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We analyze schemes of high-fidelity multi-qubit CNOT N and C 2 NOT 2 gates for alkali metal neutral atoms used as qubits. These schemes are based on the electromagnetically induced transparency and Rydberg blockade. The fidelity of homonuclear multi-qubit CNOT N gate based on Rydberg blockade was limited by the undesirable interaction between the target atoms and by the coupling laser intensity. We propose overcoming these limits by using strong heteronuclear dipole–dipole interactions via Förster resonances for control and target atoms, while the target atoms are coupled by a weaker van der Waals interaction. We optimized the gate performance in order to achieve higher fidelity, while keeping the coupling laser intensity as small as possible in order to improve the experimental feasibility of the gate schemes. We also considered the optimization of the schemes of the C 2 NOT 2 gates, where the fidelity is affected by the relation between the control–control, control–target and target–target interaction energies. Our numeric simulations confirm that the fidelity of the CNOT 4 gate (single control and four target atoms) can be up to 99.3% and the fidelity of the C 2 NOT 2 (two control and two target atoms) is up to 99.7% for the conditions which are experimentally feasible. [ABSTRACT FROM AUTHOR]

We analyze schemes of high-fidelity multi-qubit CNOTN and C2NOT2 gates for alkali metal neutral atoms used as qubits. These schemes are based on the electromagnetically induced transparency and Rydberg blockade. The fidelity of homonuclear multi-qubit CNOTN gate based on Rydberg blockade was limited by the undesirable interaction between the target atoms and by the coupling laser intensity. We propose overcoming these limits by using strong heteronuclear dipole–dipole interactions via Förster resonances for control and target atoms, while the target atoms are coupled by a weaker van der Waals interaction. We optimized the gate performance in order to achieve higher fidelity, while keeping the coupling laser intensity as small as possible in order to improve the experimental feasibility of the gate schemes. We also considered the optimization of the schemes of the C2NOT2 gates, where the fidelity is affected by the relation between the control–control, control–target and target–target interaction energies. Our numeric simulations confirm that the fidelity of the CNOT4 gate (single control and four target atoms) can be up to 99.3% and the fidelity of the C2NOT2 (two control and two target atoms) is up to 99.7% for the conditions which are experimentally feasible.

The readily synthesized 3-(4-Hydroxy-1-methyl-1,2-dihydro-2-oxoquinolin-3-yl)-1-phenyl-1H-pyrazole-4-carbaldehyd (5) and 3-(2-Oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde (6) were utilized as a convenient starting precursor materials for synthesis of novel enone system 4-hydroxy-1-methyl-3-(4-(2H-2-oxo-chromen-3-yl)prop-2-enoyl)-1-phenyl-1H-pyrazol-4-yl)quinolin-2(1H)-one (7) and4-hydroxy-1-methyl-3-(2E)-3-(3-(2-oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazol-4-yl)acryloyl)quinolin-2(1H)-one (8). Simple homonuclear NOE experiment (NOESY 1D) method was performed for structure elucidation of the novel quinolinyl chalcones. The synthesized compounds have been estimated for their effect of growth on some selective crop of plants (Hibiscus, Mint and Basil).

