A novel two-step transformation of aporphines into pyrroloaporphine derivatives is described with an example of model glaucine. The key step constitutes the 6,7-peri annulation of pyrrole ring onto the aporphine core.
A series of bi- and bis-1,5-diazabicyclo[3.1.0]hexanes connected by linkers through 6,6' positions were synthesized and characterized, their enthalpies of formation being high ranging within 50-115 kcal mol--1. For cyclohexane dispirotethered diazabicyclohexanes, an experimental density of 1.314 g cm--3 at 120 K was determined, which is one of the highest among related analogs. Model calculations of crystal packings were performed and compared with experimental data.
The influence of incorporating three acid additives in a MAPbI3 precursor solution on the photostability of MAPbI3 thin films under solar radiation of 60-70 mW cm−2 at a temperature of 50-60 °C in an inert atmosphere was investigated. Photostability test results were evaluated using UV-VIS spectroscopy, XRD, AFM and photoluminescence measurements. The results demonstrated that the additives, particularly N-acetylcysteine, to the perovskite precursor improved the photostability of thin films for up to 1000 h under inert conditions.
The cascade oxidative annulation of iodotriazole-tethered benzaldehydes with o-phenylenediamines provides convenient access to novel fused azaheterocyclic scaffolds incorporating 1,2,3-triazole, quinazoline, and benzimidazole cores. The use of aliphatic 1,2- and 1,3-diamines requires an additional one-pot oxidation step.
A new class of thermally activated nickel(ii) hydride precatalysts, (NHC)Ni(H)Cp, was employed in the C2-selective alkylation of furan derivatives with olefins. These well-defined complexes operated without external reducing agents such as sodium formate, thereby avoiding stoichiometric by-products. The use of optimal IMes-ligated complex afforded various alkylated furans in high to excellent yields with complete regioselectivity, broad substrate scope, and operational simplicity, representing a practical and sustainable alternative for biomass-derived furan functionalization.
Experimental data on the structural relaxation rate of silica glasses with varying OH-group content are presented. As the concentration of OH groups in silica glass decreased from 0.15 mol dm--3 to values below the detection limit, the rate of structural relaxation at 910-930 °C decreased by a factor of about 5. This effect can be associated with the formation of molecular water in silica glass, its interaction with Si atoms through coordination bonds, and the accelerated formation of larger structural elements in the glass network with a change in the average Si-O-Si bond angle.
A simple method for the preparation of nickel hydride complexes bearing N-heterocyclic carbene (NHC) ligands of general formulas [(NHC)Ni(H)(η5-Cp)] and [(NHC)2Ni(Cl)(H)] by treating readily available complexes [(NHC)Ni(Cl)(η5-Cp)] and [(NHC)2NiCl2], respectively, with sodium formate has been developed.
P-Coordinated pentacarbonyl molybdenum complexes based on cyclic secondary phosphine oxides have been synthesized by the thermal reaction of Mo(CO)6 with 3-substituted 1H-phospholane oxides in tetrahydrofuran. The structure and conformation of the synthesized complexes have been established using IR and multinuclear (1H, 13C, 31P, 95Mo) NMR spectroscopy, and simulated by DFT calculations.
New Eu3+ and Yb3+ coordination compounds with 1,10-phenanthroline-2,9-dicarboxamide derivatives and pentafluorobenzoate were synthesized with the photoluminescence quantum yields up to 30
Hydrophobic chitosan derivatives were synthesized by solvent free reactive extrusion with sorbic acid and employed as stabilizing agents for ZnS quantum dots in aqueous media. Dynamic light scattering and transmission electron microscopy revealed that hydrophobic modification leads to the formation of more uniform polymer associates and suppresses nanoparticle aggregation, resulting in stable dispersions with hydrodynamic diameters increasing from 32 nm for unmodified chitosan to 43 and 87 nm for modified derivatives with the degree of substitution of 0.08 and 0.14, respectively, while the core size remains constant (2.3--2.5 nm). The proposed green approach provides a simple route to polymer stabilized nanohybrids with tunable properties.
