Phosphorous Atoms Research Articles

Expanding the Landscape of Phosphorous-Based Open Shell Species: Stable Mono-, Di-, and Trianionic Radicals Based on a Contorted Triphosphaalkene.

The stepwise reduction of the highly contorted truxene-based triphosphaalkene 1 using KC8 led to the isolation of mono-, di-and tri-anionic species. The solid-state molecular structures of mono- and diradical anionic species were elucidated by single crystal X-ray diffractions, revealing elongated P-C bonds and a pronounced "indene" aromatization compared to the parent system. All three radical species displayed distinct Electron Paramagnetic Resonance (EPR) spectra, providing compelling evidence for the open-shell electronic configuration of both the diradical and triradical species-an observation unprecedented in any previously reported phosphorous-based anionic polyradicals. Mulliken spin density calculations revealed a dominant localization of radical spin on a single phosphorous atom in the monoanion. In the dianion, spin localization is observed on two phosphorous atoms (~34% each), with a minor contribution from the third phosphorous (0.13%), while the trianion demonstrates a uniform distribution of spin density (~30%) across each phosphorous atom.

Photoluminescence of dense arrays of InGaPAs/InGaAs quantum dots formed by substitution of group V elements

One drawback of self-organized quantum dots is their low optical gain. The development of new shaping methods that would allow higher gain, for example, due to a higher surface density of the QD array, remains an important task to date. In the present work, arrays of quantum dots have been formed by substituting phosphorous atoms with arsenic ones in a thin InGaP epilayer. Based on transmission electron microscopy data, the surface density was estimated to be about 1.3 × 1012 cm−2, which is one of the highest values for quantum dots on GaAs. The influence of an additional InGaAs epilayer (quantum well) on the luminescence properties of quantum dots was investigated in a wide temperature range and different optical pumping levels. It was found that placing the quantum well under the layer of quantum dots has little effect on the central emission wavelength, while quantum dots covered with the InGaAs demonstrate a strong red shift of the luminescence spectrum. A transition from a nonequilibrium to an equilibrium distribution of charge carriers over quantum-dot states, related to the lateral transport of charge carriers over quantum dot array, similar to that previously observed in In(Ga)As Stranski-Krastanow quantum dots, was revealed. This is manifested in a change in temperature dependencies of the linewidth and peak position of the photoluminescence band. For the structures under study, this transition occurs at a temperature of about 125 K. Rapid thermal annealing of the structures allows to increase the integrated photoluminescence intensity of quantum dots up to 4 times, while the maximum of the spectrum remains almost unchanged, provided that the annealing temperature does not exceed 620 °C.

Tailored portable electrochemical sensor for dopamine detection in human fluids using heteroatom-doped three-dimensional g-C3N4 hornet nest structure

BackgroundThere is widespread interest in the design of portable electrochemical sensors for the selective monitoring of biomolecules. Dopamine (DA) is one of the neurotransmitter molecules that play a key role in the monitoring of some neuronal disorders such as Alzheimer's and Parkinson's diseases. Facile synthesis of the highly active surface interface to design a portable electrochemical sensor for the sensitive and selective monitoring of biomolecules (i.e., DA) in its resources such as human fluids is highly required. ResultsThe designed sensor is based on a three-dimensional phosphorous and sulfur resembling a g-C3N4 hornet's nest (3D-PS-doped CNHN). The morphological structure of 3D-PS-doped CNHN features multi-open gates and numerous vacant voids, presenting a novel design reminiscent of a hornet's nest. The outer surface exhibits a heterogeneous structure with a wave orientation and rough surface texture. Each gate structure takes on a hexagonal shape with a wall size of approximately 100 nm. These structural characteristics, including high surface area and hierarchical design, facilitate the diffusion of electrolytes and enhance the binding and high loading of DA molecules on both inner and outer surfaces. The multifunctional nature of g-C3N4, incorporating phosphorous and sulfur atoms, contributes to a versatile surface that improves DA binding. Additionally, the phosphate and sulfate groups' functionalities enhance sensing properties, thereby outlining selectivity. The resulting portable 3D-PS-doped CNHN sensor demonstrates high sensitivity with a low limit of detection (7.8 nM) and a broad linear range spanning from 10 to 500 nM. SignificanceThe portable DA sensor based on the 3D-PS-doped CNHN/SPCE exhibits excellent recovery of DA molecules in human fluids, such as human serum and urine samples, demonstrating high stability and good reproducibility. The designed portable DA sensor could find utility in the detection of DA in clinical samples, showcasing its potential for practical applications in medical settings.

