Largely Enhancing the Blocking Energy Barrier and Temperature of a Linear Cobalt(II) Complex through the Structural Distortion: A Theoretical Exploration

Abstract

Complete-active-space self-consistent field and Nelectron valence second-order perturbation theory have both been employed to investigate the magnetic anisotropy of one two-coordinate cobalt(II) compound via altering the Co−C bond lengths and twist angle φ. The calculated energy barrier U eff decreases with the decrease in the Co−C bond lengths due to the gradually increasing interaction between the 3d orbitals of Co II and the coordination ligand field and then to the decrease in the ground orbital angular moment L of Co II . Thus, we cannot improve U eff simply by shortening the Co−C bond lengths. However, by rotating the twist angle φ from 60 to 0°, it is surprising to find that the energy barrier and blocking temperature can be enhanced up to 1559.1 cm −1 and 90 K, respectively, with φ = 0°, which are prominent even among lanthanide-based single-molecule magnets.

Modulating Two Pairs of Chiral DyIII Enantiomers by Distinct β-Diketone Ligands to Show Giant Differences in Single-Ion Magnet Performance and Nonlinear Optical Response

“…These values are larger than the experimental ones (184.35 cm –1 for R -1-Dy and 42.64 cm –1 for R -2-Dy ), which can be ascribed to the unfavorable effects, such as anharmonic phonons, Raman magnetic relaxation, QTM, etc. on the energy barrier, thus usually resulting in a smaller experimental U eff value than the calculated one. − …”

Understanding the magnetic anisotropy for linear sandwich [Er(COT)]+-based compounds: a theoretical investigation

“…11 Recently, we also theoretically predicted that the energy barrier and blocking temperature of one two-coordinate [Co(C(SiMe 2 ONaphthyl) 3 ) 2 ] 12 can be enhanced up to 1559.1 cm −1 and 90 K, respectively, through the structural distortion. 13 To date, a lot of high-performance SIMs with high energy barriers and blocking temperatures are almost Dy III -based complexes.…”

Theoretical and Experimental Studies of the Magnetostructural Correlations in Mononuclear DyIII Compounds Evidenced by Quantum Tunneling of Magnetization Time, Crystal Field Parameters, and Point Charge Electrostatic Model

“…g X–Z in eq are the principle g -factors of the ground Kramers doublet (KD) obtained from ab initio calculations (Table S8). , In spite of the precision limits due to several approximations used in the derivation, the efficiency and reliability of this method have been verified. ,,,− …”