Structure and Electrocatalytic Properties of Sulfur-Containing Multi-Walled Carbon Nanotubes on a Titanium Substrate Modified by a Helium Ion Beam.

In this work, a set of analytical techniques, including scanning electron microscopy (SEM), Raman scattering spectroscopy, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray microanalysis (EDX) and cyclic voltammetry (CV), were used to study the impact of high-energy He ion irradiation on the structural and electrochemical characteristics of sulfur-containing multi-walled carbon nanotubes (S-MWCNTs) placed on a titanium substrate. The results indicate that the ion beam treatment of the S-MWCNT system led to an increase in the level of imperfections on the surface structures of the nanotubes due to the formation of point defects on their outer walls and the appearance of oxygen-containing functional groups, including SO groups, near these defects. At the same time, a significant increase in the sulfur concentration (by 6.

Impact of Metal Source Structure on the Electrocatalytic Properties of Polyacrylonitrile-Derived Co-N-Doped Oxygen Reduction Reaction Catalysts.

The oxygen reduction reaction (ORR) plays a central role in energy conversion and storage technologies. A promising alternative to precious metal catalysts are non-precious metal doped carbons. Considerable efforts have been devoted to cobalt-doped carbonized polyacrylonitrile catalysts, but the optimization of their catalytic performance remains a key challenge.

Harmonizing Energies: The Interplay Between a Nonplanar SalEn-Type Molecule and a TEMPO Moiety in a New Hybrid Energy-Storing Redox-Conducting Polymer.

Redox-conducting polymers based on SalEn-type complexes have attracted considerable attention due to their potential applications in electrochemical devices. However, their charge transfer mechanisms, physical and electrochemical properties remain unclear, hindering their rational design and optimization. This study aims to establish the influence of monomer geometry on the polymer's properties by investigating the properties of novel nonplanar SalEn-type complexes, poly[N,N'-bis(salicylidene)propylene-2-(hydroxy)diaminonickel(II)], and its analog with 2,2,6,6-tetramethylpiperidinyl-N-oxyl (TEMPO)-substituted bridge (MTS).

Thermodynamic model for voltammetric responses in conducting redox polymers.

Electroactive polymer materials are known to play important roles in a vast spectrum of modern applications such as in supercapacitors, fuel cells, batteries, medicine, and smart materials, They are usually divided into two main groups: first, conducting π-conjugated organic polymers, which conduct electricity by cation-radicals delocalized over a polymer chain; second, redox polymers, which conduct electricity an electron-hopping mechanism. Polymer materials belonging to these two main groups have been thoroughly studied and their thermodynamic and kinetic models have been built. However, in recent decades a lot of mixed-type materials have been discovered and investigated.

Ligand Exchange Reaction between Ferrocene and Multiwalled Carbon Nanotubes: A Contemporary Approach.

Ligand exchange reaction (LER) between carbon nanoparticles and ferrocene (CpFe) was conducted several times, but there was no convincing evidence of half-sandwich CpFe coordination to multiwalled carbon nanotubes (MWCNT). In this study, MWCNT is modified by LER with ferrocene using AlCl/Al as a catalytic system. The modified MWCNT (Fc-MWCNT) are investigated for better understanding of the processes taking place on the surface of MWCNT using different spectroscopic and electrochemical methods.

Incorporation of a Fluorine Atom in a Bridging Ligand of Half-Lantern Pt Complexes Provides up to 10-Fold Enhancement of Electroluminescence Brightness.

The binuclear half-lantern platinum(II) complexes [Pt(pbt)(μ-SN)] (pbtH = 2-phenylbenzothiazole, SN = benzo[]thiazole-2-thiolate , 6-fluorobenzo[]thiazole-2-thiolate , 6-chlorobenzo[]thiazole-2-thiolate , 6-bromobenzo[]thiazole-2-thiolate , and 6-iodobenzo[]thiazole-2-thiolate ) were synthesized by the treatment of the in situ formed [Pt(pbt)(NCMe)]NO complex and appropriate benzo[]thiazole-2-thiole in the presence of BuOK; yield: 51-84%. Complexes - exhibit intense red photoluminescence originated from MMLCT state reaching 22% room temperature quantum yields in a CHCl solution. All complexes display excited-state decay kinetics both in solution and in the solid state; the kinetics was adequately modeled by single exponentials.

