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Engineering intramolecular exchange interactions between magnetic metal atoms is a ubiquitous strategy for designing molecular magnets. For lanthanides, the localized nature of 4 f electrons usually results in weak exchange coupling. Mediating magnetic interactions between lanthanide ions via radical bridges is a fruitful strategy towards stronger coupling. In this work we explore the limiting case when the role of a radical bridge is played by a single unpaired electron. We synthesize an array of air-stable Ln 2 @C 80 (CH 2 Ph) dimetallofullerenes (Ln 2  = Y 2 , Gd 2 , Tb 2 , Dy 2 , Ho 2 , Er 2 , TbY, TbGd) featuring a covalent lanthanide-lanthanide bond. The lanthanide spins are glued together by very strong exchange interactions between 4 f moments and a single electron residing on the metal–metal bonding orbital. Tb 2 @C 80 (CH 2 Ph) shows a gigantic coercivity of 8.2 Tesla at 5 K and a high 100-s blocking temperature of magnetization of 25.2 K. The Ln-Ln bonding orbital in Ln 2 @C 80 (CH 2 Ph) is redox active, enabling electrochemical tuning of the magnetism. Dilanthanide complexes that possess radical bridges exhibit enhanced magnetic exchange coupling, affording molecular magnets with high blocking temperatures. Here, the authors explore a series of dilanthanide-encapsulated fullerenes where the radical bridge is taken to its limit and the role is played by a single unpaired electron.

Supported atomic metal sites have discrete molecular orbitals. Precise control over the energies of these sites is key to achieving novel reaction pathways with superior selectivity. Here, we achieve selective oxygen (O 2 ) activation by utilising a framework of cerium (Ce) cations to reduce the energy of 3 d orbitals of isolated copper (Cu) sites. Operando X-ray absorption spectroscopy, electron paramagnetic resonance and density-functional theory simulations are used to demonstrate that a [Cu(I)O 2 ] 3− site selectively adsorbs molecular O 2 , forming a rarely reported electrophilic η 2 -O 2 species at 298 K. Assisted by neighbouring Ce(III) cations, η 2 -O 2 is finally reduced to two O 2− , that create two Cu–O–Ce oxo-bridges at 453 K. The isolated Cu(I)/(II) sites are ten times more active in CO oxidation than CuO clusters, showing a turnover frequency of 0.028 ± 0.003 s −1 at 373 K and 0.01 bar P CO . The unique electronic structure of [Cu(I)O 2 ] 3− site suggests its potential in selective oxidation. Precise control over the energy of atomic metal sites is key to unlocking novel reaction pathways. Here, the authors achieve selective oxygen activation by the isolated copper site on ceria, due to its reduced 3 d orbital energy via cerium induced electron withdrawing effect.

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO2. In the first complex 1[NiIIL]0, the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second 1[NiIILH]2+ one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-CCO2 bond and the oxidation state of the central Ni atom. It was found that in the [NiLH] complex, the central atom is reduced to Ni0 and/or NiI and is thus able to bind CO2 via a single σ bond. In addition, the two-electron reduced 3[NiL]2− species also shows an affinity forwards CO2.

The stability of hybrid organic–inorganic halide perovskite semiconductors remains a significant obstacle to their application in photovoltaics. To this end, the use of low‐dimensional (LD) perovskites, which incorporate hydrophobic organic moieties, provides an effective strategy to improve their stability, yet often at the expense of their performance. To address this limitation, supramolecular engineering of noncovalent interactions between organic and inorganic components has shown potential by relying on hydrogen bonding and conventional van der Waals interactions. Here, the capacity to access novel LD perovskite structures that uniquely assemble through unorthodox S‐mediated interactions is explored by incorporating benzothiadiazole‐based moieties. The formation of S‐mediated LD structures is demonstrated, including one‐dimensional (1D) and layered two‐dimensional (2D) perovskite phases assembled via chalcogen bonding and S–π interactions. This involved a combination of techniques, such as single crystal and thin film X‐ray diffraction, as well as solid‐state NMR spectroscopy, complemented by molecular dynamics simulations, density functional theory calculations, and optoelectronic characterization, revealing superior conductivities of S‐mediated LD perovskites. The resulting materials are applied in n‐i‐p and p‐i‐n perovskite solar cells, demonstrating enhancements in performance and operational stability that reveal a versatile supramolecular strategy in photovoltaics. A new generation of low‐dimensional hybrid halide perovskite materials assembled via chalcogen bonding and S–π interactions is demonstrated by a combination of techniques, including X‐ray diffraction and solid‐state nuclear magnetic resonance spectroscopy, complemented by molecular dynamics simulations, density functional theory calculations, and optoelectronic characterization, revealing superior conductivities and enhancements in performance and operational stabilities in perovskite solar cells.

