Magnetic Anisotropy in Heterobimetallic Complexes

Abstract

Control of spin–orbit coupling enables the targeted modulation of coherence, catalytic, and magnetic properties in metal complexes. In this Forum, we describe our approach to exerting synthetic control over spin–orbit coupling by using heavy diamagnetic main-group metals as an external source of spin–orbit coupling. By binding these elements to first-row transition metals, we can probe the manifestation of spin–orbit coupling in their properties, by breaking spin–orbit coupling into a two-atom phenomenon. Within this approach, we focus on metal–ligand covalency and the importance of covalency in spin–orbit coupling transfer. To fully understand these systems, we need to design molecules that support careful decoupling of the influences of ligand field geometry and ligand-derived spin–orbit coupling on the magnetic anisotropy of paramagnetic transition metals. These design criteria, along with the advantages of bimetallic species, are described. We anticipate this perspective will offer a fundamental model for using two-metal systems for engendering spin–orbit coupling.

Orbital energy mismatch engenders high-spin ground states in heterobimetallic complexes

“…Compounds 3, 4, 5, and 7 form by metathesis of Ph,Me TpMCl (M ¼ Mn 2+ (1), Fe 2+ , Co 2+ , Zn 2+ (2)) 17,18 with KSnPh 3 in diethyl ether. 19 To access 6, we reacted a trimethylsilyl Ni complex with HSnPh 3 in n-hexane to eliminate trimethylsilane as 6 was unstable towards metathesis reaction conditions. Further synthetic details are available in the ESI.…”

“…S7 †); the magnetic properties of 5 were reported previously. 19 Using the program DAVE 2.0, 38 we simulated the magnetization data with the spin HamiltonianĤ…”

Slow Magnetic Relaxation in Mono‐ and Bimetallic Lanthanide Tetraimido‐Sulfate S(NtBu)42− Complexes

“…By contrast, χ M T only decreases more noticeably below 10 K for 1 a hinting at the presence of very weak antiferromagnetic coupling. Due to the half-filled felectron valence shell (4f 7 ), trivalent gadolinium ions offer the possibility to determine the magnetic exchange interaction precisely. Fitting the dc data of 1 a to a spin-only Hamiltonian Ĥ = À 2JŜ Gd(1) + À 2JŜ Gd(2) where J is the intramolecular coupling constant and Ŝ the spin operator for each paramagnetic center yielded a coupling constant of J = À 0.045(1) cm À 1 which is indicative of weak antiferromagnetic interaction between the Gd III ions.…”

“…[4] From the same spirit, the influence of a heavy atom was detected, predominantly from metal bonded heavy halides in HF EPR spectroscopy, [5] and was rationalized by theory. [6] More recently heavy main group elements bonded to the paramagnetic transition metal like germanium and tin [7] are employed in molecular arrays to take advantage of the spinorbit coupling. Within the realm of ligand design in heterobimetallic SMMs, we want to take advantage of the polyimido sulfur ligands as the SÀ N bonds range between the weak non-covalent interactions as hydrogen bonding and the strong covalent (multiple) CÀ N and CÀ O bonds.…”

Molecular Memory Switching Device Based on a Tetranuclear Organotin Sulfide Cage [(RSnIV)4(μ-S)6]·2CHCl3·4H2O (R = 2-(Phenylazo)phenyl): Synthesis, Structure, DFT Studies, and Memristive Behavior

“…However, intriguing research is still underway to develop new strategies and molecular architectures for these advanced functional hybrid memory devices with much improved performance. Main group molecular materials have attracted considerable research interest in the recent past owing to their vast potential applications in the areas such as catalysis, magnetism, spintronics, and optoelectronics. − Dehenen et al have reported an organotin sulfide cage that shows a very interesting photon up-conversion phenomenon, whereby IR wavelength is converted into visible light . Recently, Raman et al have reported a Zn complex of a phenalenyl ligand showing excellent memory device behavior .…”