Geometry-dependent valence tautomerism, magnetism, and electrical conductivity in 1D iron-tetraoxolene chains.

Redox-active tetraoxolene ligands such as 1,4-dihydroxybenzoquinone provide access to a diversity of metal-organic architectures, many of which display interesting magnetic behavior and high electrical conductivity. Here, we take a closer look at how structure dictates physical properties in a series of 1D iron-tetraoxolene chains. Using a diphenyl-derivatized tetraoxolene ligand (HPhdhbq), we show that the steric profile of the coordinating solvent controls whether linear or helical chains are exclusively formed.

Slowing magnetic relaxation with open-shell diluents.

Strategies for slowing magnetic relaxation via local environmental design are vital for developing next-generation spin-based technologies (e.g., quantum information processing).

Dinitrogen Coordination to a High-Spin Diiron(I/II) Species.

Dinitrogen coordination to iron centers underpins industrial and biological fixation in the Haber-Bosch process and by the FeM cofactors in the nitrogenase enzymes. The latter employ local high-spin metal centers; however, iron-dinitrogen coordination chemistry remains dominated by low-valent states, contrasting the enzyme systems. Here, we report a high-spin mixed-valent cis-(μ-1,2-dinitrogen)diiron(I/II) complex [(FeBr) (μ-N )L ] (2), where [L ] is a bis(β-diketiminate) cyclophane.

A reaction-coordinate perspective of magnetic relaxation.

Understanding and utilizing the dynamic quantum properties of metal ions is the frontier of many next generation technologies. One property in particular, magnetic relaxation, is a complicated physical phenomenon that is scarcely treated in undergraduate coursework. Consequently, principles of magnetic relaxation are nearly impenetrable to starting synthetic chemists, who ultimately design the molecules that fuel new discoveries.

The Trans Effect in Electrocatalytic CO Reduction: Mechanistic Studies of Asymmetric Ruthenium Pyridyl-Carbene Catalysts.

A comprehensive mechanistic study of electrocatalytic CO reduction by ruthenium 2,2':6',2″-terpyridine (tpy) pyridyl-carbene catalysts reveals the importance of stereochemical control to locate the strongly donating N-heterocyclic carbene ligand trans to the site of CO activation. Computational studies were undertaken to predict the most stable isomer for a range of reasonable intermediates in CO reduction, suggesting that the ligand trans to the reaction site plays a key role in dictating the energetic profile of the catalytic reaction. A new isomer of [Ru(tpy)(Mebim-py)(NCCH)] (Mebim-py is 1-methylbenzimidazol-2-ylidene-3-(2'-pyridine)) and both isomers of the catalytic intermediate [Ru(tpy)(Mebim-py)(CO)] were synthesized and characterized.

Hybrid Charge-Transfer Semiconductors: (CH)SbI, (CH)BiI, and Their Halide Congeners.

Hybrid metal halides yield highly desirable optoelectronic properties and offer significant opportunity due to their solution processability. This contribution reports a new series of hybrid semiconductors, (CH)MX (M = Bi, Sb; X = Cl, Br, I), that are composed of edge-sharing MX chains separated in space by π-stacked tropylium (CH) cations; the inorganic chains resemble the connectivity of BiI. The Bi compounds have blue-shifted optical absorptions relative to the Sb compounds that span the visible and near-IR region.