The first task of CHIRALQUBIT was to undertake the detailed study of a series of spin triangles as a screening process for subsequent more detailed experiments with respect to their electric control. For this purpose, several spin triangles based on Fe(III)3, Cr(III)3, Cu(II)3 and V(IV) were either prepared for the first time, or were selected from the literature as promising candidates for electric spin control. In this latter case, their synthesis was either carried out in-house, or in collaboration with external synthetic groups.
Detailed characterizations of the spin Hamiltonian parameters of these spin triangles were conducted with multitechnique studies combining SQUID magnetometry and Electron Paramagnetic Resonance (EPR) spectroscopy. The experimental data were analyzed using detailed spin Hamiltonian models, employing detailed statistical treatment of the results. Common themes that emerged from these studies were: (i) the importance of Dzyaloshinskii-Moriya interactions in modulating the magnetic properties of those complexes and (ii) the quasi-ubiquity of distributions of the spin Hamiltonian parameters (strain effects), that need to be accounted for with a rigorous statistical treatment. These studies were reported in a series of articles, conference proceedings and lectures (see Publications I & 1 and Lectures).
Following up on those results, and based on its favourable characteristics, the ferric spin triangle [Fe3O(O2CPh)6(py)3](ClO4)·py was selected to test the theorized magnetoelectric coupling. In particular, oriented single crystals of this complex were studied using continuous-wave EPR spectroscopy, while being subjected to strong static electric fields. The experiments were carried out using custom-made sample holders developed during the course of the project. These experiments revealed that the spin of this triangle interacts with external electric fields, which consituted the first such demonstration for spin triangles. This study was reported in an peer-reviewed article and at a conference lecture (see Publications II and Lectures 4 & 5).
Publications I
4. Nitrite Reduction by Trinuclear Copper Pyrazolate Complexes: An Example of a Catalytic, Synthetic Polynuclear NO Releasing System
Inorg. Chem., 2019, 58, 7537 (DOI:10.1021/acs.inorgchem.9b00748)
3. “Determination of the distributions of the spin Hamiltonian parameters in spin triangles: a combined magnetic susceptometry and EPR spectroscopic study of the highly-symmetric [Cr3O(PhCOO)6(py)3](ClO4)·0.5py”
Inorg. Chem., 2018, 57, 13259 (DOI:10.1021/acs.inorgchem.8b01764)
2. “Interactions between H-bonded [CuII3(µ3-OH)] triangles; A combined magnetic susceptibility and EPR study”
Phys. Chem. Chem. Phys., 2018, 20, 17234 (DOI:10.1039/c8cp02643b)
1. “Towards ionic liquids with tailored magnetic properties: bmim+ salts of ferro- and antiferromagnetic CuII3 triangles”
Dalton Transactions, 2017, 46, 12263 (DOI:10.1039/c7dt02472j)
Publications II
“First Demonstration of Magnetoelectric Coupling in a Molecular Nanomagnet: Single-Crystal EPR studies of [Fe3O(O2CPh)6(py)3](ClO4)·py under static electric fields”
Chemistry, a European Journal, 2018, 24, 14896 (DOI:10.1002/chem.201803038)
Lectures:
1. Journées Scientifiques de l’Institut de Chimie de Strasbourg, Strasbourg, France, 2-3 November 2017
2. Matériaux 2018, Strasbourg Convention Centre, Strasbourg, France, 19-23 November 2018
3. Eighth North America-Greece-Cyprus Workshop on Paramagnetic Materials, Mystras, Greece, June 18-22, 2018
4. XVII International Feofilov Symposium on Spectroscopy of Crystals Doped with Rare Earth and Transition Metal Ions, Ekaternbourg, Russia, September 23-28, 2018
5. Department of Chemistry, University of Patras, Greece, October 26, 2018