Structural modification of graphene material by silicon mono-doping and codoping with heteroatoms as sensors for methyl tert-butyl ether (MTBE) as a fuel additive: Insights from DFT

Due to the association of methyl tert-butyl ether (MTBE) with groundwater contamination and environmental concerns, fuel additives, and recognized health hazards, including respiratory and central nervous system effects upon exposure, the implementation of mitigating measures becomes imperative on a global scale, particularly through the utilization of nano-oriented materials. Hence, to account for the sensitivity, detection, and adsorption of methyl tert-butyl ether (MTBE) pollutants, this research attempts to investigate the potential of silicon-doped graphene (Si@GP) engineered with boron, nitrogen, and phosphorous atoms by employing density functional groups at the ωB97XD/def2vsp level of theory. Interestingly, the results from several quantum descriptors were analysed to obtain comprehensive knowledge of the interactions between the adsorption complexes. The examined systems (MTBE-Si@GP, MTBE-SiB-GP, MTBE-SiN-GP, and MTBE-SiP-GP) produced Fermi energies of 0.4531 eV, 0.4531 eV, 0.5274 eV, and 0.3936 eV, respectively, providing valuable insights into their electronic structure and sensitivity to MTBE. Subsequent calculations revealed that MTBE-SiP-GP had a work function of 0.3936 eV, making it a superior surface for sensing MTBE compared to the other surfaces considered. The adsorption energies for MTBE-Si@GP, MTBE-SiB-GP, MTBE-SiN-GP, and MTBE-SiP-GP were 8.004 eV, 7.159 eV, 7.785 eV, and 5.027 eV, respectively. Despite their physisorption properties, MTBE-SiP-GP was highlighted as the preferable absorbent at the BSSE level. The comprehensive analysis presented in this study highlights the potential of the MTBE-SiP-GP dopant as a reliable sensing material for monitoring MTBE liquified gas in real-world environments. Our research aims to equip experimental researchers with valuable insights on the silver graphene dopant, and specifically, the MTBE-SiP-GP surface, as a promising candidate for detecting gas sensors.

Valuable insights into the structural, electronic, and aromaticity aspects of azulene and its monophospha-derivatives

Azulene-based conjugated systems have garnered considerable interest owing to their atypical structures. The incorporation of a phosphorous atom into the azulene framework offers an enticing prospect for the creation of unique organophosphorous π-conjugated compounds. No such phosphaazulene skeleton however has been reported to date. Here, density functional theory calculations were employed to examine the physicochemical properties and aromaticity of azulene and its monophospha-derivatives. The electronic, magnetic, and structural properties were taken into consideration. The reactivity of azulene and its monophospha-analogs including 1-phospha (1p), 2-phospha (2p), 4-phospha (3p), 5-phospha (4p), and 6-phosphaazulene (5p), was examined through local electrophilicity and local nucleophilicity indices. The stability and aromaticity of these compounds were determined using DFT calculations with the B3LYP/6–311 + G(d,p) method. The stability of monophosphaazulene derivatives is significantly influenced by the position of the phosphorus atom, as indicated by the energy calculations. The order of stability was found to be 1p > 2p > 5p > 3p > 4p. Aromaticity studies based on HOMA, ΔBl, FLUπ, SA, and NICS indices indicated that the incorporation of a phosphorus atom into the 5-membered ring decreased its aromaticity while simultaneously increasing the aromaticity of the 7-membered ring. However, replacing the carbon atom with phosphorus atom in the 7-membered ring reduced the aromaticity of both rings. Additionally, the ability of π-stacking, as determined by the LOLIPOP criterion, was reduced in the monophosphaazulene derivatives compared to azulene, except for compound 5p. The order of π-stacking ability was 5p > azulene > 2p > 1p > 4p > 3p. Overall, there was a good agreement between the various aromaticity indices, providing consistent results for both rings in azulene and monophosphaazulenes.

