Revealing the Organization of Catalytic Sequence-Defined Oligomers via Combined Molecular Dynamics Simulations and Network Analysis.

Similar to biological macromolecules such as DNA and proteins, the precise control over the monomer position in sequence-defined polymers is of paramount importance for tuning their structures and properties toward achieving specific functions. Here, we apply molecular network analysis on three-dimensional structures issued from molecular dynamics simulations to decipher how the chain organization of trifunctional catalytic oligomers is influenced by the oligomer sequence and the length of oligo(ethylene oxide) spacers. Our findings demonstrate that the tuning of their primary structures is crucial for favoring cooperative interactions between the catalytic units and thus higher catalytic activities.

Smolyak Algorithm Adapted to a System-Bath Separation: Application to an Encapsulated Molecule with Large-Amplitude Motions.

A Smolyak algorithm adapted to system-bath separation is proposed for rigorous quantum simulations. This technique combines a sparse grid method with the system-bath concept in a specific configuration without limitations on the form of the Hamiltonian, thus achieving a highly efficient convergence of the excitation transitions for the "system" part. Our approach provides a general way to overcome the perennial convergence problem for the standard Smolyak algorithm and enables the simulation of floppy molecules with more than a hundred degrees of freedom.

Spectroscopic signatures of nonpolarons: the case of diamond.

Polarons are quasi-particles made from electrons interacting with vibrations in crystal lattices. They derive their name from the strong electron-vibration polar interactions in ionic systems, that induce spectroscopic and optical signatures of such quasi-particles. In this paper, we focus on diamond, a non-polar crystal with inversion symmetry which nevertheless shows interesting signatures stemming from electron-vibration interactions, better denoted "nonpolaron" signatures in this case.

Catalytic amination of lactic acid using Ru-zeolites.

In this work we investigate the synthesis of alanine from lactic acid, a biobased platform chemical, using ammonia as a nitrogen source and Ru/zeolite catalysts. We report a high alanine selectivity when using Ru/BEA of 80-93%. Reaction side products were identified as ethanol, propionic acid or propanamide and the reaction mechanism was investigated.

Synthesis and cytotoxicity against tumor cells of pincer N-heterocyclic ligands and their transition metal complexes.

The complexes: [CoL](ClO) (1), [FeL](ClO) (2), [NiL](ClO) (3) and [MnLCl] (4), with L = diethyl-1,1'-(pyridine-2,6-diyl)bis(5-methyl-1-pyrazole-3-carboxylate), were synthesized and fully characterized. Structural analysis revealed two distinct patterns influenced by the counter ions where L acts as a tridentate chelating ligand. The antitumor activity of L and L' (diethyl 2,2'-(pyridine-2,6-diylbis(5-methyl-1-pyrazole-3,1-diyl)) diacetate) as well as their metal complexes, was tested by the measurement of their cytostatic and cytotoxic properties towards the blood cancer mastocytoma cell line P815.

Layer-by-Layer Nanoarchitectonics Using Protein-Polyelectrolyte Complexes toward a Generalizable Tool for Protein Surface Immobilization.

Layer-by-layer (LbL) self-assembly is an attractive method for the immobilization of macromolecules at interfaces. Integrating proteins in LbL thin films is however challenging due to their polyampholyte nature. Recently, we developed a method to integrate lysozyme into multilayers using protein-polyelectrolytes complexes (PPCs).

Steps towards a nature inspired inorganic crystal engineering.

This Perspective outlines the results obtained at the University of Bologna by applying crystal engineering strategies to develop nature inspired organic-inorganic materials to tackle challenges in the health and environment sectors. It is shown by means of a number of examples that co-crystallization of inorganic salts, such as alkali and transition metal halides, with organic compounds, such as amino acids, urea, thiourea and quaternary ammonium salts, can be successfully used for (i) chiral resolution and conglomerate formation from racemic compounds, (ii) inhibition of soil enzyme activity in order to reduce urea decomposition and environmental pollution, and (iii) preparation of novel agents to tackle antimicrobial resistance. All materials described in this Perspective have been obtained by mechanochemical solvent-free or slurry methods and characterized by solid state techniques.

Coordination complexes constructed from pyrazole-acetamide and pyrazole-quinoxaline: effect of hydrogen bonding on the self-assembly process and antibacterial activity.

Two mononuclear coordination complexes of -(2-aminophenyl)-2-(5-methyl-1-pyrazol-3-yl)acetamide (L), namely [Cd(L)Cl] (C) and [Cu(L)(CHOH)](NO) (C) and one mononuclear complex [Fe(L)(HO)](NO)·2HO (C), obtained after oxidation of L, have been synthesized and characterized spectroscopically. As revealed by single-crystal X-ray diffraction, each coordination sphere made of two heterocycles is completed either by two chloride anions (in C), two ethanol molecules (in C) or two water molecules (in C). The crystal packing analysis of C, C and C, revealed 1D and 2D supramolecular architectures, respectively, various hydrogen bonding interactions, which are discussed in detail.