Symmetrical NMR spectroscopy, such as Total Correlation Spectroscopy (TOCSY) and other homonuclear spectroscopy, displays symmetry in chemical shift but are generally not symmetrical in terms of intensity, which constitutes a pivotal branch of multidimensional NMR spectroscopy and offers a robust tool for elucidating the structures and dynamics of complex samples, particularly in the context of biological macromolecules. Non-Uniform Sampling (NUS) stands as a critical technique for accelerating multidimensional NMR experiments. However, symmetrical NMR spectroscopy inherently presents dynamic peak intensities, where cross peaks tend to be substantially weaker compared to diagonal peaks. Recovering these weaker cross peaks from NUS data poses a significant challenge, often resulting in compromised data quality. We enhance the reconstruction quality of NUS symmetrical NMR spectroscopy based on the assumption that the asymmetry in intensity is mild. Regarding the sampling schedule, we employ the symmetrical sampling structure integrated with Poisson sampling schedule to enhance the efficiency of data acquisition. In term of the reconstruction algorithm, we propose the new method by incorporating hard and soft symmetrical constraints into our recently developed L 1 -norm-based Compressed Sensing (CS) method known as Sparse Complex-valued REconstruction Enabled by Newton method (SCREEN). Additionally, we propose a two-step reconstruction strategy that separately addresses diagonal and cross peaks. In this two-step strategy, cross peaks are effectively reconstructed by excluding the stronger diagonal peaks. Extensive experimental results validate the effectiveness of our proposed methodology. This method enhances the overall quality of the reconstructed NUS symmetrical NMR spectra, especially in terms of cross peaks, thereby enriching the interpretation of spectral information. Furthermore, it boosts the robustness towards regularization parameters, facilitating a user-friendly experience. [Display omitted] • Symmetrical NMR spectroscopy provides powerful biochemical analysis. • Cross peak quality of NUS symmetrical NMR spectroscopy is improved with sampling schedule and reconstruction algorithm. • Symmetrical distribution is integrated into Poisson Sampling. • Symmetrical constraint and two-step strategy are employed in basis of CS methods. • Open-source software is attached for benefiting research community. [ABSTRACT FROM AUTHOR]

The readily synthesized 3-(4-Hydroxy-1-methyl-1,2-dihydro-2-oxoquinolin-3-yl)-1-phenyl-1 H -pyrazole-4-carbaldehyd (5) and 3-(2-Oxo-2 H -chromen-3-yl)-1-phenyl-1 H -pyrazole-4-carbaldehyde (6) were utilized as a convenient starting precursor materials for synthesis of novel enone system 4-hydroxy-1-methyl-3-(4-(2 H -2-oxo-chromen-3-yl)prop-2-enoyl)-1-phenyl-1 H -pyrazol-4-yl)quinolin-2(1 H)-one (7) and4-hydroxy-1-methyl-3-(2 E)-3-(3-(2-oxo-2 H -chromen-3-yl)-1-phenyl-1 H -pyrazol-4-yl)acryloyl)quinolin-2(1 H)-one (8). Simple homonuclear NOE experiment (NOESY 1D) method was performed for structure elucidation of the novel quinolinyl chalcones. The synthesized compounds have been estimated for their effect of growth on some selective crop of plants (Hibiscus, Mint and Basil). [ABSTRACT FROM AUTHOR]

Organometallic compounds are increasingly recognized as promising anticancer and antibiotic drug candidates. Among the transition metal ions investigated for these purposes, rhenium occupies a special role. Its tri- and dicarbonyl complexes, in particular, attract continuous attention due to their relative ease of preparation, stability and unique photophysical and luminescent properties that allow the combination of diagnostic and therapeutic purposes, thereby permitting, e.g., molecules to be tracked within cells. In this review, we discuss the anticancer and antibiotic properties of rhenium tri- and dicarbonyl complexes described in the last seven years, mainly in terms of their structural variations and in vitro efficacy. Given the abundant literature available, the focus is initially directed on tricarbonyl complexes of rhenium. Dicarbonyl species of the metal ion, which are slowly gaining momentum, are discussed in the second part in terms of future perspective for the possible developments in the field.

A series of novel homonuclear and heteronuclear bis-isatin derivatives tethered through ethylene were designed, synthesized and evaluated for their in vitro anti-mycobacterial activities against MTB H37Rv and MDR-TB. All hybrids exhibited potential anti-mycobacterial activities against MTB H37Rv and MDR-TB with MIC ranging from 16 to 256 μg/mL. In particular, the heteronuclear bis-isatin 4i (MIC: 25 and 16 μg/mL) was most active against MTB H37Rv and MDR-TB strains, and could act as a lead for further optimization. [ABSTRACT FROM AUTHOR]