Schwesinger Bases – Phosphazene Bases Stabilized by Multiple Counterpoise Hyperconjugative Interactions

AbstractElectronic structure and proton affinity of Schwesinger bases (Pn bases where n=1–4 indicates the number of phosphorous atoms) were studied using quantum mechanical calculations carried out at M06/def2‐TZVPP//BP86‐D3(BJ)/def2‐TZVPP level of theory. Each phosphorous atom is in the ligating environment of four tricoordinated/dicoordinated nitrogen atoms having one/two lone pairs. While the lone pairs on the tricoordinated/dicoordinated nitrogen atoms act as hyperconjugative donors, the P−N σ* orbitals act as hyperconjugative acceptors. These phosphazene bases are highly stabilized by synergetic hyperconjugative interactions which can accordingly be termed as counterpoise hyperconjugation. The number and the extent of pseudo‐π‐delocalization resulting from hyperconjugative interactions get enhanced as P1 changes to P4. Moreover, additional pseudo‐π‐delocalization starts to appear as P1 changes to P4. The phosphazene P2 has one Ndi(σ)−P−Ndi(σ)−P pseudo‐π‐delocalization which is similar to that of classical π‐delocalization in 1,3‐butadiene. On the other hand, phosphazene P3 has two pseudo‐π‐delocalization similar to that of 1,3‐butadiene and one pseudo‐π‐delocalization similar to that of 1,3‐pentadienyl cation. There are three pseudo‐π‐delocalization similar to that of 1,3‐butadiene and another three pseudo‐π‐delocalization similar to that in 1,3‐pentadienyl cation in P4. Consequently, pseudo‐π‐delocalization is present in all the tetrahedral symmetry planes of P4. Hence, P4 can be considered as a three‐dimensional pseudo‐π delocalized system. Even though the lone pair orbitals are stabilized by hyperconjugative interactions, they are susceptible to protonation. Among the dicoordinated and tricoordinated nitrogen atoms, the proton affinity of the dicoordinated nitrogen atom connected to the tBu group is much higher (257.4 kcal/mol–291.6 kcal/mol), and the proton affinity values increase on going from P1 to P4. The very high proton affinity of this dicoordinated nitrogen atom indicates its superbasic character.

Atomic ordered doping leads to enhanced sensitivity of phosgene gas detection in graphene nanoribbon: a quantum DFT approach

We explore a novel sensor for detection of phosgene gas by graphene derivatives such as pristine and doped graphene nanoribbons via first principles calculations. The interaction of phosgene molecule with various edge and center doped configurations of boron, phosphorus and boron-phosphorus co-doped armchair graphene nanoribbon (AGNR) and zigzag graphene nanoribbon (ZGNR) is investigated through density functional theory (DFT). P-doped systems showcase chemisorption, displaying enhanced sensitivity to phosgene detection as reflected by a more negative adsorption energy values, accompanied by a prominent charge transfer due to the doping. Regardless of nanoribbon geometry, the binding energies of P-doped systems exhibit notable uniformity within the range of −8.01 eV to −8.49 eV, however the adsorption energies in ZGNR are significantly lower than those observed in AGNR. Due to much higher(lower) electron-donating (accepting) capacity of phosphorous(boron) atoms in comparison to ‘C’ atom, substitutional doping with ‘P’ or ‘B’ atoms in AGNR has signifiant impact on the structural, electronic and adsorption properties of the nanoribbons. We observe that phosphorus doped configurations (edge/center) effectively interact with phosgene molecule with higher adsorption that corresponds to the chemisorption phenomenon. The strongest adsorption energy (−8.83 eV) is obtained for P doped configurations, followed by that for B+P co-doped AGNR (−4.23 eV). These results suggest significantly stronger adsorption of phosgene gas on P doped AGNR than on any other systems reported so far. Band structure analysis estimates that by phosphorus doping, changes in the band gap is significant and it also shows prominent changes in the band structures. Isosurface electronic charge density plots identify that the transfer of charge takes place from graphene system to phosgene molecule. Thus, significant variation in adsorption and electronic properties of P doped AGNR reveal that these geometries immensely promote the detection of phosgene gas, and may be considered as promising chemical sensor for phosgene removal.

