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In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

type:Paper, Extracts of Eurycoma longifolia Jack (EL) and Eurycoma harmandiana Pierre (EH) contain numerous bioactive compounds and varying matrices that are challenging to separate using chromatographic techniques. Herein, micellar liquid chromatography (MLC) was used to analyze canthin-6-one alkaloids contained in these extracts, and the achieved performance was compared with that of a conventional high-performance liquid chromatography (HPLC) method. The optimal mobile phase of MLC corresponded to 15 : 85 (v/v) acetonitrile : water (pH 3) containing 110 mM sodium dodecyl sulfate and 10 mM NaH_2PO_4. The retention times of canthin-6-one-9-O-b-D-glucopyranoside, 9-hydroxycanthin- 6-one, canthin-6-one, and 9-methoxycanthin-6-one were 4.78/15.42, 17.64/24.11, 32.84/38.27, and 39.04/39.86 min, respectively, in the cases of isocratic MLC and conventional HPLC. In both cases, the analyte resolution exceeded 1.5. The MLC elution behavior of the examined analytes was largely determined by their hydrophobicity and ionization. The sensitivity, precision, accuracy, and per-run acetonitrile consumption of the MLC method were comparable to those of the conventional HPLC method. However, the latter method exhibited higher performance for application to EL and EH samples, particularly those with low analyte concentrations and varying sample matrices. Overall, the analysis of canthin-6-one alkaloids using MLC was limited to trace analytes due to interference by the matrix.

type:Paper, The ionization and fragmentation processes for pentachlorobenzene were examined using a femtosecond laser emitting at 400, 800, and 1200 nm. A molecular ion was clearly observed in the mass spectrum, since the molecule can be directly ionized from the singlet electronic exited state before relaxation to triplet levels, because the pulse width of the laser is shorter than the lifetime of the excited state. Fragmentation was minimal at 1200 nm, in contrast to ionization at 800 and 400 nm. Indeed, a doubly-charged molecular ion was prominent at 800 nm, owing to the absorption band of the singly-charged molecular ion at this wavelength. Fragmentation was further enhanced at 400 nm, which can be explained by the dissociation of the doubly-charged molecular ion having a larger absorption band at 400 nm. Fragmentation was strongly affected by the absorption character of the ionic species, i.e., singly- and doubly-charged molecular ions, appeared in the process of multiphoton ionization.

MXenes are emerging sensing materials due to their metallic conductivity and rich surface chemistry for analytes; they, however, suffer from poor stability. Incorporation with functional polymers can largely prevent the performance decay and enhance the sensing performance. Herein, we demonstrate a core–shell composite, Ti₃C₂Tₓ@croconaine (poly(1,5-diaminonaphthalene-croconaine), PDAC) prepared by a facile in situ polymerization reaction, suitable for NH₃ detection. Compared to pristine Ti₃C₂Tₓ, the sensor made of a Ti₃C₂Tₓ–polycroconaine composite exhibits a significantly enhanced sensitivity of 2.8% ppm⁻¹ and an estimated achievable limit of detection of 50 ppb. The improved sensing performance could be attributed to the presence of PDAC facilitating the adsorption of NH₃ and changing the tunneling conductivity between Ti₃C₂Tₓ domains. Density functional theory (DFT) calculations reveal that the adsorption energy of NH₃ on PDAC is the highest among the tested gases, which supports the selectivity of the sensor to this analyte. Benefiting from the protection conferred by the PDAC shell, the composite has a reliable operation period of at least 40 days. In addition, we demonstrated a flexible paper-based sensor of the Ti₃C₂Tₓ@PDAC composite, without attenuated performance upon mechanical deformation. This work proposed a novel mechanism and a feasible methodology to synthesize MXene–polymer composites with improved sensitivity and stability for chemical sensing.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

Conductive polymers represent the next generation of soft, flexible electronics. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is among the most widely used of these, despite having a relatively low conductivity when deposited in the standard form with no additional chemical dopants. This is often mitigated through chemical doping, but this is associated with changes in processing easy, mechanical stability, or compatibility. This paper reports a laser micro-annealing process for PEDOT:PSS, including process optimisation, investigation of the underlying mechanism, and application in organic electronics. The laser micro-annealing increases the material conductivity from 1 S cm(-1) to around 360 S cm(-1) without any additive or post-deposition chemical treatments. This process is used, along with a laser ablation step, to fabricate organic electrochemical transistors (OECTs). These show comparable performance to material fabricated with common additives, while allowing rapid production of myriad devices. The additive and photolithography free processes enables simple fabrication of devices without the processing complications introduced by the use of additional chemicals. Following process optimisation, detailed study of the material properties suggests the dominant mechanism for this conductivity enhancement is the agglomeration of PEDOT cores within the film, facilitated by the moderate local heating action of the laser., Vodivé polymery představují novou generaci měkké, flexibilní elektroniky. Poly(3,4-ethylendioxythiofen):poly(styrensulfonát) (PEDOT:PSS) patří mezi nejpoužívanější z nich, přestože má relativně nízkou vodivost, když je nanesen ve standardní formě bez dalších chemických příměsí. To je často zmírňováno chemickým dopingem, ale to je spojeno se změnami ve snadnosti zpracování, mechanické stabilitě nebo kompatibilitě. Tento článek popisuje proces laserového mikro-žíhání pro PEDOT:PSS, včetně optimalizace procesu, zkoumání základního mechanismu a aplikace v organické elektronice. Laserové mikro-žíhání zvyšuje vodivost materiálu z 1 S cm(-1) na přibližně 360 S cm(-1) bez jakýchkoli aditivních nebo post-depozičních chemických úprav. Tento proces se používá spolu s krokem laserové ablace k výrobě organických elektrochemických tranzistorů (OECT). Ty vykazují výkon srovnatelný s materiálem vyrobeným s běžnými přísadami a zároveň umožňují rychlou výrobu řady zařízení. Procesy bez aditiv a fotolitografie umožňují jednoduchou výrobu zařízení bez komplikací při zpracování, které přináší použití dalších chemikálií. Po provedené optimalizaci procesu, podrobné studium vlastností materiálu naznačuje, že dominantním mechanismem pro toto zvýšení vodivosti je aglomerace PEDOT jader ve filmu, umožněné mírným lokálním ohřevem s pomocí laseru.

