Supramolecular Co(II)-[2 x 2] grids: Metamagnetic behavior in a single molecule

TL;DR

This study investigates the magnetic properties of a supramolecular Co(II) grid, revealing metamagnetic behavior and demonstrating that magnetic coupling can be tuned by ligand substituents.

Contribution

It provides new insights into the magnetic anisotropy and tunability of supramolecular Co(II) grids using single-crystal magnetization measurements.

Findings

Exhibits metamagnetic-like behavior in magnetization curves.

Magnetic coupling strength varies with ligand substituents.

Explains behavior using a minimal spin Hamiltonian.

Abstract

The magnetic anisotropy of the supramolecular [2 x 2] grid [Co(II)4L4]8+, with a bis(bipyridyl)-pyrimidine based ligand L, was investigated by single-crystal magnetization measurements at low temperatures. The magnetization curves exhibit metamagnetic like behavior and are explained by the weak-exchange limit of a minimal spin Hamiltonian including Heisenberg exchange, easy-axis ligand fields, and the Zeeman term. It is also shown that the magnetic coupling strength can be varied by the substituent R1 in the 2-position on the central pyrimidine group of the ligand L.