Influence of zirconia addition in TiO and TiO-CeO aerogels on the textural, structural and catalytic properties of supported vanadia in chlorobenzene oxidation.

This paper studies the effect of the direct incorporation of ZrO in TiO and TiO-CeO aerogel supports prepared by sol-gel route on the physico-chemical and catalytic properties of supported vanadia catalysts in the total oxidation of chlorobenzene. The obtained catalysts have been characterized by means of ICP-AES, N adsorption-desorption at 77 K, XRD, XPS, H-TPR and NH-TPD. The results revealed that Zr-doped VO based catalyst is beneficial for the improvement of catalytic properties in chlorobenzene total oxidation.

Kinetics, thermodynamics, equilibrium, surface modelling, and atomic absorption analysis of selective Cu(ii) removal from aqueous solutions and rivers water using silica-2-(pyridin-2-ylmethoxy)ethan-1-ol hybrid material.

The removal of heavy metals is attracting considerable attention due to their undesirable effects on the environment. In this investigation, a new adsorbent based on silica functionalized with pyridin-2-ylmethanol (SiPy) was successfully synthesized to yield to a hybrid material. FTIR, SEM, TGA, and specific surface area analysis were used to characterize the structure and morphology of the SiPy hybrid material.

High performance recycled CFRP composites based on reused carbon fabrics through sustainable mild solvolysis route.

A novel environmentally friendly recycling method is developed for large carbon-fibers reinforced-polymers composite panels whose efficiency is demonstrated through a proof-of-concept fabrication of a new composite part based on recycled fibers. The recycling process relies on formic acid as separation reagent at room temperature and atmospheric pressure with efficient recycling potential of the separating agent. Electron microscopy and thermal analysis indicate that the recycled fibers are covered by a thin layer of about 10wt.

Quantum dynamics with curvilinear coordinates: models and kinetic energy operator.

In order to simplify the numerical solution of the time-dependent or time-independent Schrödinger equations associated with atomic and molecular motions, the use of well-adapted coordinates is essential. Usually, this set of curvilinear coordinates leads to a Hamiltonian operator that is as separable as possible. Although their corresponding kinetic energy operator (KEO) expressions can be derived for small systems or special kinds of coordinates, a and approach allows one to compute them in terms of sophisticated curvilinear coordinates.

Supramolecular Chalcogen-Bonded Semiconducting Nanoribbons at Work in Lighting Devices.

This work describes the design and synthesis of a π-conjugated telluro[3,2-β][1]-tellurophene-based synthon that, embodying pyridyl and haloaryl chalcogen-bonding acceptors, self-assembles into nanoribbons through chalcogen bonds. The ribbons π-stack in a multi-layered architecture both in single crystals and thin films. Theoretical studies of the electronic states of chalcogen-bonded material showed the presence of a local charge density between Te and N atoms.

Toward Optimized Charge Transport in Multilayer Reduced Graphene Oxides.

In the context of graphene-based composite applications, a complete understanding of charge conduction in multilayer reduced graphene oxides (rGO) is highly desirable. However, these rGO compounds are characterized by multiple and different sources of disorder depending on the chemical method used for their synthesis. Most importantly, the precise role of interlayer interaction in promoting or jeopardizing electronic flow remains unclear.

Forecasting the outcome of spintronic experiments with Neural Ordinary Differential Equations.

Deep learning has an increasing impact to assist research, allowing, for example, the discovery of novel materials. Until now, however, these artificial intelligence techniques have fallen short of discovering the full differential equation of an experimental physical system. Here we show that a dynamical neural network, trained on a minimal amount of data, can predict the behavior of spintronic devices with high accuracy and an extremely efficient simulation time, compared to the micromagnetic simulations that are usually employed to model them.

Magnesium rescues the morphology of Bacillus subtilis mreB mutants through its inhibitory effect on peptidoglycan hydrolases.

Cell wall homeostasis in bacteria is tightly regulated by balanced synthesis and degradation of peptidoglycan (PG), allowing cells to expand their sacculus during growth while maintaining physical integrity. In rod-shaped bacteria, actin-like MreB proteins are key players of the PG elongation machinery known as the Rod complex. In the Gram-positive model bacterium Bacillus subtilis depletion of the essential MreB leads to loss of rod shape and cell lysis.

