Dinuclear Research Articles

Surface-like NOx Reduction at an Atomically-Precise Tricopper Cluster.

The combustion of nitrogen-containing fuels and increasing use of nitrogen-rich fertilizers is accumulating NOx pollutants in the environment. Copper is an attractive catalyst material for reductive NOx remediation, yet ambiguity persists regarding the elementary bond-making and bond-breaking steps occurring at the catalyst interface. Starting from a molecular tricuprous µ3-oxo complex (1), an unusually reduced and highly reactive surface-like cluster (2) has been prepared. Characterization data and electronic structure calculations are consistent with 2 featuring σ-aromaticity that primes the tricopper core for two-electron chemistry. Cluster 2 mediates catalytic reductive coupling of NO to N2, proceeding through N2O,via sequential oxygen atom transfer steps. Stoichiometric reduction of NO3- and NO2- is also disclosed, mapping the complete denitrification cycle at an atomically-precise molecular cluster.

Occupancy Determination from Resonant X-ray Diffraction.

We analyze the effect of integrated resolution, data scaling, structural refinement, and crystal symmetry on the extracted scattering perturbations and their uncertainties for anomalous (resonant) X-ray diffraction on mixed-metal molecular clusters. We probe the metal constituency, substitutional homogeneity, and positional disorder of both biased and unbiased ligand environments. Anomalous X-ray diffraction studies were conducted on (FtbsL)Zn2Ni(py) (1), [K(C222)][(FtbsL)Zn2Ni] (2), and [K(THF)3][(FtbsL)Zn2Ni(NAd)] (3). Analysis of diffraction data collected at energies along the Ni and Zn K-edges on [Zn2Ni] clusters reveals data resolution, and the accuracy of the structural model greatly impacts the resonant scattering factors (f', f″) and their uncertainties. Occupancy studies on all three clusters were conducted in three ways and compared: (i) using the f' values of each metal site refined from diffraction data collected at energies along the Ni and Zn K-edges; (ii) using the f' value of each metal site refined from diffraction data collected with in-house, Cu Kα radiation; and (iii) refining each metal site as a Zn/Ni disordered pair and fixing the relative Zn-to-Ni occupancies as 2:1 across the core with supporting spectroscopic evidence from scanning electron microscope energy-dispersive spectroscopy. First, we observe highly ordered structural compositions, even when statistical mixing was anticipated; and second, we discovered that in-house X-ray diffraction collection was as precise in composition determination as synchrotron sources for this study.

Accompanying Bi Clusters as Charge Mediators Effectively Enhance Synergetic Redox of Bi2Sn2O7/ZnIn2S4 S-Scheme Heterostructure Composites.

Achieving synergistic oxidation and reduction represents a significant challenge in the field of photocatalysis. In this study, the hydrothermal/in situ construction of Bi atom clusters within Bi2Sn2O7/ZnIn2S4 (BSO/ZIS) heterostructures is reported. These clusters exhibit self-accelerating charge-transfer mechanisms facilitated by internal electric fields and bonding bridges, resulting in highly efficient light absorption and charge-transfer capabilities. In situ X-ray photoelectron spectroscopy (XPS) and Kelvin probe force microscopy (KPFM), as well as theoretical calculations, indicate that the canonical induction and promotion of electrons and holes by the Bi clusters lowers the activation energy of CHO* generation, allowing simultaneous CO2 reduction and toluene oxidation over the catalyst, and enhances proton-coupling and electron-transfer processes, resulting in a unique reaction mechanism. The CO2 and toluene as reactant, the Bi-Bi2Sn2O7/ZnIn2S4 (B-BSO/ZIS) heterostructure achieves a CO2 reduction rate to CO of 726.3µmol g-1h-1 (99.9% selectivity) and a toluene oxidation rate to benzaldehyde of 2362.0µmol g-1h-1 (98.0% selectivity), which increases in activity of 14.6 and 5.7 times compared to pristine ZnIn2S4. This study underscores the significance of modulating the photocatalytic pathway through the strategic selection of metal clusters and reactants, contributing to the rational design of photocatalysts for enhanced CO2 adsorption and stabilization of *H.

Lanthanide Molecular Clusters and Metal-Organic Layers Constructed by Manipulation of Substituents.

