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Supramolecular helices that arise from the self-assembly of small organic molecules via non-covalent interactions play an important role in the structure and properties of the corresponding materials. Here we study the supramolecular helical aggregation of oligo(phenyleneethynylene) monomers from a theoretical point of view, always guiding the studies with experimentally available data. In this way, by systematically increasing the number of monomer units, optimized n-mer geometries are obtained along with the corresponding absorption and circular dichroism spectra. For the geometry optimizations we use density functional theory together with the B3LYP-D3 functional and the 6–31G** basis set. For obtaining the spectra we resort to time-dependent density functional theory using the CAM-B3LYP functional and the 3–21G basis set. These combinations of density functional and basis set were selected after systematic convergence studies. The theoretical results are analyzed and compared to the experimentally available spectra, observing a good agreement.

Negative differential resistance (NDR) is the key feature of resonant tunneling diodes exploited for high‐frequency and low‐power devices and recent studies have focused on NDR in van der Waals heterostructures and nanoscale materials. Here, strong NDR confined along a 1‐nm‐wide 1D channel within a van der Waals layer 1T‐TaS2 is reported. Using scanning tunneling microscopy, a double 1D NDR channel formed along the sides of a charge–density‐wave domain wall of 1T‐TaS2 is found. The density functional theory calculation elucidates that the strong local band‐bending at the domain wall and the interlayer orbital overlap cooperate to bring about 1D NDR channels. Furthermore, the NDR is well controlled by changing the tunneling junction distance. This result would be important for nanoscale device applications based on strong nonlinear resistance within van der Waals material architectures. This work demonstrates 1D negative differential resistance (NDR) channels in a layered van der Waals material with charge density waves by using scanning tunneling microscopy and spectroscopy techniques. The mechanism of the NDR behavior is well elucidated. Moreover, the controllability of NDR in this system makes such nanometer‐scale 1D configuration a promising platform for logic nanodevice applications.

Here, the formation of type‐I and type‐II electronic junctions with or without any structural discontinuity along a well‐defined 1 nm‐wide 1D electronic channel within a van der Waals layer is reported. Scanning tunneling microscopy and spectroscopy techniques are employed to investigate the atomic and electronic structure along peculiar domain walls formed on the charge‐density–wave phase of 1T‐TaS2. Distinct kinds of abrupt electronic junctions with discontinuities of the band gap along the domain walls are found, some of which even do not have any structural kinks and defects. Density‐functional calculations reveal a novel mechanism of the electronic junction formation; they are formed by a kinked domain wall in the layer underneath through substantial electronic interlayer coupling. This work demonstrates that the interlayer electronic coupling can be an effective control knob over nanometer‐scale electronic property of 2D atomic monolayers. A novel interlayer coupling between domain walls in a van der Waals material 1T‐TaS2 forms abrupt 1D electronic heterojunctions even without any chemical or structural inhomogeneities within a given layer as revealed by scanning tunneling microscopy measurements and density‐functional calculations.

A series of donor–acceptor (D‐A) small molecules based on electron‐deficient benzothiadiazole (BTD) and electron‐rich benzodithiophene (BDT) featuring an A‐D‐A structure is presented. Exhaustive spectroscopic, electrochemical, and computational studies evidence their electroactive nature and their ability to form well‐ordered thin films with broad visible absorptions and low band gaps (ca. 2 eV). Time‐resolved microwave conductivity (TRMC) studies unveil unexpected n‐type charge transport displaying high electron mobilities around 0.1 cm2 V−1 s−1. Efficient electron transport properties are consistent with the low electron reorganization energies (0.11–0.17 eV) theoretically predicted. Getting electrons on the move: Acceptor‐donor‐acceptor triads based on benzothiadiazole and benzodithiophene moieties show unprecedented high electron mobilities (0.1 cm2 V−1 s−1) for these sort of low band‐gap (2.0 eV) materials (see figure). These experimental findings are explained by the calculated low reorganization energies and the good quality of the film.

Metal–organic ring interactions (MORi) represent a kind of supramolecular interaction with a stacking character, which is formed between five and/or six‐membered chelated rings; the latter occur when a pseudopeptidic‐type of ligand (malonamide‐N,N′‐dicarboxylic acid) chelates to CuII which favors a square‐planar geometry. So far, a series of CuM compounds (M=Ca, Ln) with diverse structural characteristics have been isolated, varying from discrete coordination clusters to multidimensional polymers; their common feature is the presence of five and six‐membered chelated rings stacked together. In this study, the nature of MORi was investigated at the DFT level (B3LYP‐D/TZ2P) by using an energy decomposition analysis (EDA) of the interaction energy between the two CuII complexes in the dimeric monomer unit chosen. The EDA calculations showed that the intermolecular interactions in three heterometallic CuM compounds (M=Li, Na, Ca) arise from dispersion forces, electrostatic interactions, and hydrogen bonds. Nice as pie: The nature of a metal–organic ring interactions between CuII and malonamide‐N,N′‐diacetic acid have been investigated using density functional calculations. All compounds form almost planar five‐ and six‐membered chelated rings which are stacked similarly to π–π aromatic systems, in the absence of any aromatic ring (see figure).

