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Molecularly‐modified electrode materials that maintain stability over a broad pH range are rare. Typically, each electrochemical transformation necessitates a specifically tuned system to achieve strong binding and high activity of the catalyst. Here, we report the functionalisation of mesoporous indium tin oxide (mITO) electrodes with the macrocyclic host molecule pillar[6]arene (PA[6]). These electrodes are stable within the pH range of 2.4–10.8 and can be equipped with electrochemically active ruthenium complexes through host–guest interactions to perform various oxidation reactions. Benzyl alcohol oxidation serves as a model reaction in acidic media, while ammonia oxidation is conducted to assess the systems performance under basic conditions. PA[6]‐modified electrodes demonstrate catalytic activity for both reactions when complexed to different guest molecules and can be reused by reabsorption of the catalyst after its degradation. Furthermore, the system can be employed to perform subsequent reactions in electrolyte with varying pH, enabling the same electrode to be utilised in multiple different electrocatalytic reactions. [ABSTRACT FROM AUTHOR]

NiO-based nanomaterials have attracted considerable interest for different applications, which have stimulated the implementation of various synthetic approaches aimed at modulating their chemico-physical properties. In this regard, their bottom-up preparation starting from suitable precursors plays an important role, although a molecular-level insight into their reactivity remains an open issue to be properly tackled. In the present study, we focused on the fragmentation of Ni(II) diketonate-diamine adducts, of interest as vapor-phase precursors for Ni(II) oxide systems, by combining electrospray ionization mass spectrometry (ESI-MS) with multiple collisional experiments (ESI-MSn) and theoretical calculations. The outcomes of this investigation revealed common features in the fragmentation pattern of the target compounds: (i) in the first fragmentation, the three complexes yield analogous base-peak cations by losing a negatively charged diketonate moiety; in these cations, Ni-O and Ni-N interactions are stronger and the Ni positive charge is lower than in the parent neutral complexes; (ii) the tendency of ligand electronic charge to migrate towards Ni further increases in the subsequent fragmentation, leading to the formation of a tetracoordinated Ni environment featuring an interesting cation-π intramolecular interaction. [ABSTRACT FROM AUTHOR]

NiO-based films and nanostructured materials have received increasing attention for a variety of technological applications. Among the possible strategies for their fabrication, atomic layer deposition (ALD) and chemical vapor deposition (CVD), featuring manifold advantages of technological interest, represent appealing molecule-to-material routes for which a rational precursor design is a critical step. In this context, the present study is focused on the coordination sphere engineering of three heteroleptic Ni(II) β-diketonate–diamine adducts of general formula [NiL2TMEDA] [L = 1,1,1-trifluoro-2,4-pentanedionate (tfa), 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedionate (fod) or 2,2,6,6-tetramethyl-3,5-heptanedionate (thd), and TMEDA = N,N,N′,N′-tetramethylethylenediamine]. Controlled variations in the diketonate structure are pursued to investigate the influence of steric hindrance and fluorination degree on the chemico-physical characteristics of the compounds. A multi-technique investigation supported by density functional calculations highlights that all complexes are air-insensitive and monomeric and that their thermal properties and fragmentation patterns are directly dependent on functional groups in the diketonate ligands. Preliminary thermal CVD experiments demonstrate the precursors' suitability for the obtainment of NiO films endowed with flat and homogeneous surfaces, paving the way to future implementation for CVD end-uses. [ABSTRACT FROM AUTHOR]

Dye-zeolite nanomaterials are promising candidates for neurotransmitter detection, however, their sensing mechanism has remained speculative. Using ab initio molecular dynamics (AIMD) simulations, we demonstrate that water molecules play a critical role in stabilizing complexes formed between the dicationic dye and cationic neurotransmitters within the zeolite framework. This interaction exhibits binding motifs akin to those in protein-ligand complexes rather than conventional host-guest systems. Furthermore, the presence of water significantly modulates the spectroscopic properties of the nanosensor.

Nickel oxide-based thin films and nanomaterials are a current focus of intense research efforts due to the broad range of end uses in a variety of applications. While the chemico-physical properties of bulk NiO crystals, characterized by a wide band gap (4.0-4.3 eV), antiferromagnetic ordering and p-type character, have been extensively studied, for NiO films/nanomaterials the microscopic-level relationships between the surface defect structure and electronic properties are far from being completely elucidated. In the present work, we show that, by using density functional theory with the Hubbard correction (DFT+U), -OH surface defects, almost ubiquitous on oxide surfaces, can directly influence the electronic structure of NiO(100) model slabs. Depending on the exact defect chemical structure and surface defect density, the energy gap of the -OH bearing NiO(100) system can be engineered, and its behaviour can be modulated from p-type to n-type. The insights provided herein may be of importance for the modulation of NiO nanosystem properties as a function of specific applications, an important issue for their eventual real-world utilization.