type:Paper, Extracts of Eurycoma longifolia Jack (EL) and Eurycoma harmandiana Pierre (EH) contain numerous bioactive compounds and varying matrices that are challenging to separate using chromatographic techniques. Herein, micellar liquid chromatography (MLC) was used to analyze canthin-6-one alkaloids contained in these extracts, and the achieved performance was compared with that of a conventional high-performance liquid chromatography (HPLC) method. The optimal mobile phase of MLC corresponded to 15 : 85 (v/v) acetonitrile : water (pH 3) containing 110 mM sodium dodecyl sulfate and 10 mM NaH_2PO_4. The retention times of canthin-6-one-9-O-b-D-glucopyranoside, 9-hydroxycanthin- 6-one, canthin-6-one, and 9-methoxycanthin-6-one were 4.78/15.42, 17.64/24.11, 32.84/38.27, and 39.04/39.86 min, respectively, in the cases of isocratic MLC and conventional HPLC. In both cases, the analyte resolution exceeded 1.5. The MLC elution behavior of the examined analytes was largely determined by their hydrophobicity and ionization. The sensitivity, precision, accuracy, and per-run acetonitrile consumption of the MLC method were comparable to those of the conventional HPLC method. However, the latter method exhibited higher performance for application to EL and EH samples, particularly those with low analyte concentrations and varying sample matrices. Overall, the analysis of canthin-6-one alkaloids using MLC was limited to trace analytes due to interference by the matrix.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

Molecular doping can increase the conductivity of organic semiconductors and plays an increasingly important role in emerging and established plastic electronics applications. 4-(1,3-Dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)-N,N-dimethylaniline (N-DMBI-H) and tris(pentafluorophenyl)borane (BCF) are established n- and p-dopants, respectively, but neither functions as a simple one-electron redox agent. Molecular hydrogen has been suggested to be a byproduct in several proposed mechanisms for doping using both N-DMBI-H and BCF. In this paper we show for the first time the direct detection of molecular hydrogen in the uncatalysed doping of a variety of polymeric and molecular semiconductors using these dopants. Our results provide insight into the doping mechanism, providing information complementary to that obtained from more commonly applied methods such as optical, electron spin resonance, and electrical measurements.

Angle resolved XRF (AR-XRF) is an analytical technique in which the sample is analyzed at different angles of detection or irradiation. The change in the geometry affects the intensity of the elemental characteristic emission from the sample, which depends on the in-depth distribution of analyte. In this paper, for the first time, we apply AR-XRF to gilding samples that mime real cultural heritage ones. The samples analysed, also investigated with scanning electron microscopy, present small lateral inhomogeneities and a rough surface. Moreover, we illustrate how to analyze AR-XRF data, from the collection of XRF spectra to the creation of AR-XRF profiles and the fitting of data using Sherman's equation. Using AR-XRF combined with the fundamental parameters method we calculate the massive thickness of laboratory made layered samples.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

Co-precipitation of Ni0.8Co0.1Mn0.1(OH)₂ (NCM811) and Mg-doped (0.25 wt% and 0.5 wt%) NCM811 precursors is carried out from concentrated metal sulphate solutions. In this paper, the aim is to study the role of magnesium dopant in the co-precipitation step of NCM811, the cathode active material and further the Li-ion battery cell performance. Based on the results, magnesium was fully co-precipitated in the NCM811 precursors, as expected from thermodynamic calculations. The presence of magnesium in these precursors was also confirmed by several characterization methods and magnesium was evenly distributed in the sample. It was observed that tapped density decreased and surface area increased with an expected increase in Mg content. Surprisingly, Mg doping did not improve the cyclability of coin cells, due to the stable crystal structure of NCM811. However, a slight improvement in cyclability was seen in pouch cells after 1000 cycles. A washing effect was clearly seen in lattice parameters and washing also decreased the capacity retention after 62 cycles for all samples.

Coronene (C24H12), a charge transfer complex with low-cost and high-performance energy storage, has recently attracted attention as a model molecule of graphene nano-flakes (GNFs). The stacking structures of the trimer radical cation correlate strongly with the conduction states of the GNFs. In the present paper, the structures and electronic states of the monomer, dimer and trimer radical cations of coronene were investigated by means of density functional theory calculations. In particular, the proton hyperfine coupling constants of these species were determined. The radical cation of coronene(+) (monomer) showed two structures corresponding to the (2)A(u) and B-2(3u) states due to the Jahn-Teller effect. The (2)A(u) state was more stable than the B-2(3u) state, although the energy difference between the two states was only 0.03 kcal mol(-1). The dimer and trimer radical cations took stacking structures distorted from a full overlap structure. The intermolecular distances of the molecular planes were 3.602 angstrom (dimer) and 3.564 and 3.600 angstrom (trimer). The binding energies of the dimer and trimer were calculated to be 8.7 and 13.3 kcal mol(-1), respectively. The spin density was equivalently distributed on both coronene planes in the dimer cation. In contrast, the central plane in the trimer cation had a larger spin density, rho = 0.72, than the upper and lower planes, both with rho = 0.14. The proton hyperfine coupling constants calculated from these structures and the electronic states of the monomer, dimer, and trimer radical cations of coronene were in excellent agreement with previous ESR spectra of coronene radical cations. The structures and electronic states of (coronene)(n)(+) (n = 1-3) were discussed on the basis of the theoretical results.