Usually, complexes with different connections and shapes are constructed by regulating the substituents. However, it is extremely challenging to construct two lanthanide complexes with different dimensions by only fine-tuning the substituents of the ligands, especially the substituents (-CH3 and -CH2CH3) with almost similar physical and chemical properties. Herein, by only regulating the substituents of the multidentate chelating ligands, two lanthanide complexes with different dimensions and connection modes were successfully constructed using a multicomponent "one-pot method" under the guidance of the multidentate chelating coordination method (MCC). They are the 11-nuclear lanthanide molecular cluster (Dy11) and the metal-organic layer (2D-Dy). Specifically, when the selected ligand is an imidazole-2-carboxaldehyde derivative and its substituent is -CH3, a layered 2D-Dy is obtained. The linker [Dy(HL1)3] with a propeller configuration is formed by chelating the Dy(III) ion with an acylhydrazone ligand (HL1) formed by the condensation of three salicylhydrazides and 1-methyl-1H-imidazole-2-carboxaldehyde. The above linkers were further linked alternately with propeller-shaped [Dy(NO3)3] as a secondary building unit (SBU) to form 2D-Dy. In addition, by changing the -CH3 on the ligand to -CH2CH3, we obtained an example of Dy11 formed by epitaxial assembly of two Dy(III) ions with an hourglass-shaped Dy9 as the core, and its molecular formula is [Dy11(HL2)8(μ3-OH)8(μ4-O)2(CH3O)4(NO3)4](NO3)5 18CH3OH. The cluster Dy11 was bombarded using high-resolution electrospray ionization mass spectrometry (HRESI-MS) and the molecular ion peaks of various fragments formed were captured. Based on the above molecular ion peaks, the possible fragmentation mechanisms of Dy11 were inferred to be Dy11 → Dy4(HL2)4 → Dy3(HL2)2 → Dy2(HL2)2 → Dy(HL2)2 and Dy11 → Dy(HL2)2/Dy2(HL2)2/Dy3(HL2)2/Dy4(HL2)4. This work is one of the rare examples where fine-tuning of ligand substituents leads to the formation of complexes of different dimensions, which promotes the progress of crystal engineering of lanthanide complexes.

Exploring the Superalkali Regime: Ab Initio Analysis of FnMn+1+ Cationic Clusters (M = Li, Na, K; n = 1-7)

Abstract Superalkalis with low ionization energies (IEs) has properties mimicking those of alkali atoms, therefore serving as potentially useful elements for constructing innovative nanostructured materials. Ab initio techniques were successfully utilized for investigating entirely new classes of linear metallic superalkali cationic clusters, FnMn+1+ cations (M = Li, Na and K and n = 1-7) using second-order Møller- Plesset perturbation theory (MP2). We have demonstrated a connection between the core atoms and the structural characteristics of such clusters by analyzing the NBO charge, bond distances and vertical electron affinity (EAv). The linear FnLin+1+, FnNan+1+ and FnKn+1+ (n = 1-7) cations have exceptionally low vertical electron affinities under the range of 3.61- 2.35 eV, 3.26- 2.19 eV and 2.84- 1.80 eV, respectively, and consequently, they ought to be characterized as novel superalkali clusters.

Identification of prognostic biomarker of non-small cell lung cancer based on mitochondrial permeability transition-driven necrosis-related genes and determination of anti-tumor effect of ARL14

BackgroundMitochondrial permeability transition (MPT)-driven necrosis (MPTDN) is a non-apoptotic mode of cell death triggered by oxidative stress and cytosolic Ca2+ overload. Recent evidence suggests that activation of MPTND can effectively induce cancer cell death and may represent a novel therapeutic strategy for cancer. Yet, the role of MPTDN-related genes in non-small cell lung cancer (NSCLC) remains unrevealed. This study aimed to identify MPTDN-related biomarkers for predicting prognosis and guiding treatment in NSCLC.MethodsGene expression profiles and clinical information of NSCLC were collected from public databases, and MPTDN-related genes were obtained from published article. Differential expressed MPTDN-related genes in NSCLC and control were screened, and molecular clusters were obtained. Based on the differentially expressed genes (DGEs) between clusters, univariate Cox and LASSO regression analyses were performed to screen biomarkers, followed by nomogram construction. Correlations between these biomarkers and immune cell infiltration, immune checkpoints, and chemotherapeutic agents were observed. Expression levels of MPTDN-related biomarkers were detected using RT-qPCR in NSCLC tissues and cells. Moreover, the biological function of ARL14 in NSLCL was verified in vitro.ResultsThirty-five differential MPTDN-related genes were identified, and two molecular clusters were obtained. Three biomarkers with prognostic values were finally screened, including ARL14, ZDHHC11B, and HLF. Among them, ARL14 was significantly upregulated in tumor samples, while ZDHHC11B and HLF were downregulated. Nomogram containing three genes exhibited predictive accuracy in 1, 3, and 5-year survival rates. Three gene were strongly associated with most immune cells, immune checkpoints, and drugs sensitivity. RT-qPCR confirmed that expression levels of three genes in tissues or cells were consistent with the results of bioinformatics analysis. Finally, ARL14 knockdown inhibited the malignant phenotype of NSCLC cells.ConclusionWe first performed the comprehensive analysis of MPTDN in NSCLC and screened three NSCLC-related biomarkers as promising biomarkers. ARL14 might be a new potential target for therapy of NSCLC.

Electric-dipole-momentum sensitive Coulomb explosion in doubly ionized CO dimer and trimer: An environmental effect at molecular-scale.