The cycle life of anode-free lithium batteries is limited by low Coulombic efficiency (CE) of Li deposition/dissolution on the negative current collector due to dendrite growth and poor lithiophilicity of conventional Ti. Here, we applied a highly lithiophilic coating of 2.5 μm thick germanium nanowires (NWs) onto a Ti current collector, which reduced the Li nucleation overpotential from 109 to 22 mV and increased the initial CE from 70
The modification of a glassy carbon electrode by applying voltage pulses with a steep rise time led to a significant separation (about 210 mV) between the anodic oxidation peaks of ascorbic acid and dopamine. The limits of detection for ascorbic acid and dopamine were 8 and 3 μM, respectively, and the modified electrode retained its sensitivity for approximately 30 days. The peak separation effect was attributed primarily to oxygen-containing functional groups formed on the sp2-hybridized carbon framework during electrochemical functionalization and to covalent π-π interactions between the aromatic ring of dopamine and the basal plane of the glassy carbon electrode.
A new derivative of cinnoline-fused naphthalimide was synthesized in five steps from 4-nitronaphthalic anhydride. The compound exhibits long-wavelength absorption and fluorescence in the tissue transparency window, as well as the ability to sensitize singlet oxygen formation in solution, suggesting the resulting dye as a potential theranostic for photodynamic therapy.
Diethyl dicyanofumarate reacts with β-keto nitriles under catalyst-free thermal conditions via formal [3 + 3] annulation involving Michael addition followed by intramolecular cyclization to afford 6-substituted diethyl 2-amino-4,5-dicyano-4H-pyran-3,4-dicarboxylates. With β-keto esters, the initially formed 2-aminopyran would cause aminolysis in the second equivalent of β-keto ester to deliver triethyl 4-cyano-2-(1,3-dioxoalkylamino)-4H-pyran-3,4,5-tricarboxylates.
A series of isothiouronium salts were synthesized by reacting 5-chloromethyl-7-azacoumarin-3-carboxamides with thiourea. Alkaline hydrolysis of these salts led to a new family of substituted thieno[3,4-c]pyridines. The antitumor activity of the resulting compounds was assessed.
Silicon nanocrystals were converted into orthorhombic SiP at higher phosphorus pressures than the bulk material due to the formation of a new surface. At the test temperatures of 780-840 °C, both forward and reverse reactions retained the nanoscale dimensions of particles as sintering was slow in the absence of a liquid phase.
A novel microtubule-targeting agent, an estradiol dimer based on a bis(triazole) linker, was found to cause dose-dependent disruption of the mitotic spindle, effectively inhibiting cell division. Crucially, this effect was observed at concentrations less toxic to normal cell morphology and behavior. This work addresses the urgent need for anticancer drugs with fewer side effects and identifies a promising strategy for selectively targeting microtubules.
Palladium nanoparticles supported on the commercial Al2O3, SiO2 and TiO2 carriers were tested in solvent-free dehydrogenation of decahydroquinoline at a high substrate/Pd molar ratio, with decahydroquinoline being supposed as a hydrogen storage source. The 1
DFT calculations of bond dissociation energies for donor--acceptor luminophores in thermally activated delayed fluorescence (TADF) emitters revealed the C--N single bond as the dominant structural weakness, which is strongly destabilized in the anionic state formed during charge transport, leading to the low operational stability of blue and sky-blue TADF organic light-emitting diodes (OLEDs). An alternative molecular design strategy that eliminates the weakest bond while preserving the small singlet--triplet energy gap required for efficient TADF was proposed and promising new luminophores for stable blue TADF OLEDs were suggested.
The synthesis of a ZSM-5 zeolite in H-form with b-axis oriented crystals using isomaltulose as a novel modifier of crystallization is reported. The synthesized materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and N2 sorption. The obtained ZSM-5 zeolite in H-form contains b-axis oriented crystals with a thickness of 250-300 nm; the mesopore volume and total pore volume were record-breaking for such materials: 1.03 and 1.1 cm3 g−1, respectively.