Thin Films of Nanocrystalline Fe(pz)[Pt(CN)] Deposited by Resonant Matrix-Assisted Pulsed Laser Evaporation.

Prior studies of the thin film deposition of the metal-organic compound of Fe(pz)Pt[CN] (pz = pyrazine) using the matrix-assisted pulsed laser evaporation (MAPLE) method, provided evidence for laser-induced decomposition of the molecular structure resulting in a significant downshift of the spin transition temperature. In this work we report new results obtained with a tunable pulsed laser, adjusted to water resonance absorption band with a maximum at 3080 nm, instead of 1064 nm laser, to overcome limitations related to laser-target interactions. Using this approach, we obtain uniform and functional thin films of Fe(pz)Pt[CN] nanoparticles with an average thickness of 135 nm on Si and/or glass substrates.

Effect of RF Power on the Physical Properties of Sputtered ZnSe Nanostructured Thin Films for Photovoltaic Applications.

Zinc selenide (ZnSe) thin films were deposited by RF magnetron sputtering in specific conditions, onto optical glass substrates, at different RF plasma power. The prepared ZnSe layers were afterwards subjected to a series of structural, morphological, optical and electrical characterizations. The obtained results pointed out the optimal sputtering conditions to obtain ZnSe films of excellent quality, especially in terms of better optical properties, lower superficial roughness, reduced micro-strain and a band gap value closer to the one reported for the ZnSe bulk semiconducting material.

Green Synthesis of Iron-Doped Cobalt Oxide Nanoparticles from Palm Kernel Oil via Co-Precipitation and Structural Characterization.

In this study, a bio-derived precipitating agent/ligand, palm kernel oil, has been used as an alternative route for the green synthesis of nanoparticles of Fe-doped CoO via the co-precipitation reaction. The palm oil was extracted from dried palm kernel seeds by crushing, squeezing and filtration. The reaction of the palm kernel oil with potassium hydroxide, under reflux, yielded a solution containing a mixture of potassium carboxylate and excess hydroxide ions, irrespective of the length of saponification.

Spectroscopic study of the tunneling dynamics in N-water observed in the O-D stretch region.

The O-D stretch rovibrational spectra of N-DO and N-DOH were measured and analyzed. A combination band involving the in-plane N bending vibration was also observed. These bands were recorded using a pulsed-slit supersonic jet expansion and a mid-infrared tunable optical parametric oscillator.

Mutual neutralisation of O with O: investigation of the role of metastable ions in a combined experimental and theoretical study.

The mutual neutralisation of O with O has been studied in a double ion-beam storage ring with combined merged-beams, imaging and timing techniques. Branching ratios were measured at the collision energies of 55, 75 and 170 (± 15) meV, and found to be in good agreement with previous single-pass merged-beams experimental results at 7 meV collision energy. Several previously unidentified spectral features were found to correspond to mutual neutralisation channels of the first metastable state of the cation (O(D), ≈ 3.

Investigating the relationship between the mechanical properties of plasma polymer-like thin films and their glass transition temperature.

This work aims at understanding the influence of the substrate temperature () on the viscoelastic properties of propanethiol plasma polymer films (PPFs). By means of state-of-the-art AFM characterization-based techniques including peak force quantitative nanomechanical mapping (PFQNM), nano dynamic mechanical analysis (nDMA) and "scratch" experiments, it has been demonstrated that the mechanical behaviour of PPFs is dramatically affected by the thermal conditions of the substrate. Indeed, the material behaves from a high viscous liquid ( viscosity ∼ 10 Pa s) to a viscoelastic solid (loss modulus ∼ 1.

Functionalization of Mono- and Bimetallic MIL-100(Al,Fe) MOFs by Ethylenediamine: Postfunctionalization, Brønsted Acido-Basicity, and Unusual CO Sorption Behavior.

The metal sites of MIL-100(Fe), MIL-100(Fe,Al), and MIL-100(Al) metal-organic frameworks (MOFs) were decorated with ethylenediamine (EN). Interestingly, the Al-containing MOFs presented hierarchized porosity, and their structural integrity was maintained upon functionalization. Solution and solid-state NMR confirmed the grafting efficiency in the case of MIL-100(Al) and the presence of a free amine group.

Thickness Effect on Some Physical Properties of RF Sputtered ZnTe Thin Films for Potential Photovoltaic Applications.

Zinc telluride thin films with different thicknesses were grown onto glass substrates by the rf magnetron sputtering technique, using time as a variable growth parameter. All other deposition process parameters were kept constant. The deposited thin films with thickness from 75 to 460 nm were characterized using X-ray diffraction, electron microscopy, atomic force microscopy, ellipsometry, and UV-Vis spectroscopy, to evaluate their structures, surface morphology, topology, and optical properties.