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Photobleaching is one of the basic chemical processes that occur naturally in organic molecules. In this work, we investigate the quantum dynamics of Cy 7.5 dye molecules optically coupled to Au nanorod particles and experimentally demonstrate the decrease of the photobleaching rate in this hybrid system. We discover the effect of a resonance-like behavior not observed before for any type of emitter─the photobleaching rate of the dye molecules reaches a minimum for a suitable number of molecules coupled to the nanoparticle. The manifestation of the effect is the consequence of shifts in the energy levels in the hybrid system caused by the change in the number of molecules coupled to a nanoparticle. The energy shifts are the prerequisite for the effective depopulation of the triplet level, which is responsible for the photodegradation mechanism. The discovered effect paves the way for increasing the efficiency of optoelectronic and photovoltaic devices.

In the present work, based on the density functional theory and crystal structure prediction algorithms, we found novel structures of alkali metal orthocarbonates Li4CO4-C2/c, Na4CO4-C2/c, and K4CO...

Based on ab initio calculations within the density functional theory and crystal structure prediction algorithms, the structure and stability of iron–nitrogen compounds in the pressure range of 100...

We have synthesized the orthocarbonate Sr3[CO4]O in a laser-heated diamond anvil cell at 20 and 30 GPa by heating to ≈3000 (300) K. Afterward, we recovered the orthocarbonate with [CO4]4- groups at ambient conditions. Single-crystal diffraction shows the presence of [CO4]4- groups, i.e., sp3-hybridized carbon tetrahedrally coordinated by covalently bound oxygen atoms. The [CO4]4- tetrahedra are located in a cage formed by corner-sharing OSr6 octahedra, i.e., octahedra with oxygen as a central ion, forming an antiperovskite-type structure. At high pressures, the octahedra are nearly ideal and slightly rotated. The high-pressure phase is tetragonal (I4/mcm). Upon pressure release, there is a phase transition with a symmetry lowering to an orthorhombic phase (Pnma), where the octahedra tilt and deform slightly.

Orthocarbonates of alkaline earth metals are the newly discovered class of compounds stabilized at high pressures. Mg-orthocarbonates are the potential carbon host phases, transferring oxidized car...

Based on the ab initio calculations within the density functional theory and crystal structure prediction algorithms, the structure and stability of compounds in the Ni–S system at pressures of 100...

The mid-infrared (IR)-sensitive n/p-junction was fabricated on a p-doped silicon (Si) wafer via ultrashort laser n-type surface hyperdoping and high-temperature annealing. First, the n-type sulfur ...

A new three-component reaction leading to 1-α-(pyridyl-2-[1,2,4]triazolyl)-2-alkyl-ethanones has been discovered while studying the reactivity of monosubstituted 3,3-difluorocyclopropenes in an inverse electronic demand Diels-Alder (IEDDA) cycloaddition-cycloreversion sequence with s-tetrazines. The reaction involving the above-mentioned reactants and (benzo)pyridine as a third component results in a complex transformation proceeding in mild conditions in a stoichiometric ratio of reactants and has high functional group tolerance (phenols, amides, ethers, carboxylic acids, ketones, and acrylic esters). As a result, simple pyridines are selectively functionalized at the α-position in good isolated yields. The reaction mechanism includes a rare azaphilic [4 + 2]-cycloaddition step between s-tetrazine and intermediate 1-hydroxyindolizine, suggested after byproduct identification and tracked with a deuterium label. To date, it is only the third known example of skewed azaphilic cycloaddition of tetrazine. The reaction is truly three-component and cannot be effectively performed stepwise.

Using molecular dynamics simulation and evolutionary metadynamic calculations, a series of structures were revealed that possessed enthalpies and Gibbs energies lower than those of aragonite but hi...

Phases of CaCO3 stabilized at high pressures and temperatures are the potential agents of the global carbon cycle, transferring oxidized carbon in deep Earth’s interiors and thus are of special int...

The fluorescence-based methods of single-molecule optical detection have opened up unprecedented possibilities for imaging, monitoring, and sensing at a single-molecule level. However, single-molecule detection methods are very slow, making them practically inapplicable. In this paper, we show how to overcome this key limitation using the expanded laser spot, laser excitation in a nonfluorescent spectral window of biomolecules, and more binding fluorescent molecules on a biomolecule that increases the detection volume and the number of collected photons. We demonstrate advantages of the developed approach unreachable by any other technique using detection of single cardiac troponin-T molecules: (i) 1000-fold faster than by known approaches, (ii) real-time imaging of single troponin-T molecules dissolved in human blood serum, (iii) measurement of troponin-T concentration with a clinically important sensitivity of about 1 pg/mL. The developed approach can be used for ultrafast, ultrasensitive detection, monitoring, and real-time imaging of other biomolecules as well as of larger objects including pathogenic viruses and bacteria.

Phosphorus is one of the potential light elements of the core of the Earth and other planets. The high-pressure behavior of phosphorus compounds with nickel and iron attracts considerable attention...

A set of structures of homomolecular organic crystals with information on the solvent utilized for crystallization was extracted from the Cambridge Structural Database in order to identify possible...

Spaser nanoparticles, with ultranarrow spectral line width, small size and good biocompatibility, offer a bright prospect as potential biological probes. Sadly, over ten years since the first demon...