Two lanthanide complexes are achieved by utilizing H 2 salen/acac ligands (H 2 salen = N , N′ -ethylenebis(salicylideneimine), acac = acetylacetonate). They are homonuclear [Nd 4 ( μ 3 -OH) 2 (salen) 2 (acac) 6 (CH 3 OH) 2 ]·CH 3 OH ( 1 ) and heteronuclear [NdYb(salen) 2 (acac) 2 ] ( 2 ). The structures of the two complexes were determined by X-ray crystallographic studies and their photophysical properties were investigated. The homonuclear Nd 4 complex exhibits characteristic metal-centered NIR emission. The heteronuclear NdYb shows ‘dual emission’ from both neodymium(III) and ytterbium(III) ions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cancer making it the second most leading cause of death after cardiovascular diseases. • Though many platinum-based drugs are currently being used widely in anticancer therapy, the therapeutic value of these complexes comes with severe side effects. • Thus, a tremendous amount of research is being carried out on the anticancer activity of other metal complexes to explore their anticancer activity. • Herein, we discuss the study of cellular uptake, localisation, mechanism of action and cytotoxicity profiles of several mononuclear and multinuclear ruthenium, iridium and rhenium complexes as potential chemotherapeutic agents. More than 10 million death tolls in 2020 were reported as a result of heinous impact of cancer, making it second most prime cause of death after cardiovascular diseases. In annihilation of cancer, many platinum-based drugs are currently being applied in anticancer therapy but the therapeutic value of these complexes comes with severe side effects. Hence, a profound research is needed to develop more selective and target specific chemotherapeutics so as to diminish the side effects. In this scenario, the anticancer activity of ruthenium, iridium and rhenium-based complexes have shown a light of hope for being explored as anticancer metallotherapeutics. This present review article, therefore, delineates the study of cellular uptake, localisation, mechanism of action and cytotoxicity profiles of several mononuclear and multinuclear ruthenium, iridium and rhenium complexes as target specific potential chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

In this article solid-state NMR methods for the determination of internuclear dipole–dipole couplings between homonuclear spin-1/2 nuclei are presented. They are suitable for relatively dense dipolar networks which are still dominated by 2-spin interactions. C-/R-symmetry theory is applied to create a double-quantum average Hamiltonian using phase-modulated radio-frequency irradiation and magic-angle sample-rotation. Symmetry derived pulse sequences with improved compensation against chemical shift anisotropies were found assuming a small isotropic chemical shift difference and using numerical calculations of the spin dynamics. Moreover it is shown that a constant time procedure can be used to acquire reliable double-quantum build-up curves even in systems in which damping obscures oscillations in their symmetric build-up curve. This technique is demonstrated on four crystalline model compounds with 31P and 13C spin systems typical for inorganic and biological applications. Comparison to crystal structure data indicates that the distances derived this way from 31P and 13C double-quantum NMR carry only small systematic errors caused for example by anisotropic J-coupling, dipolar contributions from adjacent spins and relaxation. [Copyright &y& Elsevier]

Spin-state selection in solid-state NMR is demonstrated, using similar pulse sequences as used in liquid-state NMR. The different transitions of all three carbon resonances in fully 13C-labeled l-alanine are separated in different spectra. By selecting spin-states, the contribution of the J-coupling to the linewidth is removed, leading to a considerable enhancement in resolution. The spin-state-selective technique is demonstrated for magic-angle spinning frequencies from 6 to 35 kHz. Other experimental conditions affecting the sensitivity of the experiments are discussed. Sensitivity losses due to the introduction of the spin-state-selective filter are shown to be acceptable. Finally, spin-state selection was used to experimentally confirm the differential broadening expected for the two transitions of the CH3 resonance. [Copyright &y& Elsevier]

Organometallic compounds are increasingly recognized as promising anticancer and antibiotic drug candidates. Among the transition metal ions investigated for these purposes, rhenium occupies a special role. Its tri- and dicarbonyl complexes, in particular, attract continuous attention due to their relative ease of preparation, stability and unique photophysical and luminescent properties that allow the combination of diagnostic and therapeutic purposes, thereby permitting, e.g., molecules to be tracked within cells. In this review, we discuss the anticancer and antibiotic properties of rhenium tri- and dicarbonyl complexes described in the last seven years, mainly in terms of their structural variations and in vitro efficacy. Given the abundant literature available, the focus is initially directed on tricarbonyl complexes of rhenium. Dicarbonyl species of the metal ion, which are slowly gaining momentum, are discussed in the second part in terms of future perspective for the possible developments in the field. [ABSTRACT FROM AUTHOR]