Novel ternary Zintl phosphide halides Ba3P5X (X = Cl, Br) with 1D helical phosphorus chains: synthesis, crystal and electronic structure.

Black single crystals of two novel ternary phosphide halides, Ba3P5Cl and Ba3P5Br, were grown using molten metal Pb-flux high-temperature reactions. These compounds were structurally characterized with the aid of the single-crystal X-ray diffraction (SCXRD) method at 100(2) K. The SCXRD shows that both compounds are isostructural and adopt a new structure type (space group R3̄c, No. 167, Z = 6) with unit cell parameters a = 14.9481(16) Å, c = 7.3954(11) Å and a = 15.045(4) Å, c = 7.537(3) Å for Ba3P5Cl and Ba3P5Br, respectively. Cl- and Br- anions are octahedrally coordinated by Ba2+ cations, thus composing a face-sharing 1D infinite chain 1∞[XBa3]5+ running along the [001] direction. Moreover, the crystal structures feature peculiar one-dimensional disordered infinite helical chains of 1∞P-, composed of partially occupied phosphorous atoms, each being a superposition of three symmetrical copies of the ordered phosphorus chain, with continuity along the c-axis. Ba3P5X (X = Cl, Br) compounds are charge-balanced heteroanionic Zintl phases according to the charge-partitioning scheme (Ba2+)3[P-]5X-. The presumed semiconducting behavior of both compounds corroborates well with the results of the electronic structure calculations performed with the aid of the TB-LMTO-ASA code.

Inhibition of DXR in the MEP pathway with lipophilic N-alkoxyaryl FR900098 analogs.

In Mycobacterium tuberculosis (Mtb) and Plasmodium falciparum (Pf), the methylerythritol phosphate (MEP) pathway is responsible for isoprene synthesis. This pathway and its products are vital to bacterial/parasitic metabolism and survival, and represent an attractive set of drug targets due to their essentiality in these pathogens but absence in humans. The second step in the MEP pathway is the conversion of 1-deoxy-d-xylulose-5-phosphate (DXP) to MEP and is catalyzed by 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR). Natural products fosmidomycin and FR900098 inhibit DXR, but are too polar to reach the desired target inside some cells, such as Mtb. Synthesized FR900098 analogs with lipophilic substitution in the position α to the phosphorous atom showed promise, resulting in increased activity against Mtb and Pf. Here, an α substitution, consisting of a 3,4-dichlorophenyl substituent, in combination with various O-linked alkylaryl substituents on the hydroxamate moiety is utilized in the synthesis of a novel series of FR900098 analogs. The purpose of the O-linked alkylaryl substituents is to further enhance DXR inhibition by extending the structure into the adjacent NADPH binding pocket, blocking the binding of both DXP and NADPH. Of the initial O-linked alkylaryl substituted analogs, compound 6e showed most potent activity against Pf parasites at 3.60 μM. Additional compounds varying the phenyl ring of 6e were synthesized. The most potent phosphonic acids, 6l and 6n, display nM activity against PfDXR and low μM activity against Pf parasites. Prodrugs of these compounds were less effective against Pf parasites but showed modest activity against Mtb cells. Data from this series of compounds suggests that this combination of substituents can be advantageous in designing a new generation of antimicrobials.

