Despite the exigent role of heterogeneous catalysts, designing them in a bottom-up fashion remains a challenge. Linear scaling relationships are, thus far, perhaps the most auspicious first-principles design methodology relating adsorbate strength to catalyst activity. Yet, the successful application of scaling relations as a general design strategy, or even rationally breaking them, is still often limited to simple reactions such as σ-bond cleavage for monodentate adsorbates, and the relationships are nearly always established on close-packed surfaces. Here, it is discussed that for σ- and π-bonds, the metal–adsorbate system has opposite energetic dependency in the offset, which is directly related to the corresponding two classes of structure sensitivity that have empirically been observed in the literature for decades. The discussed observations imply that some currently invoked theories explaining the physical and chemical principles that dominate linear scaling relationships in both inter-adsorbate and BEP linear scaling relationships perhaps do not sufficiently explain them. The discussion is aimed at broadening the applicability of this rational design principle.

Thermolysis of a 1:1 mixture of tris(di-tert-butylmethylsilyl)germane 9 and bis(di-tert-butylmethylsilyl)germane 17 at 100°C produces unexpectedly octagermacubane 18, having two 3-coordinate Ge(0) atoms (40% yield). 18 was characterized by X-ray crystallography and is a singlet biradical. Reactions of 18 with CH2Cl2 and H2O yield the novel dichloro-octagermacubane 24 and hydroxy-octagermacubane 25, respectively. Reduction of 18 with tBuMe2SiNa in THF produces an isolable octagermacubane radical anion 26-Na. Based on X-ray crystallography, EPR spectroscopy and DFT quantum mechanical calculations, 26-Na is classified as a Ge-centered radical anion.

In recent years, it was found that current passing through chiral molecules exhibits spin preference, an effect known as Chiral Induced Spin Selectivity (CISS). The effect also enables the reduction of scattering and therefore enhances delocalization. As a result, the delocalization of an exciton generated in the dots is not symmetric and relates to the electronic and hole excited spins. In this work utilizing fast spectroscopy on hybrid multilayered QDs with a chiral polypeptide linker system, we probed the interdot chiral coupling on a short time scale. Surprisingly, we found strong coherent coupling and delocalization despite having long 4-nm chiral linkers. We ascribe the results to asymmetric delocalization that is controlled by the electron spin. The effect is not measured when using shorter nonchiral linkers. As the system mimics light-harvesting antennas, the results may shed light on a mechanism of fast and efficient energy transfer in these systems.

The chemistry of selective modification of kanamycin B at the 3′- and 4′-positions of ring I and the evaluation of the resulting derivatives in cell-free translation inhibition and MIC assays are presented. The first synthesis of 3′-epi-kanamycin B (4) and its 3′-amine analogue, 3′-amino-3′- deoxy-epi-kanamycin B (5) was accomplished from commercial kanamycin B. 4′-O-alkylation retained the antibacterial activity of the parent compound and afforded protection against certain kanamycin-resistant strains. The new derivative, compound 5, showed only a moderate reduction in activity and comparative molecular dynamics simulations within the bacterial rRNA decoding site suggested that such a modification can provide excellent positioning of the desired general acid arm in the targeted catalytic antibiotic.

The development of late transition metal catalysts bearing novel ligand platforms is a convenient pathway to obtain prospective systems with enhanced catalytic performance, however, it remains a challenge in the field of olefin (co)polymerizations. In this contribution, a new family of [N,N]-type of bidentate aldimine imidazolidin-2-imine/guanidine ligands and their nickel complexes Ni1–Ni7 bearing a distinct six-membered chelate ring were successfully synthesized, and characterized. All of the nickel catalysts were active for norbornene polymerization with high activity of up to 7.44 × 10⁵ g mol^–1 h⁻¹. These catalysts also copolymerized norbornene and 1-alkenes (1-dodecene and 1-octadecene) while keeping high activities to produce various norbornene-based high-molecular-weight (M_n = 5.75–36.0 kg mol⁻¹) cyclic olefin copolymers (COCs) with adjustable 1-alkene incorporations (1.44–13.30 mol%) and a wide range of T_g values (102.2–271.4 °C). Moreover, with the decoration of bulky N-aryl substituents, these nickel catalysts exhibited strong tolerance towards polar monomer to promote the direct copolymerization of norbornene and methyl 10-undecenoate with high activity (up to 9.88 × 10⁴ g mol^–1 h⁻¹), and furnished polar functionalized COCs with a high molecular weight (M_n up to 72.4 kg mol⁻¹) and reasonable polar monomer incorporations (0.19–0.45 mol%). These nickel complexes are rare examples and also promising candidates as catalysts for the efficient synthesis of various COCs.