A Comparative XPS, UV PES, NEXAFS, and DFT Study of the Electronic Structure of the Salen Ligand in the H(Salen) Molecule and the [Ni(Salen)] Complex.

A comparative study of the electronic structure of the salen ligand in the H(Salen) molecule and the [Ni(Salen)] complex was performed using the experimental methods of XPS, UV PES, and NEXAFS spectroscopy along with DFT calculations. Significant chemical shifts of +1.0 eV (carbon), +1.

Investigating the Coating Effect on Charge Transfer Mechanisms in Composite Electrodes for Lithium-Ion Batteries.

The performance of lithium-ion batteries (LIBs) relies on the characteristics of the cathode material, including both intentionally applied coatings and naturally formed surface layers or binder adhesion. This study investigated the influence of the ion-permeable surface fraction, distribution, and characteristics of the coating on the performance of a lithium iron phosphate (LFP) electrode material. We developed an extended Newman-type half-cell model and examined the impact of coating parameters on the galvanostatic discharge curves of the LFP electrode material.

Mass and Charge Transfer in a Polymeric NiSalen Complex at Subzero Temperatures.

Electrochemical energy storage systems have a wide range of commercial applications. They keep energy and power even at temperatures up to +60 °C. However, the capacity and power of such energy storage systems reduce sharply at negative temperatures due to the difficulty of counterion injection into the electrode material.

Tuning the Charge Transport in Nickel Salicylaldimine Polymers by the Ligand Structure.

The conductivity of the polymeric energy storage materials is the key factor limiting their performance. Conductivity of polymeric NiSalen materials, a prospective class of energy storage materials, was found to depend strongly on the length of the bridge between the nitrogen atoms of the ligand. Polymers obtained from the complexes containing C alkyl and hydroxyalkyl bridges showed an electrical conductivity one order of magnitude lower than those derived from more common complexes with C alkyl bridges.

Optimization of Sulfonated Polycatechol:PEDOT Energy Storage Performance by the Morphology Control.

Anionic catechol-containing polymers represent a promising class of functional dopants for the capacity improvement of conductive polymers. For example, sulfonated poly(vinylcatechol) SPVC with outstanding theoretical capacity was used as a dopant for poly(ethylenedixythiophene) (PEDOT) conductive polymer, increasing its energy storage performance. However, such materials suffer from insufficient utilization of the theoretical capacity of SPVC originating from non-optimal morphology.

The Valence Band Structure of the [Ni(Salen)] Complex: An Ultraviolet, Soft X-ray and Resonant Photoemission Spectroscopy Study.

The valence band photoemission (VB PE) spectra of the [Ni(Salen)] molecular complex were measured by ultraviolet, soft X-ray and resonant photoemission (ResPE) using photons with energies ranging from 21.2 eV to 860 eV. It was found that the Ni 3d atomic orbitals' (AOs) contributions are most significant for molecular orbitals (MOs), which are responsible for the low-energy PE band at a binding energy of 3.

Photo- and Electroluminescent Neutral Iridium(III) Complexes Bearing Imidoylamidinate Ligands.

Imidoylamidinate-based heteroleptic bis(2-phenylbenzothiazole)iridium(III) and -rhodium(III) complexes [()M(NN)] ( = 2-phenylbenzothiazole, NN = '-(benzo[]thiazol-2-yl)acetimidamidyl ( and ), '-(6-fluorobenzo[]thiazol-2-yl)acetimidamidyl (), '-(benzo[]oxazol-2-yl)acetimidamidyl (), '-(1-methyl-1-benzo[]imidazol-2-yl)acetimidamidyl (); yields 70-84%) were obtained by the reaction of the in situ-generated solvento-complex [()M(NCMe)]NO and benzo[]thia/oxa/-methylimidozol-2-amines in the presence of NaOMe. Complexes - exhibited intense orange photoluminescence, reaching 37% at room temperature quantum yields, being immobilized in a poly(methyl methacrylate) matrix. A photophysical study of these species in a CHCl solution, neat powder, and frozen (77 K) MeOCHOH-EtOH glass matrix─along with density-functional theory (DFT), ab initio methods, and spin-orbit coupling time-dependent DFT calculations─verified the effects of substitution in the imidoylamidinate ligands on the excited-state properties.