In this paper, we investigated the effects of the Ga loading amount and H-2 treatment temperature for the reductive solid-state ion-exchange reaction on the generated Ga species in Ga-exchanged MFI zeolites (Ga-MFIs) as well as their catalysis for ethane dehydrogenation (EDH). For the formation of isolated Ga hydrides in the zeolites, [GaH](2+) ions were preferentially formed in the low-loading Ga-MFI (Ga/Al = 0.3) treated with H-2 at 550 degrees C, corresponding to the conventional preparation conditions, (Ga-MFI-0.3(550)), while the high Ga loading (Ga/Al = 1.0) and high-temperature H-2 treatment (800 degrees C) (Ga-MFI-1.0(800)) induced the formation of [GaH2](+) ions as the major Ga hydrides, as revealed by in situ Fourier transform infrared spectroscopy including the isotope experiment using D-2. In the context of other Ga species, such as Ga+ cations and partially reduced Ga oxides (GaOX), Ga+ cations and GaOX coexist in Ga-MFI-0.3(550), as indicated by pyridine adsorption experiments. On the other hand, GaOX was hardly observed and a larger amount of Ga+ cations was formed in Ga-MFI-1.0(800). The remaining Bronsted acid sites (BASs) were also characterized by the NH3 adsorption experiment. In the EDH reaction, Ga-MFI-1.0(800) exhibited high selectivity owing to low coke formation, resulting in the highest durability among the series of Ga-MFIs tested. Under the optimized conditions, Ga-MFI-1.0(800) exhibited the highest C2H4 formation rate among previously reported Pt-free catalysts. Based on the combined results of characterization, catalyst tests, and kinetic studies, the high selectivity and durability of Ga-MFI-1.0(800) can be ascribed to the low amount of the remaining BASs by isolated Ga species ([GaH](2+), [GaH2](+) ions and Ga+ cations) as well as the major formation of [GaH2](+) ions among isolated Ga hydrides.

This review is a summary of the most up-to-date knowledge regarding assessment of atmospheric deposition of reactive nitrogen (Nr) pollutants across complex terrain in the UK. Progress in the understanding of the mechanisms and quantification of Nr deposition in areas of complex topography is slow, as no concerted attempts to measure the components of Nr in complex terrain have been made in the last decade. This is likely due to the inherent complexity of the atmospheric processes and chemical interactions which contribute to deposition in these areas. More than 300 studies have been reviewed, and we have consulted with a panel of international experts which we assembled for that purpose. We report here on key findings and knowledge gaps identified regarding measurement and modelling techniques used to quantify deposition of Nr across complex terrain in the UK, which depending on definition, may represent up to 60% of land coverage across Great Britain. The large body of peer reviewed papers, reports and other items reviewed in this study has highlighted both the strengths and weaknesses in the tools available to scientists, regulators and policy makers. This review highlights that there is no coherent global research effort to constrain the uncertainties in Nr deposition over complex terrain, despite the clearly identified risk of N deposition to ecosystems and water quality. All evidence identified that enhanced Nr deposition across complex terrain occurs, and magnitude of the enhancement is not known; however, there are major uncertainties particularly in the differences between modelled and measured wet deposition in complex terrain and representing accurate surface interactions in models. Using simplified estimates for Nr deposition, based on current understanding of current measurement and model approaches, an enhancement across UK complex terrain in the range of a factor of 1.4–2.5 (i.e. 40–150% larger than current estimates) is likely over complex upland ter

In this paper, we address the unique nature of fully textured, high surface-to-volume 3C-SiC films, as produced by intrinsic growth anisotropy, in turn generated by the high velocity of the stacking fault growth front in two-dimensional (111) platelets. Structural interpretation of high resolution scanning electron microscopy and transmission electron microscopy data is carried out for samples grown in a hot-wall low-pressure chemical vapour deposition reactor with trichlorosilane and ethylene precursors, under suitable deposition conditions. By correlating the morphology and the X-ray diffraction analysis we also point out that twinning along (111) planes is very frequent in such materials, which changes the free-platelet configuration.

This study reports a hybrid lipo-polymeric nanosystem (PDPC NPs) synthesized by a modified hydrogel-isolation technique. The ability of the nanosystem to encapsulate hydrophilic and hydrophobic molecules has been demonstrated, and their enhanced cellular uptake has been observed in vitro. The PDPC NPs, surface coated with gold by in situ reduction of chloroauric acid (PDPC-Au NPs), showed a photothermal transduction efficacy of ∼65%. The PDPC-Au NPs demonstrated an increase in intracellular ROS, triggered DNA damage and resulted in apoptotic cell death when tested against breast cancer cells (MCF-7). The disintegration of PDPC-Au NPs into smaller nanoparticles with near-infrared (NIR) laser irradiation was understood using transmission electron microscopy imaging. The lipo-polymeric hybrid nanosystem exhibited plasmon-enhanced fluorescence when loaded with IR780 (a NIR dye), followed by surface coating with gold (PDPC-IR-Au NPs). This paper is one of the first reports on the plasmon-enhanced fluorescence within a nanosystem by simple surface coating of Au, to the best of our knowledge. This plasmon-enhanced fluorescence was unique to the lipo-polymeric hybrid system, as the same was not observed with a liposomal nanosystem. The plasmon-enhanced fluorescence of PDPC-IR-Au NPs, when applied for imaging cancer cells and zebrafish embryos, showed a strong fluorescence signal at minimal concentrations of the dye. The PDPC-IR-Au NPs were also applied for photothermal therapy of breast cancer in vitro and in vivo, and the results depicted significant therapeutic benefits. © 2022 The Royal Society of Chemistry.