A series of polynitroxide amides possessing 2,2,5,5‐tetramethyl‐1‐pyrrolidinyloxy (PROXYL) and/or 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) units connected through various bridges were synthesized and their properties were analyzed. EPR spectroscopy provided detailed insight into their paramagnetic character and related properties. A thorough examination of the EPR spectra of dinitroxides in organic solvents provided valuable information on the intramolecular motions, thermodynamics, and spin‐exchange mechanisms. Analysis of low‐temperature X‐ and Q‐band EPR spectra of the dissolved dinitroxides provided spin–spin distances that were comparable with the theoretical values obtained by DFT. Cyclic voltammetry investigations revealed (quasi)reversible electrochemical behavior for PROXYL‐derived biradicals, whereas significant loss of the reversibility was found for TEMPO‐containing bi‐ and polyradicals. The inhibitory activities of the nitroxides against model bacteria, yeasts, and filamentous fungi were assessed. Flexibility and communication: A series of di‐ and polynitroxide amides possessing 2,2,5,5‐tetramethyl‐1‐pyrrolidinyloxy (PROXYL) and/or 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) units were synthesized and their properties were analyzed through multiple experimental techniques, including X‐ and Q‐band EPR spectroscopy, X‐ray diffraction, cyclic voltammetry, and DFT calculations (see figure). An assessment of their inhibitory activities against selected bacteria, yeasts, and filamentous fungi revealed the highest activity for TEMPO‐derived tetraradicals.

The anti ( a ) to syn ( s ) isomerization pathway of the deprotonated form of the dimer with two nickel(II) 15-membered octaazamacrocyclic units connected via a carbon–carbon (C–C) σ bond was investigated. For the initial anti ( a ) structure, a deprotonation of one of the bridging ( sp 3 hybridized) carbon atoms is suggested to allow for an a to s geometry twist. A 360° scan around the bridging C–C dihedral angle was performed first to find an intermediate geometry. Subsequently, the isomerization pathway was explored via individual steps using a series of mode redundant geometry optimizations (internal coordinates potential energy surface scans) and geometry relaxations leading to the s structure. The prominent geometries (intermediates) of the isomerization pathway are chosen and compared to the a and s structures, and geometry relaxations of the protonated forms of selected intermediates are considered.

The antioxidant activity, total phenolic and beta-glucans contents, and the fatty acid profile of total lipids in covered (black and yellow) and naked oats were studied. Oats with black hulls showed a significantly higher antioxidant activity in 2,2'-azino-di-[3-ethylbenzthiazoline sulphonate] (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) based tests in comparison with the grains with yellow hulls and those of the naked varieties. Radical scavenging activity of oats determined by electron paramagnetic resonance (EPR)/spin-trapping test did not depend on the colour of the grain hulls, but the naked grains showed a lower ability in scavenging reactive radicals. A positive correlation between the content of beta-glucans in covered oat grains and the amount of reactive radicals scavenged was observed. Total phenolic content in the black oats was significantly higher than in the yellow and naked oat varieties. However, no significant differences in the fatty acid profile between the naked and covered oats were found.

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO . In the first complex [ ] , the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second [ ] one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-C bond and the oxidation state of the central Ni atom. It was found that in the [ ] complex, the central atom is reduced to Ni and/or Ni and is thus able to bind CO via a single σ bond. In addition, the two-electron reduced [ ] species also shows an affinity forwards CO .

Turning on and off associations between molecules by a reversible change in their redox states is a convenient way of controlling self‐assembly and hence for advancing supramolecular chemistry. Here we present systematic studies on a selection of extended tetrathiafulvalenes with thienoacene spacers. By cyclic and differential pulse voltammetry and in situ EPR/UV‐Vis‐NIR spectroelectrochemistry, in combination with computations, we have elucidated how the number and orientations of thiophene rings in the spacer between the two dithiafulvene rings influence both the donor strength and association properties. The radical cations and their associates were found to cover a remarkable large region of the UV‐Vis‐NIR spectrum, but the appearance of the absorption spectrum of the radical cations as well as of the unassociated dications also depended strongly on the exact molecular structure. Cross‐conjugation versus linear conjugation: The redox properties of thienoacene‐extended tetrathiafulvalenes are strongly dependent on the orientation of the thiophene unit(s) in the spacer and hence the conjugation pathway between the two dithiafulvene rings as well as on the ability of the cations to associate (planar or non‐planar molecules).