Spiro[imidazol-5-one-4,1'-cyclopropanes] behave as donor-acceptor (D-A) cyclopropanes in a formal cycloaddition reaction with aldehydes. The activation of such type of cyclopropanes is achieved with an equivalent of Brønsted acid. The reaction proceeds in high yields of 51-92% and demonstrates moderate diastereoselectivity at the quaternary stereocenter, which is determined by the electron-donating nature of the aldehyde partner. The ease of separation of stereoisomers allowed the creation of a library of 44 spiroannulated tetrahydrofurans with various substitution patterns.

We present a comprehensive study on the influence of Ti doping on K+ migration in the K1–xFe1–xTixO2 solid electrolyte. A novel approach is proposed which is based on modeling of configurational spaces (CSs) and full sets of inequivalent migration pathways by means of density functional theory (DFT) calculations and machine learning (ML) techniques. A 2 × 1 × 1 supercell (32 formula units) of a low-temperature polymorph of the KFeO2 compound with space group symmetry Pbca was used. For the three lowest Ti contents (x = 0.03, 0.06, and 0.09), all symmetrically inequivalent configurations of atomic arrangements (CSs) and K+ migration pathways (total numbers: 128, 59520, and 8630400) were generated. With the DFT-derived energetics of K+ migration at the lowest doping level (x = 0.03), the ML models were trained to predict ionic transport properties by using geometrical descriptors for the pathway-dopant arrangement. The trained ML models were then used to evaluate the K+ migration properties for pathways at ...

Spin-dependent band structures, the electron and spin transport, and the formation of magnetic field in the single-walled chiral gold nanotubes (n1, n2) are calculated using a relativistic lineariz...

Due to losses in metals, the propagation length of the surface plasmon-polariton (SPP) waves on metal surfaces is small. This severely limits development of numerous applications of the SPP optics: in the near-infrared spectral region propagation length of SPP waves is no longer than 200 μm as for plane SPP waves and for all types of SPP waveguides. In this work, we show that the focusing of SPPs allows for the first time realizing open-type waveguide for SPP waves characterized by long distance of SPP effective propagation length up to 1 mm at a wavelength of 780 nm. We show that focused SPP waves in such a waveguide can be effectively excited by a 16 fs laser as well as be amplitude modulated within a bandwidth about 3.5 THz. The fast dynamics of the focused SPP waves is limited by the SPP group velocity dispersion. The large effective propagation length of the SPPs and its ultra-high bandwidth open up new possibilities for using focused SPPs in different areas of plasmonics and photonics.

Synthesis of organosilicon products with a "polar" functional group within organic substituents is one of the most fundamentally and practically important challenges in today's chemistry of silicones. In our study, we suggest a solution to this problem, viz., a high-efficiency preparative method based on aerobic Co-/ N-hydroxysuccinimide (NHSI) catalyzed oxidation of p-tolylsiloxanes to p-carboxyphenylsiloxanes. This approach is based on "green", commercially available, simple, and inexpensive reagents and employs mild reaction conditions: Co(OAc)

Large-scale surface nanopatterning of a commercial silicon (Si) wafer in the form of regular 1D arrays of high-aspect-ratio vertical nanosheets (NSs) for antifouling and other potential promising optoelectronic, nanophotonic, and sensing applications was performed via multishot picosecond IR-laser ablation under a 5-mm-thick carbon disulfide liquid layer. Specifically, the nanopatterned surface layer demonstrates the broad ultralow mid-IR transmittance and the high content of sulfur, carbon, and even oxygen in the modified submicron-thick top layer, preventing the appearance of a Staphylococcus aureus bacterial biofilm. High-resolution transmission electron microscopy studies exhibit the anticorrelating inner versus outer surface abundance of donor sulfur versus adverse carbon and oxygen components and the amorphous structure of the sulfur-hyperdoped NSs atop their crystalline basements. These NSs indicate their appearance via the interfacial vapor/plume bubble-mediated codeposition of Si ablation nanoplu...

Effect of column geometry on the liquid chromatographic separations using 3D printed liquid chromatographic columns with in-column polymerized monoliths has been studied. Three different liquid chromatographic columns were designed and 3D printed in titanium as 2D serpentine, 3D spiral, and 3D serpentine columns, of equal length and i.d. Successful in-column thermal polymerization of mechanically stable poly(BuMA-co-EDMA) monoliths was achieved within each design without any significant structural differences between phases. Van Deemter plots indicated higher efficiencies for the 3D serpentine chromatographic columns with higher aspect ratio turns at higher linear velocities and smaller analysis times as compared to their counterpart columns with lower aspect ratio turns. Computational fluid dynamic simulations of a basic monolithic structure indicated 44%, 90%, 100%, and 118% higher flow through narrow channels in the curved monolithic configuration as compared to the straight monolithic configuration at linear velocities of 1, 2.5, 5, and 10 mm s

Here we have combined topological analysis, density functional theory (DFT) modeling, operando neutron diffraction, and machine learning algorithms within the comparative analysis of the known widely LiNiO2 (LNO) and LiNi0.8Co0.15Al0.05O2 (NCA) cathode materials. Full configurational spaces of the mentioned materials during delithiation were set using the topological approach starting from the 2 × 2 × 1 supercell (12 formula units in total) of the LNO structure (space group R3m). Several types of the DFT models were applied for the structural relaxation of entries of the LNO configurational space (87 configurations) demonstrating a strong dependence of the results of optimization on the initial structure guess (at the latter delithiation stages) and on the Hubbard correction application (for the whole range of delithiation). Within the computationally easiest model considered for LNO, subsequent modeling of the NCA configurational space (20760 configurations) results in structural changes of the model ce...