This study reports a hybrid lipo-polymeric nanosystem (PDPC NPs) synthesized by a modified hydrogel-isolation technique. The ability of the nanosystem to encapsulate hydrophilic and hydrophobic molecules has been demonstrated, and their enhanced cellular uptake has been observed in vitro. The PDPC NPs, surface coated with gold by in situ reduction of chloroauric acid (PDPC-Au NPs), showed a photothermal transduction efficacy of ∼65%. The PDPC-Au NPs demonstrated an increase in intracellular ROS, triggered DNA damage and resulted in apoptotic cell death when tested against breast cancer cells (MCF-7). The disintegration of PDPC-Au NPs into smaller nanoparticles with near-infrared (NIR) laser irradiation was understood using transmission electron microscopy imaging. The lipo-polymeric hybrid nanosystem exhibited plasmon-enhanced fluorescence when loaded with IR780 (a NIR dye), followed by surface coating with gold (PDPC-IR-Au NPs). This paper is one of the first reports on the plasmon-enhanced fluorescence within a nanosystem by simple surface coating of Au, to the best of our knowledge. This plasmon-enhanced fluorescence was unique to the lipo-polymeric hybrid system, as the same was not observed with a liposomal nanosystem. The plasmon-enhanced fluorescence of PDPC-IR-Au NPs, when applied for imaging cancer cells and zebrafish embryos, showed a strong fluorescence signal at minimal concentrations of the dye. The PDPC-IR-Au NPs were also applied for photothermal therapy of breast cancer in vitro and in vivo, and the results depicted significant therapeutic benefits. © 2022 The Royal Society of Chemistry.

This study reports a hybrid lipo-polymeric nanosystem (PDPC NPs) synthesized by a modified hydrogel-isolation technique. The ability of the nanosystem to encapsulate hydrophilic and hydrophobic molecules has been demonstrated, and their enhanced cellular uptake has been observed in vitro. The PDPC NPs, surface coated with gold by in situ reduction of chloroauric acid (PDPC-Au NPs), showed a photothermal transduction efficacy of ∼65%. The PDPC-Au NPs demonstrated an increase in intracellular ROS, triggered DNA damage and resulted in apoptotic cell death when tested against breast cancer cells (MCF-7). The disintegration of PDPC-Au NPs into smaller nanoparticles with near-infrared (NIR) laser irradiation was understood using transmission electron microscopy imaging. The lipo-polymeric hybrid nanosystem exhibited plasmon-enhanced fluorescence when loaded with IR780 (a NIR dye), followed by surface coating with gold (PDPC-IR-Au NPs). This paper is one of the first reports on the plasmon-enhanced fluorescence within a nanosystem by simple surface coating of Au, to the best of our knowledge. This plasmon-enhanced fluorescence was unique to the lipo-polymeric hybrid system, as the same was not observed with a liposomal nanosystem. The plasmon-enhanced fluorescence of PDPC-IR-Au NPs, when applied for imaging cancer cells and zebrafish embryos, showed a strong fluorescence signal at minimal concentrations of the dye. The PDPC-IR-Au NPs were also applied for photothermal therapy of breast cancer in vitro and in vivo, and the results depicted significant therapeutic benefits. © 2022 The Royal Society of Chemistry.

Coronene (C24H12), a charge transfer complex with low-cost and high-performance energy storage, has recently attracted attention as a model molecule of graphene nano-flakes (GNFs). The stacking structures of the trimer radical cation correlate strongly with the conduction states of the GNFs. In the present paper, the structures and electronic states of the monomer, dimer and trimer radical cations of coronene were investigated by means of density functional theory calculations. In particular, the proton hyperfine coupling constants of these species were determined. The radical cation of coronene(+) (monomer) showed two structures corresponding to the (2)A(u) and B-2(3u) states due to the Jahn-Teller effect. The (2)A(u) state was more stable than the B-2(3u) state, although the energy difference between the two states was only 0.03 kcal mol(-1). The dimer and trimer radical cations took stacking structures distorted from a full overlap structure. The intermolecular distances of the molecular planes were 3.602 angstrom (dimer) and 3.564 and 3.600 angstrom (trimer). The binding energies of the dimer and trimer were calculated to be 8.7 and 13.3 kcal mol(-1), respectively. The spin density was equivalently distributed on both coronene planes in the dimer cation. In contrast, the central plane in the trimer cation had a larger spin density, rho = 0.72, than the upper and lower planes, both with rho = 0.14. The proton hyperfine coupling constants calculated from these structures and the electronic states of the monomer, dimer, and trimer radical cations of coronene were in excellent agreement with previous ESR spectra of coronene radical cations. The structures and electronic states of (coronene)(n)(+) (n = 1-3) were discussed on the basis of the theoretical results.

type:Paper, Nanobubbles at solid–liquid interfaces play a key role in various physicochemical phenomena and it is crucial to understand their unique properties. However, little is known about their interfacial tensions due to the lack of reliable calculation methods. Based on mechanical and thermodynamic insights, we quantified for the first time the liquid–gas, solid–liquid, and solid–gas interfacial tensions of submicron-sized nitrogen bubbles at graphite–water interfaces using molecular dynamics (MD) analysis. It was revealed that Young’s equation holds even for nanobubbles with different radii. We found that the liquid–gas and solid–liquid interfacial tensions were not largely affected by the gas density inside the nanobubbles. In contrast, the size effect on the solid–gas interfacial tension was observed, namely, the value dramatically decreased upon an increase in the gas density due to gas adsorption on the solid surface. However, our quantitative evaluation also revealed that the gas density effect on the contact angles is negligible when the footprint radius is larger than 50 nm, which is a typical range observed in experiments, and thus the flat shape and stabilization of submicron-sized surface bubbles observed in experiments cannot be explained only by the changes in interfacial tensions due to the van der Waals interaction-induced gas adsorption, namely by Young’s equation without introducing the pinning effect. Based on our analysis, it was clarified that additional factors such as the differences in the studied systems are needed to explain the unresolved open issues – a satisfactory explanation for the nanobubbles in MD simulations being ultradense, non-flat, and stable without pinning.