The Tail Wags the Dog: The Far Periphery of the Coordination Environment Manipulates the Photophysical Properties of Heteroleptic Cu(I) Complexes.

In this work we show, using the example of a series of [Cu(Xantphos)(N^N)] complexes (N^N being substituted 5-phenyl-bipyridine) with different peripheral N^N ligands, that substituents distant from the main action zone can have a significant effect on the physicochemical properties of the system. By using the C≡C bond on the periphery of the coordination environment, three hybrid molecular systems with -Si(CH), -Au(PR), and -CHN(CH)CH fragments were produced. The Cu(I) complexes thus obtained demonstrate complicated emission behaviour, which was investigated by spectroscopic, electrochemical, and computational methods in order to understand the mechanism of energy transfer.

Electronic structure of the [Ni(Salen)] complex studied by core-level spectroscopies.

The nature and structure of occupied and empty valence electronic states (molecular orbitals, MOs) of the [Ni(Salen)] molecular complex (NiO2N2C16H14) have been studied by X-ray photoemission and absorption spectroscopy combined with density functional theory (DFT) calculations. As a result, the composition of the high-lying occupied and low-lying unoccupied electronic states has been identified. In particular, the highest occupied molecular orbital (HOMO) of the complex is found to be predominantly located on the phenyl rings of the salen ligand, while the states associated with the occupied Ni 3d-derived molecular orbitals (MOs) are at higher binding energies.

Resistivity-Temperature Behavior of Intrinsically Conducting Bis(3-methoxysalicylideniminato)nickel Polymer.

Materials with a positive temperature coefficient have many applications, including overcharge and over-temperature protection in lithium-ion (Li-ion) batteries. The thermoresistive properties of an electrically conductive polymer, based on a Ni(salen)-type backbone, known as polyNiMeOSalen, were evaluated by means of in situ resistivity measurements. It was found that the polymer was conductive at temperatures below 220 °C; however, the polymer increased in resistivity by three orders of magnitude upon reaching 250 °C.

Targeted Synthesis of NIR Luminescent Rhenium Diimine cis,trans-[Re( )(CO) (L) ] Complexes Containing N-Donor Axial Ligands: Photophysical, Electrochemical, and Theoretical Studies.

The combined action of ultraviolet irradiation and microwave heating onto acetonitrile solution of [Re( )(CO) (NCMe)]OTf ( =phenantroline and neocuproine) afforded cis,trans-Re( )(CO) (NCMe) ] acetonitrile derivatives. Substitution of relatively labile NCMe with a series of aromatic N-donor ligands (pyridine, pyrazine, 4,4'-bipyridine, N-methyl-4,4'-bipyridine) gave a novel family of the diimine cis,trans-[Re( )(CO) (L) ] complexes. Photophysical studies of the obtained compounds in solution revealed unusually high absorption across the visible region and NIR phosphorescence with emission band maxima ranging from 711 to 805 nm.

Mutually Isomeric 2- and 4-(3-nitro-1,2,4-triazol-1-yl)pyrimidines Inspired by an Antimycobacterial Screening Hit: Synthesis and Biological Activity against the ESKAPE Panel of Pathogens.

Starting from the structure of antimycobacterial screening hit OTB-021 which was devoid of activity against ESKAPE pathogens, we designed, synthesized and tested two mutually isomeric series of novel simplified analogs, 2- and 4-(3-nitro-1,2,4-triazol-1-yl)pyrimidines, bearing various amino side chains. These compounds demonstrated a reverse bioactivity profile being inactive against while inhibiting the growth of all ESKAPE pathogens (with variable potency patterns) except for Gram-negative . Reduction potentials (E, V) measured for selected compounds by cyclic voltammetry were tightly grouped in the -1.