A simple yet general one-step solvothermal method is applied to synthesizesub-7 nm monodispersed single-crystal NiPt2 nanoparticles （NPs） with themorphology of truncated octahedrons in the alloying state of disordered atomicarrangements. The effective magnetic moments of these NPs exhibit an anomaloustemperature dependency, increasing from approximately 0.9 μB/atom at 15 K to1.9 μB/atom at 300 K. This is an increase by a factor of more than three comparedwith bulk Ni. On the basis of experiments involving X-ray absorption near-edgespectroscopy of the L3 edge for Pt and density functional theory calculations,the observed novel magnetism enhancement and its anomalous temperaturedependence are attributed to the electron transfer arising from the thermal-activation effects.

Molecular docking simulation is a very popular and well-established computational approach and has been extensively used to understand molecular interactions between a natural organic molecule (ideally taken as a receptor) such as an enzyme, protein, DNA, RNA and a natural or synthetic organic/inorganic molecule (considered as a ligand). But the implementation of docking ideas to synthetic organic, inorganic, or hybrid systems is very limited with respect to their use as a receptor despite their huge popularity in different experimental systems. In this context, molecular docking can be an efficient computational tool for understanding the role of intermolecular interactions in hybrid systems that can help in designing materials on mesoscale for different applications. The current review focuses on the implementation of the docking method in organic, inorganic, and hybrid systems along with examples from different case studies. We describe different resources, including databases and tools required in the docking study and applications. The concept of docking techniques, types of docking models, and the role of different intermolecular interactions involved in the docking process to understand the binding mechanisms are explained. Finally, the challenges and limitations of dockings are also discussed in this review. Graphical abstract

Clearly understanding elementary growth processes that depend on surface reconstruction is essential to controlling vapor-phase epitaxy more precisely. In this study, ammonia chemical adsorption on GaN(0001) reconstructed surfaces under metalorganic vapor phase epitaxy (MOVPE) conditions (3Ga-H and Nad-H + Ga-H on a 2 × 2 unit cell) is investigated using steepest-entropy-ascent quantum thermodynamics (SEAQT). SEAQT is a thermodynamic-ensemble based, first-principles framework that can predict the behavior of non-equilibrium processes, even those far from equilibrium where the state evolution is a combination of reversible and irreversible dynamics. SEAQT is an ideal choice to handle this problem on a first-principles basis since the chemical adsorption process starts from a highly non-equilibrium state. A result of the analysis shows that the probability of adsorption on 3Ga-H is significantly higher than that on Nad-H + Ga-H. Additionally, the growth temperature dependence of these adsorption probabilities and the temperature increase due to the heat of reaction is determined. The non-equilibrium thermodynamic modeling applied can lead to better control of the MOVPE process through the selection of preferable reconstructed surfaces. The modeling also demonstrates the efficacy of DFT-SEAQT coupling for determining detailed non-equilibrium process characteristics with a much smaller computational burden than would be entailed with mechanics-based, microscopic-mesoscopic approaches.

The individual and competitive adsorption of PbII, NiII, and SrII on graphene oxides (GOs) was investigated by experimental and density functional theory (DFT) studies. Experimental results indicate that 1) in all the single, binary, and ternary metal‐ion adsorption systems, the sequence of maximum adsorption capacities is PbII>NiII>SrII on GOs; 2) the desorption hysteresis of metal ions from GOs shows the adsorption affinity in the same sequence: PbII>NiII>SrII. For the first time, DFT calculations indicate that 1) PbII and NiII prefer to interact with the COH group, whereas SrII interacts with COH and COC comparably, and 2) PbII can easily the OH group from the GOs to form the much more stable Pb(OH)–GO complex. These findings are very important and useful for understanding the mechanisms of heavy‐metal‐ion adsorption on GOs and assessing the adsorption of coexisting heavy‐metal ions on GOs. Ready, set, GO! The adsorption of PbII, NiII, and SrII on graphene oxides (GOs) has been investigated by experimental and density functional theory studies. The results indicate that PbII and NiII prefer to interact with COH, whereas SrII interacts with COH and COC comparably and PbII can OH from GOs to form the more stable Pb(OH)–GO complex (see figure).

FeNC materials have shown a promising nonprecious oxygen reduction reaction (ORR) electrocatalyst yet their active site structure remains elusive. Several previous works suggest the existence of a mysterious axial ligand on the Fe center, which, however, is still unclarified. In this study, the mysterious axial ligand is identified as a hydroxyl ligand on the Fe centers and selectively promotes the ORR activities depending on different FeN4C configurations, on which the adsorption free energy of the hydroxyl ligand also differs greatly. The selective formation of hydroxyl ligand on specific FeNC configurations can resolve contradictories between previous theoretical and experimental results regarding the ORR activities and associated active configurations of FeNC catalysts. It also explains the pH‐dependent ORR activities and, moreover, a previously unreported pH‐dependent poisoning kinetics of the FeNC catalysts. An axial hydroxyl ligand on FeNC catalysts under oxygen reduction reaction (ORR) is revealed by using density functional theory calculations combined with electrochemical experiments. This uncovered ligand can close the gap between recent theoretical and experimental results regarding the active sites of FeNC catalysts. It also leads to pH‐dependent ORR activities and pH‐dependent poisoning by thiocyanates.