Li2s-PI3 Cathode for High-Energy-Density All-Solid-State Lithium-Sulfur Batteries

1.Introduction All-solid-state lithium-sulfur batteries (ASSLSBs) are one of the most promising next-generation large scale energy storage devices due to their remarkably high theoretical energy density, which is generated by high capacity of both cathodes, like element S or Li2S and Li metal anode. However, due to insufficient electronic and/or ionic conductivities of element S and Li2S, the low sulfur utilization and correspondingly unsatisfied practical energy density hinder the application of ASSLSBs largely. By heterovalent doping, vacancies in Li2S could be created, leading to higher ionic conductivity [1-2]. In this study, we developed different proportion of PI3-doping Li2S as active material to improve the sulfur utilization. Mixing with CNovel as electronic additive, Li2S-PI3-CNovel as cathode material shows good electrochemical performance. In order to clarify the effect of doping PI3, a detailed analysis of the point defect structure was performed using pair distribution function analysis using high-energy X-ray diffraction, synchrotron X-ray diffraction measurements, and X-ray absorption measurements to correlate with the electrochemical properties. 2. Experimental Li2S-PI3 as active material was synthesized by mixing Li2S and PI3 as raw materials with ball milling method and the proportion of raw materials has been optimized. The characterization of the prepared Li2S-PI3 was conducted by Synchrotron XRD coupled with pair Distribution Function analysis. The ionic conductivities were measured by AC impedance. The cathode materials were prepared based on active materials (90 wt%) and CNovel (10 wt%) as electronic conductor. The batteries composed of Li2S-PI3-CNovel as cathode, Li3PS4 as SSE and Li-In alloy as anode were assembled in the glove box filled with Ar atmosphere. The charge-discharge curves were obtained by galvanostatic measurement. The electronic structure and morphology of the Li2S-PI3-CNovel after electrochemical measurements were examined by X-ray Absorption Spectroscopy (XAS) for S K-edge, P K-edge, and I K-edge. 3.Results and Discussion Pair distribution function (PDF) analysis revealed that with PI3 doping, iodine atoms would occupy sulfur sites and phosphorous atoms would occupy lithium sites, creating lithium vacancies in the antifluorite structure. Figure 1 shows the charge/discharge curves of the Li2S-PI3-CNovel as cathode. The Li2S-PI3-CNovel cathode shows a charge capacity of 440 mAh g-1 and a discharge capacity of 494 mAh g-1 in the first cycle. And the capacities increase to 538 mAh g-1 during the subsequent cycles, with an average voltage of 1.81 V (vs Li/Li+). Even at 1 C (1 C=626 mAh g-1), the cathode without solid-state electrolyte could deliver 207 mAh g-1, corresponding to 38 % capacity retention of that at 0.05 C, which demonstrates good rate performance (Figure 2). The charge compensation is attributed to S, suggesting the conversion reaction between Li2S and element S, which was confirmed by XAS for S K-edge and P K-edge. References H Gamo.et al., Adv. 2022, 3, 2488-2494.NHH Phuc. et al., Energy Res., 2021, 8, 606023. Acknowledgement This research was financially supported by JST ALCA-SPRING Project. Figure 1

Inquest for the interaction of canonical and non-canonical DNA/RNA bases with ternary based 2D Si2BN and doped Si2BN for biosensing applications