The subject RNA models the binding site for the coat protein of the R17 virus, as well as the ribosome recognition sequence for the R17 replicase gene. With an RNA of this size, overlaps among the sugar protons complicate assignments of the 1H NMR spectrum. The cross peaks that overlap significantly in 2D-NOE spectra can frequently be resolved by introducing a third, in our approach the double-quantum, frequency axis. In particular the planes in a 3D-NOE/2QC spectrum perpendicular to the 2Q axis are extremely useful, showing a highly informative repeating NOE-2Q pattern. In this experiment substantial J-coupling confers special advantages. This always occurs for geminal pairs (H5′/H5′′ for RNA plus H2′/H2′′ for DNA), as well as for H5/H6, for H3′/H4′ in sugars with substantial populations of the N-pucker, for H1′/H2′ for S-puckered sugars, and usually for H2′/H3′. For the 24-mer RNA hairpin the additional information from the 3D-NOE/2QC spectrum allowed assignment of all of the non-exchangeable protons, eliminating the need for stable-isotope labeling. [ABSTRACT FROM AUTHOR]

Atomically dispersed metal catalysts with well-defined structures have been the research hotspot in heterogeneous catalysis because of their high atomic utilization efficiency, outstanding activity, and selectivity. Dual-atomic-site catalysts (DASCs), as an extension of single-atom catalysts (SACs), have recently drawn surging attention. The DASCs possess higher metal loading, more sophisticated and flexible active sites, offering more chance for achieving better catalytic performance, compared with SACs. In this review, recent advances on how to design new DASCs for enhancing energy catalysis will be highlighted. It will start with the classification of marriage of two kinds of single-atom active sites, homonuclear DASCs and heteronuclear DASCs according to the configuration of active sites. Then, the state-of-the-art characterization techniques for DASCs will be discussed. Different synthetic methods and catalytic applications of the DASCs in various reactions, including oxygen reduction reaction, carbon dioxide reduction reaction, carbon monoxide oxidation reaction, and others will be followed. Finally, the major challenges and perspectives of DASCs will be provided., (© 2021 Wiley-VCH GmbH.)

The choices of Na+ ions appear to play a fundamental role in determining the final structure. Electrospray-ionization mass spectrometry (ESI-MS) demonstrates that complex 1 shows a more complicated change in the solution. For the complex 2 , the species change in different solutions is relatively small due to its high stability of the cluster core. The organic ligand (E)-8-hydroxyquinoline-2-carbaldehyde oxime (H 2 L) was used to react with Ni(CH 3 COO) 2 ·4H 2 O and NaN(CN) 2 at 100 °C to obtain the complex [Ni 3 Na(HL) 3 (L) 2 ] n ·4nCH 3 CN (1). Interestingly, the five ligands in the structure chelate three Ni ions, and the uncoordinated O on the ligand captures one Na+. However, the above scheme remains the same, and after adding isonicotinic acid (ina), it obtained the complex [Ni 4 (HL) 4 (L) 2 ] 2 ·2CH 3 CN (2), which eight Ni2+ ions are coordinated by twelve ligands. The component distribution of the complexes in different solutions was measured by electrospray-ionization mass spectrometry (ESI-MS). It was found that the complexes exhibited different component distribution in different solutions. Not only the existence of low-nuclear molecular ion peaks could be monitored, but even higher-nuclear components could also be detected, and the alkali metal ions could be effectively identified. It was indicating that the compounds would assemble differently in different solutions. Surprisingly, homonuclear clusters 2 was providing a basis for further directing the directed synthesis of higher nuclear clusters. [ABSTRACT FROM AUTHOR]