Switching Competition between Electron and Energy Transfers in Porphyrin-Fullerene Dyads.

Porphyrin-fullerene dyads were intensively studied as molecular donor-acceptor systems providing efficient photoinduced charge separation (CS). A practical advantage of the dyads is the possibility to tune its CS process by the porphyrin periphery modification, which allows one to optimize the dyad for particular applications. However, this tuning process is typically composed of a series of trial stages involving the development of complex synthetic schemes.

Supramolecular Assembly of Metal Complexes by (Aryl)I⋅⋅⋅d [Pt ] Halogen Bonds.

The theoretical data for the half-lantern complexes [{Pt( )(μ- )} ] [1-3; is cyclometalated 2-Ph-benzothiazole; is 2-SH-pyridine (1), 2-SH-benzoxazole (2), 2-SH-tetrafluorobenzothiazole (3)] indicate that the Pt⋅⋅⋅Pt orbital interaction increases the nucleophilicity of the outer d orbitals to provide assembly with electrophilic species. Complexes 1-3 were co-crystallized with bifunctional halogen bonding (XB) donors to give adducts (1-3) ⋅(1,4-diiodotetrafluorobenzene) and infinite polymeric [1⋅1,1'-diiodoperfluorodiphenyl] . X-ray crystallography revealed that the supramolecular assembly is achieved through (Aryl)I⋅⋅⋅d [Pt ] XBs between iodine σ-holes and lone pairs of the positively charged (Pt ) centers acting as nucleophilic sites.

The (Dioximate)Ni/I System: Ligand Oxidation and Binding Modes of Triiodide Species.

Reinvestigation of (-benzoquinonedioximate)Ni/I systems demonstrated that the reaction itself and also the crystallization conditions dramatically affect the identity of generated species. Crystallization (CHCl, 20-25 °C) of the nickel(II) dioximate complex [Ni(bqoxH)] (bqoxH = -benzoquinonedioxime) with I in the 1:(1-10) molar ratios of the reactants led to several (-benzoquinonedioximate)Ni derivatives and/or iodine adducts [Ni(I)(bqoxH)(bqoxH)]·/I, [Ni(I)(bqoxH)(bqoxH)]·[Ni(bqoxH)], and [Ni(I)(bqox)(bqoxH)]·I; the latter one, featuring the anion-radical bqox ligand, is derived from the formal (-2H/1)-oxidation of bqoxH. In these three adducts, various types of noncovalent interactions were identified experimentally and their existence was supported theoretically.

Management of mild cognitive impairment (MCI): The need for national and international guidelines.

To review available evidence of pharmacological and non-pharmacological treatment for MCI and analyse information and limitations in national and international guidelines. Experts from several European countries conducted a qualitative review of the literature on MCI and treatments for MCI, as well as respective chapters in national and international guidelines on dementia/MCI. Psychotherapeutic/psychosocial treatments were excluded from the review.

Novel homogeneous photocatalyst for oxygen to hydrogen peroxide reduction in aqueous media.

An isoquinolinium-pyrrole donor-acceptor dyad was found to exhibit photocatalytic activity in oxygen-to-peroxide photoreduction with oxalate as a sacrificial electron donor. The concentration of hydrogen peroxide was shown to reach a plateau of 0.57 mM.

'Levodopa Phobia': a review of a not uncommon and consequential phenomenon.

'Levodopa Phobia' is under-recognised in Parkinson's disease but can cause profound detrimental clinical complications if left to continue. Several types can be encountered in clinical practice and can be driven by a misplaced fear of levodopa-induced dyskinesias, other gastrointestinal side effects and also the theoretical notion that levodopa may be toxic to dopaminergic neurons in the brain. The condition can be underpinned by a sense of strong influence from the physicians or carers who are unwilling to prescribe or consider levodopa, and also high levels of anxiety or even impulsive compulsive traits in patients who have been influenced by available literature or social media-based information.