Density functional theory (DFT) is invoked to investigate the interaction between the canonical (CN) and non-canonical (NC) bases with pristine Si2BN (Si2BN) and Phosphorous-doped Si2BN (P-dop-Si2BN) sheets. Inquest for the better sensing substrate is decided through the adsorption energy calculation which reveals that doping of phosphorous atom enhances the adsorption strength of AT (-83.74 kcal/mol) AU (-82.77 kcal/mol) and GC (-96.36 kcal/mol) base pairs. The CN and NC bases have higher adsorption energy than the previous reported values which concludes that the P-dop-Si2BN sheet will be optimal substrate to sense the bases. Meanwhile, the selected CN and NC (except hypoxanthine) bases interact with sheet in parallel manner which infers the π-π interaction with Si2BN and P-dop-Si2BN sheets. The energy gap variation (ΔEg%) of the P-dop-Si2BN complexes has a noticeable change, ranging from −24.75 to −197.28% which thrust the sensitivity of the P-dop-Si2BN sheet over the detection of CN and NC bases. The natural population analysis (NPA) and electron density difference map (EDDM) confirms that charges are transferred from CN and NC bases to Si2BN and P-dop-Si2BN sheet. The optical property of the P-dop-Si2BN complexes reveals that the noticeable red and blue shift in the visible and near-infrared regions (778 nm to 1143 nm) has been observed. Therefore, the above results conclude that the P-dop-Si2BN sheet plays a potential candidate to detect the CN and NC bases which contribute to the development of biosensors and DNA/RNA sequencing devices. Communicated by Ramaswamy H. Sarma

Planar hexacoordinate phosphorous and arsenic

Here the first planar hexacoordinate phosphorous and arsenic (phP and phAs) atoms are reported. Neutral 18 valence electron EBe3Li3H6 clusters (E = P, As) adopt planar D3h symmetry in their lowest energy singlet state. Chemical bonding reveals partial double bond character in P(As)-Be bonds and single bond character in P(As)-Li bonds. Born-Oppenheimer molecular dynamics simulation as well as their reluctance towards decomposition reveals high kinetic stability of these clusters.

Development of a new vesicular formulation for delivery of Ifosfamide: Evidence from in vitro, in vivo, and in silico experiments

Ifosfamide (IFO) is a member of the oxazaphosphorine family of alkylating drugs that exhibits anticancer and immunoregulatory properties. The toxicity of IFO is dose-limited because of its biotransformation into highly reactive metabolites, including acrolein and chloroacetaldehyde. Here, we aimed to design novel niosomal formulations to encapsulate IFO within niosomes and assess the efficacy of the nanoformulation via conducting in vivo, in vitro, and in silico analyses. Niosomal IFO showed a monodisperse size distribution with an average size of 97 nm. In addition, transmission electron microscopy (TEM) revealed a spherical morphology with high stability and no aggregation. On the other hand, niosomal IFO (0.01–100 µg/mL) showed high cytotoxicity against breast cancer (MCF7) and neuroblastoma (SH-SY5Y) cells in a concentration-dependent fashion. IFO-loaded niosomes had lower IC50s in cancerous cell lines than the standard IFO, the most pronounced being in SH-SY5Y cells (IC50 = 0.184 µg/mL). Intravenous treatments of rats with niosomal IFO at 0.1 mg/kg body weight (bw) and 0.2 mg/kg bw significantly increased biochemical parameters such as blood urea nitrogen (BUN), creatinine (CR), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Moreover, the 0.2 mg/kg bw doses of niosomal IFO caused obvious changes in the liver tissue. Both 0.1 mg/kg bw and 0.2 mg/kg bw doses of free IFO caused histopathological lesions and significantly increased biochemical parameters. In silico calculations revealed the interaction of IFO through its oxygen and nitrogen connected to the phosphor atom and nitrogen with a head group of Span 60 and tween 60. For the first time, we designed a well-characterized niosomal formulation for the targeted delivery of IFO. Our formulation exhibited optimum size with desirable anticancer activity and can be considered a suitable carrier with a high potential for future usage in the controlled release of other chemotherapeutics; however, more studies are needed to assess its safety towards normal human cells.

