-metal-ion [18]crown-6 channels with [Ni(dmit)2] layers for tuning spin–charge coexistence.

## Key findings

- The compound exhibits high conductivity at 300 K due to supramolecular channel fluctuations.
- Mn moments are decoupled from the [Ni(dmit)2] sublattice, showing Curie–Weiss behavior.
- The structure enables one-dimensional variable-range hopping and antiferromagnetic chains.

## Abstract

The interplay between electrical conduction and magnetism
offers
a powerful means to elucidate emergent mechanisms and control properties;
however, realizing this in Ni­(dmit)2 crystals has been
challenging due to undesirable reactions among their components. Mn1.83([18]­crown-6)3[Ni­(dmit)2]11(H2O)7.33(CH3CN)2 (1) is prepared in the present study, integrating one-dimensional
[18]­crown-6 ion channels hosting mixed-valence Mn2+/Mn3+ with conducting [Ni­(dmit)2] layers. Subsequently,
a structure-driven mechanism of conductivity is clarified. In the
crystal, [Ni­(dmit)2] forms one-dimensional dimer–dimer–trimer–dimer–dimer
stacks; weak interchain contacts generate two-dimensional sheets alternating
with supramolecular channel layers. Mn ions occupy two partially populated
sites and adopt seven-coordinate environments with two axial aqua
ligands and five equatorial crown-ether oxygen. Magnetometry indicates
Mn moments are effectively decoupled from the conducting [Ni­(dmit)2] sublattice: the Mn sublattice follows Curie–Weiss
behavior with an exceptionally small Weiss temperature, while the
[Ni­(dmit)2] stacks form S = 1/2 one-dimensional
Heisenberg antiferromagnetic chains. Compound 1 exhibits
high conductivity at 300 K and one-dimensional variable-range hopping,
attributable to thermal fluctuations of the supramolecular channels
that modulate intracolumn transfer integrals and promote carrier localization.
To our knowledge, 1 is the first system combining transition-metal-ion
[18]­crown-6 channels with conducting [Ni­(dmit)2] layers,
establishing a supramolecular route to tune spin–charge coexistence
via host design.