type:Paper, Carbohydrate on the cell surfaces are known to interact not only with lectins but also other carbohydrates; the latter process is known as a carbohydrate-carbohydrate interaction. Such interactions are observed in complex oligosaccharides. It would be surprising if these interactions were observed in simple monosaccharide of mannose. In this study, the interaction between glycopolymers carrying monosaccharide of mannose was quantitatively investigated by quartz crystal microbalance measurements. We measured interactions with glycopolymer carrying mannose, galactose and glucose. Surprisingly, the interaction between the glycopolymers with mannose was much stronger than other sachcarides.

type:Paper, We report for the first time a zigzag-shaped gas phase at a highly-ordered pyrolytic graphite/water interface. The novel shape of the gaseous domain is triggered by the holes of the underlying solid-like layers, which are composed of air molecules. Specifically, many holes were created by heating in the thin solid-like layers, which roughened them. The gas domains that formed on these layers deformed from circular to zigzag-shaped as the contact lines expanded while avoiding the holes of the underlying layers. We explained the formation and growth processes of these gas structures in terms of thin film growth, which varies with the mobility of the constituent molecules.

type:Paper, Hydration structures are ubiquitous at solid/liquid interfaces and play a key role in various physicochemical and biological phenomena. Recently, it has been reported that dissolved gas molecules attracted to hydrophobic surfaces form adsorbed gas layers. Although a hydration structure and adsorbed gas layers coexist on the surface, the relationships between them remain unknown. In this study, we investigated a highly ordered pyrolytic graphite/pure water interface with and without adsorbed gas layers using frequency-modulation atomic force microscopy. We penetrated the adsorbed gas layers with the strong load force of the AFM tip and thereby obtained the frequency shift curves inside them. By comparing the curves with those measured on a bare HOPG surface, we found that the adsorbed gas layers were located at regions where the molecular density of water was low and were sandwiched between hydration layers with high water density. Moreover, the distance between adjacent hydration layers was larger than that predicted by simulations and was the same with and without the adsorbed gas layers. We propose that gas molecules on the hydrophobic surface interact with the hydration structure before forming the adsorbed gas layers, and extend the distance between hydration layers.

In this paper, we investigated the effects of the Ga loading amount and H-2 treatment temperature for the reductive solid-state ion-exchange reaction on the generated Ga species in Ga-exchanged MFI zeolites (Ga-MFIs) as well as their catalysis for ethane dehydrogenation (EDH). For the formation of isolated Ga hydrides in the zeolites, [GaH](2+) ions were preferentially formed in the low-loading Ga-MFI (Ga/Al = 0.3) treated with H-2 at 550 degrees C, corresponding to the conventional preparation conditions, (Ga-MFI-0.3(550)), while the high Ga loading (Ga/Al = 1.0) and high-temperature H-2 treatment (800 degrees C) (Ga-MFI-1.0(800)) induced the formation of [GaH2](+) ions as the major Ga hydrides, as revealed by in situ Fourier transform infrared spectroscopy including the isotope experiment using D-2. In the context of other Ga species, such as Ga+ cations and partially reduced Ga oxides (GaOX), Ga+ cations and GaOX coexist in Ga-MFI-0.3(550), as indicated by pyridine adsorption experiments. On the other hand, GaOX was hardly observed and a larger amount of Ga+ cations was formed in Ga-MFI-1.0(800). The remaining Bronsted acid sites (BASs) were also characterized by the NH3 adsorption experiment. In the EDH reaction, Ga-MFI-1.0(800) exhibited high selectivity owing to low coke formation, resulting in the highest durability among the series of Ga-MFIs tested. Under the optimized conditions, Ga-MFI-1.0(800) exhibited the highest C2H4 formation rate among previously reported Pt-free catalysts. Based on the combined results of characterization, catalyst tests, and kinetic studies, the high selectivity and durability of Ga-MFI-1.0(800) can be ascribed to the low amount of the remaining BASs by isolated Ga species ([GaH](2+), [GaH2](+) ions and Ga+ cations) as well as the major formation of [GaH2](+) ions among isolated Ga hydrides.

Optical control of polyatomic molecules promises new opportunities in precision metrology and fundamental chemistry, as well as quantum information and many-body science. Contemporary experimental and theoretical efforts have mostly focused on cycling photons via excitation of a single electron localized to an alkaline earth (group 2)-like metal center. In this paper, we consider pathways towards optical cycling in polyatomic molecules with multi-electron degrees of freedom, which arise from two or more cycling electrons localized to p-block post-transition metal and metalloid (group 13, 14, and 15) centers. We characterize the electronic structure and rovibrational branching of several prototypical candidates using ab initio quantum chemical methods. Despite increased internal complexity and challenging design parameters, we find several molecules possessing quasi-closed photon cycling schemes with highly diagonal, visible and near-infrared transitions. Furthermore, we identify new heuristics for engineering optically controllable and laser-coolable polyatomic molecules with multi-electron cycling centers. Our results help elucidate the interplay between hybridization, repulsion, and ionicity in optically active species and provide new directions for using polyatomic molecules with complex electronic structure as a resource for quantum science and measurement.

