TY - JOUR
T1 - Measurement of magnetic exchange in asymmetric lanthanide dimetallics: towards a transferable theoretical framework
AU - Giansiracusa, Marcus
AU - Moreno Pineda, Eufemio
AU - Hussain, Riaz
AU - Marx, Raphael
AU - Prada, Maria Martinez
AU - Neugebauer, Petr
AU - Al-Badran, Susan
AU - Collison, David
AU - Tuna, Floriana
AU - Slageren, Joris Van
AU - Carretta, Stefano
AU - Guidi, Tatiana
AU - Mcinnes, Eric
AU - Winpenny, Richard
AU - Chilton, Nicholas
PY - 2018
Y1 - 2018
N2 - Magnetic exchange interactions within the asymmetric dimetallic compounds [hqH2][Ln2(hq)4(NO3)3]∙MeOH, (Ln = Er(III) and Yb(III), hqH = 8-hydroxyquinoline) have been directly probed with EPR spectroscopy and accurately modelled by spin Hamiltonian techniques. Exploitation of site selectivity via doping experiments in Y(III) and Lu(III) matrices yields simple EPR spectra corresponding to isolated Kramers doublets, allowing determination of the local magnetic properties of the individual sites within the dimetallic compounds. CASSCF-SO calculations, INS and far-IR measurements are all employed to further support the identification and modelling of the local electronic structure for each site. EPR spectra of the pure dimetallic compounds are highly featured and correspond to transitions within the lowest-lying exchange-coupled manifold, permitting determination of the highly anisotropic magnetic exchange between the lanthanide ions. We find a unique orientation for the exchange interaction, corresponding to a common elongated oxygen bridge for both isostructural analogs. This suggests a microscopic physical connection to the magnetic superexchange. These results are of fundamental importance for building and validating model microscopic Hamiltonians to understand the origins of magnetic interactions between lanthanides and how they may be controlled with chemistry
AB - Magnetic exchange interactions within the asymmetric dimetallic compounds [hqH2][Ln2(hq)4(NO3)3]∙MeOH, (Ln = Er(III) and Yb(III), hqH = 8-hydroxyquinoline) have been directly probed with EPR spectroscopy and accurately modelled by spin Hamiltonian techniques. Exploitation of site selectivity via doping experiments in Y(III) and Lu(III) matrices yields simple EPR spectra corresponding to isolated Kramers doublets, allowing determination of the local magnetic properties of the individual sites within the dimetallic compounds. CASSCF-SO calculations, INS and far-IR measurements are all employed to further support the identification and modelling of the local electronic structure for each site. EPR spectra of the pure dimetallic compounds are highly featured and correspond to transitions within the lowest-lying exchange-coupled manifold, permitting determination of the highly anisotropic magnetic exchange between the lanthanide ions. We find a unique orientation for the exchange interaction, corresponding to a common elongated oxygen bridge for both isostructural analogs. This suggests a microscopic physical connection to the magnetic superexchange. These results are of fundamental importance for building and validating model microscopic Hamiltonians to understand the origins of magnetic interactions between lanthanides and how they may be controlled with chemistry
U2 - 10.1021/jacs.7b10714
DO - 10.1021/jacs.7b10714
M3 - Article
SN - 0002-7863
JO - American Chemical Society. Journal
JF - American Chemical Society. Journal
ER -