Transparent and flexible photocatalytic film comprising organophosphonate-modified polysilsesquioxane-anchored titanium dioxide: hydroxy group ratio and organic substituent on phosphorous atoms

Transparent and flexible photocatalytic films have attracted considerable attention in recent years. We previously prepared a film with titanium dioxide (TiO2) and an anchor layer of phenylphosphonate-modified polysilsesquioxane (PhPPS-low), which had a phosphonate group and a phenyl substituent; this film exhibited transparency and flexibility. In this study, we reported the differences in the hydroxy group ratio on the phosphorous atoms and the presence or absence of phenylene moieties. Three organophosphonate-modified polysilsesquioxanes (APPS-low, APPS-high, and PhPPS-high) were synthesized. All photocatalytic films using APPS-high, APPS-low, and PhPPS-high exhibited photodegradation of methylene blue and photocatalytic bactericidal effects on Escherichia coli, and hydroxyl radical generation was confirmed. In particular, the photocatalytic film with PhPPS-high showed the highest photocatalytic ability.

Ni-single atom decorated mesoporous carbon electrocatalysts for hydrogen evolution reaction

A single atom catalyst (SAC) is a type of heterogeneous catalyst in which individual metal atoms are dispersed on a support material, such as carbon, metal oxides, or zeolites, rather than forming nanoparticles or clusters. SACs have unique catalytic properties, such as high selectivity and activity, due to their high surface area and the exposed active metal sites, allowing them to interact more efficiently with the reactants. SACs also have the advantage of being more environmentally friendly and cost-effective than traditional catalysts, as they require smaller amounts of metal and can be easily recycled. In this study, we report the synthetic method of mesoporous single atom catalysts (MSACs) containing nickel (Ni), platinum (Pt), iridium (Ir), cobalt (Co), and iron (Fe) as metal-centered atoms for hydrogen evolution reaction (HER). MSACs are successfully synthesized with metal-chelation and soft-templating methods. The results show that highly uniform MSACs can be fabricated with high reproducibility. The metal contents in MSACs can be reduced to under 1wt%, keeping good HER reactivity. For HER, the Ni mesoporous single atom catalysts (Ni-MSACs) show 270 mV overpotential at 10 mA/cm2 at the initial polarization curve and reduces to 190 mV after 2,000 cycles, which outperforms Ni bulk catalyst (Ni plate). In contrast, porous pure carbon without Ni atoms shows inferior performance, indicating that Ni metal center plays an important role in the catalytic activity. The computational calculation using density functional theory (DFT) tells that Volmer-Heyrovsky pathway is dominant for HER using the Ni-MSACs. The performance of MSACs has a high potential for improvement of performance and extreme reduction of metal usage by doping nitrogen, phosphorous, and two or more metal atoms into MSACs.

Organosilane as a versatile compound: Silica-Based nanoparticles for detection of methyl parathion and inhibition of acetylcholinesterase (AChE) in Alzheimer’s disease

In this article, we sketched and synthesized chalcone appended triazole organosilane (TP), and it was thoroughly characterised using NMR (1H and 13C) and mass spectrometry. Furthermore, TP was immobilized over the silica nanoparticles (TP-NPs) utilizing one-pot strategy, and TP-NPs were thoroughly characterised using various techniques including FT-IR, XRD, EDX, FE-SEM, and TGA. TP-NPs were found to be very sensitive and selective towards detection of methyl parathion (MP) over other tested ions by both UV–Visible and fluorescence spectroscopy, with values of limit of detection as low as 3.83 X 10−9 M and 5.76 X 10−10 M, respectively. TP-NPs has high surface area and have various functional group present on the surface which aid in the detection of MP; nitrogens of the triazole moiety have high affinity for phosphorous atom in MP while Si atom interacts with the oxygen present in the MP, facilitating the sensing of MP by TP-NPs. Additionally, in silico docking studies showed that TP exhibits a good inhibitory response to the human acetylcholinesterase (AChE) protein, making it a potential candidate against Alzheimer’s disease (AD). Also, the real sample analyses of methyl parathion in agricultural soil and water samples were successfully done with excellent recovery rates, ranging from 92.25% to 109%, respectively.