A major challenge in the field of microfluidics is to predict and control drop interactions. This work develops an image-based data-driven model to forecast drop dynamics based on experiments performed on a microfluidics device. Reduced-order modelling techniques are applied to compress the recorded images into low-dimensional spaces and alleviate the computational cost. Recurrent neural networks are then employed to build a surrogate model of drop interactions by learning the dynamics of compressed variables in the reduced-order space. The surrogate model is integrated with real-time observations using data assimilation. In this paper we developed an ensemble-based latent assimilation algorithm scheme which shows an improvement in terms of accuracy with respect to the previous approaches. This work demonstrates the possibility to create a reliable data-driven model enabling a high fidelity prediction of drop interactions in microfluidics device. The performance of the developed system is evaluated against experimental data (i.e., recorded videos), which are excluded from the training of the surrogate model. The developed scheme is general and can be applied to other dynamical systems.

In the field of air analysis, highlights within this review period included: a review paper of developments in new personal air samplers for workplace air measurements; a new passive air sampler for Hg0; new filter-based RMs; a new field-deployable carbon analyser for speciation measurements of carbonaceous aerosols and advances in the measurement of RCS using vibrational spectroscopic techniques. The maturity of AAS methods for the analysis of waters was highlighted this year by the lack of significant developments. All the novelty was in sample preparation as reflected in Tables 1 and 2. The tables also reflect the large interest in the use of graphene oxide as a solid phase for preconcentration and the continued use of magnetic nanoparticles. There are now enough methods and application to warrant the inclusion of the analysis of nanoparticles as a separate section rather than as a subsection in speciation. This trend is set to continue as instrumental improvements allow lower size LODs and the determination of lower particle numbers. Notable advances in the analysis of soils and plants included work on the preparation of new RMs as alternatives to NIST soil SRMs that are now in short supply. There was increased interest in the development of miniaturised AES instruments with the potential for field deployment. In the analysis of soil by LIBS, more studies included some form of external validation e.g. comparison with results of an established analytical method, which is most welcome. The availability of well-characterised matrix-matched reference materials continues to be a limitation in the production of high-quality geoanalytical data, particularly when exploring the fine structure of geological materials by microanalytical techniques such as LA-ICP-MS and SIMS. It is heartening to see that many of the researchers working in this area appreciate the importance of making new RMs available to the wider geochemical community. Although the development of portable

Earth-abundant, cheap and non-toxic zinc-based coordination compounds are drawing research attention as promising candidates for various applications, such as photoluminescent materials and anticancer agents. In this paper we report six zinc complexes (1-3-NO3 and 1-3-Cl) with pyridyl-based thiazolyl-hydrazone ligands, which differ in the nature of substituents at the ligands' periphery, anion type, and geometry around the metal ion. The complexes were characterized by single-crystal and powder X-ray diffraction analysis, as well as IR and NMR spectroscopy. The symmetrical complexes 2-Cl and 3-Cl, where zinc atoms are located at a two-fold axis, do not exhibit photophysical properties, unlike their asymmetrical analogs 2-NO3 and 3-NO3 with the same complex cation. Asymmetrical pentacoordinated 1-Cl and hexacoordinated 1-NO3 complexes exhibit photophysical properties. An admixture of allowed intra-ligand (1IL) and chloro (X)-to-ligand charge-transfer (1XLCT) electronic transitions is responsible for the fluorescence of the 1-Cl complex. The origin of the emission of the 1-NO3 complex is ascribed to an admixture of 3IL and ligand-to-ligand charge-transfer (3LLCT) forbidden electronic transitions, while for 3-NO3 most electronic excitations are of LLCT character. The thermal stability of the complexes is in accord with the strength of respective intermolecular interactions. The antiproliferative activity of the complexes was in the nanomolar range on some of the investigated cancer cell lines. Contrary to the increase of antiproliferative activity of the complexes in comparison to the free ligands in cancer cell lines, an acute toxicity determined in the brine shrimp assay follows the opposite trend. The overall results suggest that Zn(ii) thiazoyl-hydrazone complexes have considerable potential as multifunctional materials.

Two anomalous broad bands are usually found in the Raman spectrum of bulk and 2D Te-based chalcogenides, which include binary compounds, like ZnTe, CdTe, HgTe, GaTe, GeTe, SnTe, PbTe, GeTe2, As2Te3, Sb2Te3, Bi2Te3, NiTe2, IrTe2, and TiTe2, as well as ternary compounds, like GaGeTe, SnSb2Te4, SnBi2Te4, and GeSb2Te5. Many different explanations have been proposed in the literature for the origin of the anomalous broad bands in tellurides, usually located between 119 and 145 cm(-1). They have been attributed to the intrinsic Raman modes of the sample, to oxidation of the sample, to the folding of Brillouin-edge modes onto the zone center, to the existence of a double resonance, like that of graphene, or to the formation of Te precipitates. In this paper, we provide arguments to demonstrate that such bands correspond to clusters or precipitates of trigonal Te in the form of nanosize or microsize grains or layers that are segregated either inside or at the surface of the samples. Several mechanisms for Te segregation are discussed and sample heating caused by excessive laser power during Raman scattering measurements is emphasized. Besides, we show that anomalous Raman modes related to Se precipitates also occur in selenides, thus providing a general vision for better characterization of selenides and tellurides by means of Raman scattering measurements and for a better understanding of chalcogenides in general., V Ramanově spektru mnoha chalkogenidů na bázi Te se obvykle nacházejí dva široké pásy. Ty se objevují v binárních sloučeninách jako je ZnTe, CdTe, HgTe, GaTe, GeTe, SnTe, PbTe, GeTe2, As2Te3, Sb2Te3, Bi2Te3, NiTe2, IrTe2, TiTe2, stejně tak jako v ternárních sloučeninách, jako je GaGeTe, SnSb2Te4, SnBi2Te4 a GeSb2Te5. Tyto dva široké anomální pásy se obvykle nalézají mezi 119 a 145 cm-1 . V literatuře nalézáme mnoho různých vysvětlení původu těchto dvou pásů v telluridech. Jsou připisovány vlastnímu vzorku, oxidaci, skládání Brillouin-edge módů do středu zóny, existenci dvojité rezonance, jako je např. u grafenu, nebo tvorbě Te precipitátů. V tomto článku předkládáme argumenty, které ukazují, že takové pásy odpovídají právě shlukům nebo precipitátům trigonálního Te ve formě nano- nebo mikro-zrn nebo vrstev, které jsou segregovány buď uvnitř nebo na povrchu vzorku. Diskutujeme několik mechanismů pro segregaci Te a dále vliv zahřívání vzorku na tuto segregaci v důsledku nadměrného výkonu laseru během měření Ramanova rozptylu. Dále ukazujeme, že anomální Ramanovy módy související s precipitáty Se se obecně vyskytují také v selenidech. Tyto závěry poskytují obecný pohled na charakterizaci selenidů a teluridů pomocí Ramanova rozptylu usnadňují pochopení chalkogenidů obecně.

