Exchange Bias in a Layered Metal-Organic Topological Spin Glass.

The discovery of conductive and magnetic two-dimensional (2D) materials is critical for the development of next generation spintronics devices. Coordination chemistry in particular represents a highly versatile, though underutilized, route toward the synthesis of such materials with designer lattices. Here, we report the synthesis of a conductive, layered 2D metal-organic kagome lattice, Mn(CS), using mild solution-phase chemistry.

Strong Ferromagnetic Exchange Coupling and Single-Molecule Magnetism in MoS-Bridged Dilanthanide Complexes.

We report the synthesis and characterization of the trinuclear 4d-4f compounds [Co(CMe)][(CMe)Ln(μ-S)Mo(μ-S)Ln(CMe)], (Ln = Y, Gd, Tb, Dy), containing the highly polarizable MoS bridging unit. UV-Vis-NIR diffuse reflectance spectra and DFT calculations of reveal a low-energy metal-to-metal charge transfer transition assigned to charge transfer from the singly occupied 4d orbital of Mo to the empty 5d orbitals of the lanthanides (4d in the case of ), mediated by sulfur-based 3p orbitals. Electron paramagnetic resonance spectra collected for in a tetrahydrofuran solution show large Y hyperfine coupling constants of = 23 MHz and = 26 MHz, indicating the presence of significant yttrium-localized unpaired electron density.

Magnetic ordering through itinerant ferromagnetism in a metal-organic framework.

Materials that combine magnetic order with other desirable physical attributes could find transformative applications in spintronics, quantum sensing, low-density magnets and gas separations. Among potential multifunctional magnetic materials, metal-organic frameworks, in particular, bear structures that offer intrinsic porosity, vast chemical and structural programmability, and the tunability of electronic properties. Nevertheless, magnetic order within metal-organic frameworks has generally been limited to low temperatures, owing largely to challenges in creating a strong magnetic exchange.

Substituent Effects on Exchange Coupling and Magnetic Relaxation in 2,2'-Bipyrimidine Radical-Bridged Dilanthanide Complexes.

Systematic analysis of related compounds is crucial to the design of single-molecule magnets with improved properties, yet such studies on multinuclear lanthanide complexes with strong magnetic coupling remain rare. Herein, we present the synthesis and magnetic characterization of the series of radical-bridged dilanthanide complex salts [(Cp*Ln)(μ-5,5'-Rbpym)](BPh) (Ln = Gd, Dy; R = NMe (), OEt (), Me (), F (); bpym = 2,2'-bipyrimidine). Modification of the substituent on the bridging 5,5'-Rbpym radical anion allows the magnetic exchange coupling constant, , for the gadolinium compounds in this series to be tuned over a range from -2.

Negative cooperativity upon hydrogen bond-stabilized O adsorption in a redox-active metal-organic framework.

The design of stable adsorbents capable of selectively capturing dioxygen with a high reversible capacity is a crucial goal in functional materials development. Drawing inspiration from biological O carriers, we demonstrate that coupling metal-based electron transfer with secondary coordination sphere effects in the metal-organic framework Co(OH)(bbta) (Hbbta = 1H,5H-benzo(1,2-d:4,5-d')bistriazole) leads to strong and reversible adsorption of O. In particular, moderate-strength hydrogen bonding stabilizes a cobalt(III)-superoxo species formed upon O adsorption.