Biopolymers are an attractive environmentally friendly alternative to common synthetic polymers, whereas primarily proteins and polysaccharides are the biomacromolecules that are used for making the biopolymer. Due to the breadth of side chains of such biomacromolecules capable of participating in hydrogen bonding, proteins and polysaccharide biopolymers were also used for the making of proton-conductive biopolymers. Here, we introduce a new platform for combining the merits of both proteins and polysaccharides while using a glycosylated protein for making the biopolymer. We use mucin as our starting point, whereas being a waste of the food industry, it is a highly available and low-cost glycoprotein. We show how we can use different chemical strategies to target either the glycan part or specific amino acids for both crosslinking between the different glycoproteins, thus making a free-standing biopolymer, as well as for introducing superior proton conductivity properties to the formed biopolymer. The resultant proton-conductive soft biopolymer is an appealing candidate for any soft bioelectronic application.

When close to the molecular plane, the behavior of NICS as a function of the distance from the molecular plane deviates from its behavior at larger distances. By using a dense grid of NICS-probes (BQs) it is shown that, when close to the molecular plane, maximal (absolute) NICS values are obtained above the atoms. These maxima move towards the center as the grid is elevated until the (absolute) maximum NICS is obtained at the center and stay there when the grid is further elevated. It is shown that this behavior is a result of the current density, which is influenced by the electron density, according to the Biot-Savart law, which, in turn, causes the induced magnetic field which is measured by the NICS. It is thus concluded that if magnetic aromaticity is studied, the NICS calculations should be carried out at a large enough distance so that only the π-ring current affects the NICS. At distances ≥ 2 Å NICS(r)π,zz=A+B*Cr . It is suggested to use non-linear correlation for obtaining  A, B and C and extrapolate to NICS(1)π,zz and NICS(1.7)π,zz as measures for aromaticity.

Chemical reduction study of a paraphenylene comprising five para-connected aromatic rings, namely, p-quinquephenyl (C₃₀H₂₂, 1), with alkali metals in THF revealed a facile formation of the doubly reduced anion, 1^2–, which was crystallized with different alkali metal counterions. Several products were characterized using single-crystal X-ray diffraction and spectroscopic methods. The use of different alkali metals allowed tuning of metal binding in the resulting crystalline products. The consequences of electron addition and metal complexation on the core of p-quinquephenyl were investigated with the help of computational methods. Most notably, reduction results in a shift from locally aromatic to quinoidal character of 1^2–, which is mitigated by complexation to the alkali metal cations.

Colloidal nanorods based on CdS or CdSe functionalized with metal particles have proven to be efficient catalysts for light driven hydrogen evolution. Seeded CdSe@CdS nanorods have shown increasing performance with increasing rod length. This observation was rationalized by the increasing lifetime of the separated charges, as a large distance between holes localized in the CdSe seed and electrons localized at the metal tip decreases their recombination rate. However, the impact of nanorod length on electron-to-tip localization efficiency or pathway remained an open question. Therefore, we investigated the photo-induced electron transfer to the metal in a series of Ni tipped CdSe@CdS nanorods with varying length. We find that the transfer processes occurring from the region close to the semiconductor-metal interface, the rod region, and the CdSe seed region depend in different ways on the rods length. The rate of the fastest process from excitonic states generated directly at the interface is independent of the rod length but the relative amplitude decreases with increasing rod length as the weight of the interface region is decreasing. The transfer of electrons to the metal tip from excitons generated in the CdS rod region depends strongly on the length of the nanorods which indicates an electron transport limited process, i.e., electron diffusion towards the interface region followed by fast interface crossing. The transfer originating from CdSe excitonic states again shows no significant length dependence in its time constant as it is probably limited by the rate of overcoming the shallow confinement in the CdSe seed.

Nanocomposite materials consist of nanometer-sized quantum objects such as atoms, molecules, voids or nanoparticles embedded in a host material. These quantum objects can be exploited as a super-structure, which can be designed to create material properties targeted for specific applications. For electromagnetism, such targeted properties include field enhancements around the bandgap of a semiconductor used for solar cells, directional decay in topological insulators, high kinetic inductance in superconducting circuits, and many more. Despite very different application areas, all of these properties are united by the common aim of exploiting collective interaction effects between quantum objects. The literature on the topic spreads over very many different disciplines and scientific communities. In this review, we present a cross-disciplinary overview of different approaches for the creation, analysis and theoretical description of nanocomposites with applications related to electromagnetic properties.