The development of hybrid nanoscintillators is hunted for the implementation of modern detection technologies, like in high energy physics, homeland security, radioactive gas sensing, and medical imaging, as well as of the established therapies in radiation oncology, such as in X-ray activated photodynamic therapy. Engineering of the physico-chemical properties of nanoparticles (NPs) enables the manufacture of hybrids in which the conjugation of inorganic/organic components leads to increased multifunctionality and performance. However, the optimization of the properties of nanoparticles in combination with the use of ionizing radiation is not trivial: a complete knowledge on the structure, composition, physico-chemical features, and scintillation property relationships in hybrid nanomaterials is pivotal for any applications exploiting X-rays. In this paper, the design of hybrid nanoscintillators based on ZnO grown onto porous SiO2 substrates (ZnO/SiO2) has been performed in the view to create nanosystems potentially suitable in X-ray activated photodynamic therapy. Indeed, cytotoxic porphyrin dyes with increasing concentrations have been anchored on ZnO/SiO2 nanoparticles through amino-silane moieties. Chemical and structural analyses correlated with photoluminescence reveal that radiative energy transfer between ZnO and porphyrins is the principal mechanism prompting the excitation of photosensitizers. The use of soft X-ray excitation results in a further sensitization of the porphyrin emission, due to augmented energy deposition promoted by ZnO in the surroundings of the chemically bound porphyrin. This finding unveils the cruciality of the design of hybrid nanoparticles in ruling the efficacy of the interaction between ionizing radiation and inorganic/organic moieties, and thus of the final nanomaterial performances towards the foreseen application.

In this paper, we report the synthesis of dianionic amidophosphineborane-supported titanium chloride [{Ph2P(BH3)N}2C6H4TiCl2] (1) and TiIV alkyl complex [{Ph2P(BH3)N}2C6H4Ti(CH2SiMe3)2] (2) using a salt metathesis reaction. TiIV complex 1 was obtained by the reaction of the bis-borane ligand [{Ph2P(BH3)NH}2C6H4] and TiCl4 in toluene followed by the addition of 2 equivalents of [LiN(SiMe3)2] at ambient temperature. TiIV bis-alkyl complex 2 was isolated from the reaction of complex 1 with 2.5 equivalents of LiCH2SiMe3 in toluene. The solid-state structure of complex 1 is established by single-crystal X-ray diffraction analysis. TiIV bis-alkyl complex 2 has proved to be a competent catalyst in the deoxygenative reduction of aliphatic and aromatic esters with pinacolborane (HBpin) to afford corresponding boryl ethers at room temperature under solvent-free conditions. Catalyst 2 exhibits chemoselectivity toward ester functionalities over halides, heteroatoms, olefins, and amino functional groups. DFT studies demonstrate that the active form of catalyst 2 is capable of easily transferring its hydrides to ester substrates at room temperature. The studies further reveal that the rate-limiting step (RLS) in an ester-to-boryl ether conversion is the cleavage of the C-O bond of an ester. In brief, the titanium-catalysed ester-to-boryl ether conversions are found to be downhill processes having small activation barriers along all mechanistic steps. © 2022 The Royal Society of Chemistry.

In this paper, we report the synthesis of dianionic amidophosphineborane-supported titanium chloride [{Ph2P(BH3)N}2C6H4TiCl2] (1) and TiIV alkyl complex [{Ph2P(BH3)N}2C6H4Ti(CH2SiMe3)2] (2) using a salt metathesis reaction. TiIV complex 1 was obtained by the reaction of the bis-borane ligand [{Ph2P(BH3)NH}2C6H4] and TiCl4 in toluene followed by the addition of 2 equivalents of [LiN(SiMe3)2] at ambient temperature. TiIV bis-alkyl complex 2 was isolated from the reaction of complex 1 with 2.5 equivalents of LiCH2SiMe3 in toluene. The solid-state structure of complex 1 is established by single-crystal X-ray diffraction analysis. TiIV bis-alkyl complex 2 has proved to be a competent catalyst in the deoxygenative reduction of aliphatic and aromatic esters with pinacolborane (HBpin) to afford corresponding boryl ethers at room temperature under solvent-free conditions. Catalyst 2 exhibits chemoselectivity toward ester functionalities over halides, heteroatoms, olefins, and amino functional groups. DFT studies demonstrate that the active form of catalyst 2 is capable of easily transferring its hydrides to ester substrates at room temperature. The studies further reveal that the rate-limiting step (RLS) in an ester-to-boryl ether conversion is the cleavage of the C-O bond of an ester. In brief, the titanium-catalysed ester-to-boryl ether conversions are found to be downhill processes having small activation barriers along all mechanistic steps. © 2022 The Royal Society of Chemistry.

