Determining Key Local Vibrations in the Relaxation of Molecular Spin Qubits and Single-Molecule Magnets

A neutral auxiliary ligand enhanced dysprosium(iii) single molecule magnet

An approximately equatorial three-coordinated dysprosium(iii) complex DyL₂[N(SiMe₃)₂] (L = bis(2-(2,5-dimethyl-1H-pyrrol-1-yl)ethyl)amine) with an additional neutral auxiliary pyrrole ligand was synthesised and structurally characterized.

A belt-like one-dimensional Dy chain exhibiting slow magnetic relaxation behavior

A belt-like Dy chain compound was synthesized, which exhibited slow magnetic relaxation behavior and clear hysteresis loops below 0.6 K.

Teaching an old molecule new tricks: evidence and rationalisation of the slow magnetisation dynamics in [DyTp2Acac]

Combined analyses of magnetic and luminescence measurements, with the support of theoretical calculations, help elucidate the origin of [DyTp₂Acac]'s SMM behaviour.

A New Bis(phthalocyaninato) Terbium Single-Ion Magnet with an Overall Excellent Magnetic Performance

Bulky and strong electron-donating dibutylamino groups were incorporated onto the peripheral positions of one of the two phthalocyanine ligands in the bis(phthalocyaninato) terbium complex, resulting in the isolation of heteroleptic double-decker (Pc)Tb{Pc[N(C₄H₉)₂]₈} {Pc = phthalocyaninate; Pc[N(C₄H₉)₂]₈ = 2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyaninate} with the nature of an unsymmetrical molecular structure, a square-antiprismatic coordination geometry, an intensified coordination field strength, and the presence of organic radical-f interaction. As a total result of all these factors, this sandwich-type tetrapyrrole lanthanide single-ion magnet (SIM) exhibits an overall enhanced magnetic performance including a high blocking temperature (T_B) of 30 K and large effective spin-reversal energy barrier of U_eff = 939 K, rendering it the best sandwich-type tetrapyrrole lanthanide SIM reported thus far.

Intra-molecular origin of the spin-phonon coupling in slow-relaxing molecular magnets

We perform a systematic investigation of the spin-phonon coupling leading to spin relaxation in the prototypical mononuclear single molecule magnet [(tpaPh)Fe]-. In particular we analyze in detail the nature of the most relevant vibrational modes giving rise to the relaxation. Our fully ab initio calculations, where the phonon modes are evaluated at the level of density functional theory and the spin-phonon coupling by mapping post-Hartree-Fock electronic structures onto an effective spin Hamiltonian, reveal that acoustic phonons are not active in the spin-phonon relaxation process of dilute SMMs crystals. Furthermore, we find that intra-molecular vibrational modes produce anisotropy tensor modulations orders of magnitude higher than those associated to rotations. In light of these results we are able to suggest new designing rules for spin-long-living SMMs which go beyond the tailoring of static molecular features but fully take into account dynamical features of the vibrational thermal bath evidencing those internal molecular distortions more relevant to the spin dynamics.