Synthesis of UHMWPE by neutral phosphine-phenolate based nickel catalysts

It is highly interesting to prepare polyethylene with ultra-high molecular weight under homogeneous conditions by nickel based neutral P^O type catalysts. In this contribution, ligand remote electronic effect was explored in some sterically hindered phosphine-phenolate based neutral nickel catalysts Ni1–Ni3 to afford UHMWPE. The maximal activity of these catalysts was found to be 1.33 × 106 g mol−1 h−1, which is quite active. The nickel catalysts retained considerable activity at high temperature of 120 °C showing their good thermal stability. More importantly, all these catalysts are capable of generating UHMWPE with maximum Mn of 2.51 × 106 g mol−1 by Ni2. The minimum distance between the Ni center and the oxygen of the 2,6-dimethoxy-1,1′-biphenyl unit attached with the phosphorous atom in Ni1 was recorded as 3.154 Å, which exactly matches with the van der Waals radii of oxygen and nickel. This provides an effective shield around the metal by preventing chain transfer and resulting to enhance the molecular weight of polymer. Combined with steric the remote substituents effect also crucial both to modulate activity and molecular weight of polymers.

Dispersive cavity-mediated quantum gate between driven dot-donor nuclear spins

Nuclear spins show exceptionally long coherence times but the underlying good isolation from their environment is a challenge when it comes to controlling nuclear spin qubits. A particular difficulty, not only for nuclear spin qubits, is the realization of two-qubit gates between distant qubits. Recently, strong coupling between an electron spin and microwave resonator photons as well as a microwave resonator mediated coupling between two electron spins both in the resonant and the dispersive regime have been reported and, thus, a microwave resonator mediated electron spin two-qubit gate seems to be in reach. Inspired by these findings, we theoretically investigate the interaction of a microwave resonator with a hybrid quantum dot-donor (QDD) system consisting of a gate-defined Si QD and a laterally displaced $^{31}\mathrm{P}$ phosphorous donor atom implanted in the Si host material. We find that driving the QDD system allows to compensate the frequency mismatch between the donor nuclear spin splitting in the MHz regime and typical superconducting resonator frequencies in the GHz regime, and also enables an effective nuclear spin-photon coupling. While we expect this coupling to be weak, we predict that coupling the nuclear spins of two distant QDD systems dispersively to the microwave resonator allows the implementation of a resonator-mediated nuclear spin two-qubit $\sqrt{i\mathrm{SWAP}}$ gate with a gate fidelity approaching $90%$.

Solid-phase synthesis and properties of stereocontrolled boranophosphate/phosphate and phosphorothioate/phosphate chimeric oligouridylates.

This study describes the stereoselective synthesis of boranophosphate/phosphate (PB/PO) and phosphorothioate/phosphate (PS/PO) chimeric oligouridylates using the solid-phase method. Oxazaphospholidine monomer was used to construct the stereodefined PB and PS linkages. The study introduces modifications to oligouridylate derivatives in the intended positions with the intended stereochemistry of phosphorous atoms. Additionally, biophysical and biochemical properties of the synthesized oligomers were evaluated. Notably, it was found that a (Sp)-PB/PO chimeric oligouridylate had higher hybridization ability than the unmodified counterpart to an unmodified oligoadenylate. This is the first report that elucidates the effect of both stereochemistry and type of P-modification (PB and PS) on properties of oligoribonucleotides.

The boron-phosphorous co-doping scheme for possible n-type diamond from first principles

In this paper, we have investigated a boron-phosphorous co-doping scheme in diamond bulk for the possibility of realizing n-type conductive diamond by first-principles calculations. A comprehensive searching of B-2P complexes (a complex consisting of one boron atom and two phosphorous atoms) with different configurations have been done. Results have shown that the B-2P complexes in various forms are donor-like and can be relatively easy to form. Especially for a specific configuration (P-C-B-C-P, B-2P complex in which the P and B atoms are separated by a carbon atom), the ionization energy is as low as 109 meV. Both the formation energy and the ionization energy (3.025 eV, 109 meV) are much lower than those for the single phosphorous impurity (7.85 eV, 414 meV). It is quite encouraging to discover this complex theoretically that can be a perfect candidate for shallow donor in diamond.