23 research outputs found
Influence of Acids on Reaction Rates of Free Radical Scavenging by TEMPO. Relevance to “Living” Free Radical Polymerizations
Intrazeolite Photochemistry. 11. Modification of the Properties of the Energy-Transfer Photosensitizer 4-Aminobenzophenone by Immobilization within Different Zeolite Microenvironments
Towards comparative investigation of Er- and Yb-based SMMs: the effect of the coordination environment configuration on the magnetic relaxation in the series of heteroleptic thiocyanate complexes
Il trattamento sanitario su minore o incapace: il miglior interesse del paziente vulnerabile fra (più) volontà e scienza.
New
{TbCu<sub>3</sub>} and {DyCu<sub>3</sub>} single-molecule magnets
(SMMs) containing a low-symmetry Ln<sup>III</sup> center (shape measurements
relative to a trigonal dodecahedron and biaugmented trigonal prism
are 2.2–2.3) surrounded by three Cu<sup>II</sup> metalloligands
are reported. SMM behavior is confirmed by frequency-dependent out-of-phase
ac susceptibility signals and single-crystal temperature and sweep
rate dependent hysteresis loops. The ferromagnetic exchange interactions
between the central Ln<sup>III</sup> ion and the three Cu<sup>II</sup> ions could be accurately measured by inelastic neutron scattering
(INS) spectroscopy and modeled effectively. The excitations observed
by INS correspond to flipping of Cu<sup>II</sup> spins and appear
at energies similar to the thermodynamic barrier for relaxation of
the magnetization, ∼15–20 K, and are thus at the origin
of the SMM behavior. The magnetic quantum number <i>M</i><sub>tot</sub> of the cluster ground state of {DyCu<sub>3</sub>}
is an integer, whereas it is a half-integer for {TbCu<sub>3</sub>},
which explains their vastly different quantum tunneling of the magnetization
behavior despite similar energy barriers