In this paper, we report the synthesis of dianionic amidophosphineborane-supported titanium chloride [{Ph2P(BH3)N}2C6H4TiCl2] (1) and TiIV alkyl complex [{Ph2P(BH3)N}2C6H4Ti(CH2SiMe3)2] (2) using a salt metathesis reaction. TiIV complex 1 was obtained by the reaction of the bis-borane ligand [{Ph2P(BH3)NH}2C6H4] and TiCl4 in toluene followed by the addition of 2 equivalents of [LiN(SiMe3)2] at ambient temperature. TiIV bis-alkyl complex 2 was isolated from the reaction of complex 1 with 2.5 equivalents of LiCH2SiMe3 in toluene. The solid-state structure of complex 1 is established by single-crystal X-ray diffraction analysis. TiIV bis-alkyl complex 2 has proved to be a competent catalyst in the deoxygenative reduction of aliphatic and aromatic esters with pinacolborane (HBpin) to afford corresponding boryl ethers at room temperature under solvent-free conditions. Catalyst 2 exhibits chemoselectivity toward ester functionalities over halides, heteroatoms, olefins, and amino functional groups. DFT studies demonstrate that the active form of catalyst 2 is capable of easily transferring its hydrides to ester substrates at room temperature. The studies further reveal that the rate-limiting step (RLS) in an ester-to-boryl ether conversion is the cleavage of the C-O bond of an ester. In brief, the titanium-catalysed ester-to-boryl ether conversions are found to be downhill processes having small activation barriers along all mechanistic steps. © 2022 The Royal Society of Chemistry.

In the field of air analysis, highlights within this review period included: a review paper of developments in new personal air samplers for workplace air measurements; a new passive air sampler for Hg0; new filter-based RMs; a new field-deployable carbon analyser for speciation measurements of carbonaceous aerosols and advances in the measurement of RCS using vibrational spectroscopic techniques. The maturity of AAS methods for the analysis of waters was highlighted this year by the lack of significant developments. All the novelty was in sample preparation as reflected in Tables 1 and 2. The tables also reflect the large interest in the use of graphene oxide as a solid phase for preconcentration and the continued use of magnetic nanoparticles. There are now enough methods and application to warrant the inclusion of the analysis of nanoparticles as a separate section rather than as a subsection in speciation. This trend is set to continue as instrumental improvements allow lower size LODs and the determination of lower particle numbers. Notable advances in the analysis of soils and plants included work on the preparation of new RMs as alternatives to NIST soil SRMs that are now in short supply. There was increased interest in the development of miniaturised AES instruments with the potential for field deployment. In the analysis of soil by LIBS, more studies included some form of external validation e.g. comparison with results of an established analytical method, which is most welcome. The availability of well-characterised matrix-matched reference materials continues to be a limitation in the production of high-quality geoanalytical data, particularly when exploring the fine structure of geological materials by microanalytical techniques such as LA-ICP-MS and SIMS. It is heartening to see that many of the researchers working in this area appreciate the importance of making new RMs available to the wider geochemical community. Although the development of portable

Coumaric acids and flavonoids play pivotal roles in protecting plants against ultraviolet radiation (UVR) exposure. In this work, we focus our photoprotection studies on p-coumaric acid and the flavonoid naringenin chalcone. Photoprotection is well-understood in p-coumaric acid; in contrast, information surrounding photoprotection in naringenin chalcone is lacking. Additionally, and vitally, how these two species work in unison to provide photoprotection across the UV-B and UV-A is unknown. Herein, we employ transient absorption spectroscopy together with steady-state irradiation studies to unravel the photoprotection mechanism of a solution of p-coumaric acid and naringenin chalcone. We find that the excited state dynamics of p-coumaric acid are significantly altered in the presence of naringenin chalcone. This finding concurs with quenching of the p-coumaric acid fluorescence with increasing concentration of naringenin chalcone. We propose a Fo¨rster energy transfer mechanism is operative via the formation of dipole–dipole interactions between p-coumaric acid and naringenin chalcone. To our knowledge, this is the first demonstration in plants of a synergic effect between two classes of phenolics to bypass the potentially damaging effects of UVR.

Herein we explore the opportunities arising from combining bicyclic amine cations with halometallate anions to build organic–inorganic hybrid materials. We will use the crystal engineering approach in these materials, focusing on the tuning of the organic cation, which is mainly responsible for obtaining both new plastic states at high temperature and electrical behaviour below the plastic temperature. Precisely, this work explores the influence of the ketonization of the bicyclic quinuclidine molecule (C7H13N)+, which, combined with the tetrachloroferrate(1-) anion, gives the compound (3-oxoquinuclidinium)[FeCl4]. Interestingly, crystallization in the presence of humidity is enough to obtain an isostructural hydrate phase of formula (3-oxoquinuclidinium)[FeCl4]·H2O. Although the organic–inorganic layered structure is the same in both compounds, the three-dimensional magnetic ordering disappears after the intercalation of crystallization water molecules. A heat treatment above 400 K allows the removal of water obtaining the non-hydrate phase. Finally, the temperature evolution of the electric and magnetic behaviour will be compared with other previously reported hybrid organic–inorganic materials built with tetrachloroferrate ions and quinuclidinium-based cations.