Molecular clusters are aggregates of molecules weakly bound by the van der Waals force between molecules. Removing one electron from each constitutive molecule results in van der Waals bond cleavages through Coulomb explosion. This provides an ideal prototype to further study the environmental effects played by one fragmented ion on the other one at the molecular scale. Here, we report an experimental measurement of the two-body Coulomb explosion of (CO)22+ and (CO)32+, produced in a 40keV Ar2+ double-electron capture collision with a CO dimer and trimer. Accurate reaction pathways are identified with the advanced ion-ion coincidence and momentum-imaging techniques. The measured kinetic energy release deviates from the calculated results based on the reciprocal of internuclear distance (i.e., Coulomb interaction only) and which, therefore, requires the inclusion of rotational energy of CO+ initiated by molecular electric-dipole momentum. Molecular dynamics simulations reveal that the separation defining the rotational energy takes place within a few hundred fs after the onset of dissociation. This molecular-scale environmental effect significantly brings calculations and measurements of the kinetic energy release into agreement.

Discovery of Novel FtsZ Inhibitors With Antimicrobial Activity by Virtual Screening and In Vitro Biological Evaluation.

The filamentous temperature-sensitive protein Z (FtsZ) plays a vital role in bacterial division, making it an important antibacterial target. The inhibitor activity targeting the cleft between the H7 helix and the C-terminal substructural domain exhibited superior binding compared to the GTP binding site. This highlights the potential of the cleft as a promising target for further inhibitor discovery. In this study, we established a virtual screening (VS) pipeline using Discovery Studio software and employed FRED for molecular docking and Functional-Class Fingerprints_6 (FCFP_6) for molecular clustering, resulting in the identification of 38 potentially active compounds. These 38 compounds were then subjected to the following FtsZ inhibition assays, resulting in the four active compounds B6, B21, B26, and B31. Further experiments showed that compounds B6 and B26 exhibited antimicrobial activity with minimum inhibitory concentration (MIC) values of 8 and 32µg/mL. Finally, molecular dynamics (MD) was used to analyze the binding modes of the protein-ligand. In addition, we predicted the physicochemical properties and toxicity of B6 and B26. In summary, our study successfully identified novel FtsZ inhibitors with antimicrobial activity through VS and in vitro biological evaluation, demonstrating their potential for further investigation.

Deciphering the Role of Vinylene Carbonate in Shaping CO2 Cluster Growth and Stability via Wavelet-Enhanced Microwave Spectroscopy.

This study presents the first integration of wavelet denoising with resonator-enhanced microwave spectroscopy to explore the formation and characteristics of gas-phase heterogeneous vinylene carbonate-(CO2)1-5 clusters. Through this innovative approach, faint spectral lines were detected with efficiency, enhancing our understanding of complex interaction patterns that govern the growth and stability of these molecular clusters. It was found that CO2 aggregates preferentially around the vinylene carbonate molecule through C···O tetrel bonds at the carbonyl and ether groups, altering the typical self-aggregation topology of free CO2 clusters. This leads to more symmetrical growth around the vinylene carbonate monomer. Our findings provide insights into the solvation mechanisms of compounds in supercritical CO2 thereby advancing the understanding of subnanoscale CO2 aggregation patterns.

Precisely Controlled Integration of Multiple Metal Cations in Diverse Metal‐Organic Framework Topologies via Messenger Building Unit Approach

Achieving precisely controlled multimetal configurations in the structure of metal‐organic frameworks (MOFs) through one‐pot reactions remains a synthetic challenge. The use of heterometallic molecular clusters as messenger building units (mBUs) is recently reported as a feasible approach to address this issue in the formation of MOFs with sra topology. Herein, the successful expansion of this approach is reported to achieve MOFs with distinct topologies through the use of linkers with different connectivities, such as the tritopic 1,3,5‐tris(4‐carboxyphenyl)benzene (H3BTB) and the tetratopic tetrakis(4‐carboxyphenyl)porphyrin, (H6TCPP). The reaction of Ga7M mBU (M = Ni, Co) with H3BTB and H6TCPP yields porous MOFs Ga2M‐BTB and Ga7M‐TCPP, with sit and fry topology, respectively. The MOFs incorporate the initially selected metal combinations in their inorganic secondary building units, as demonstrated by the use of X‐ray diffraction, X‐ray spectroscopies, electron microscopy, and gas sorption techniques. It is also shown that alginate‐based bead shaped composites can be formed with Ga7M‐TCPP MOFs, and are efficient heterogeneous photocatalysts, as demonstrated with their use in the aza‐Henry reaction, showing improvements in activity and selectivity as compared with single‐metal analogues.

Small gas adsorption on metal clusters on trimer form of graphyne: First-principles density functional theory study

Small gas adsorption on metal clusters on trimer form of graphyne: First-principles density functional theory study

Theory-Directed Ligand-Shell Engineering of Ultrasmall Gold Clusters: Remarkable Effects of Ligand Arrangement on Optical Properties.

Ligand-shell engineering of ultrasmall metal clusters is a burgeoning research field aiming to develop cluster-specific properties. However, predicting these properties prior to synthesis is challenging due to their high sensitivity to geometric and/or electronic variations in ultrasmall metal cores, hindering further exploration. In this study, we present a theory-directed ligand-shell design and significant red-shift in absorption of a prolate-shaped [Au8(diphosphine)4Cl2]2+ cluster by synthesizing and characterizing enantiopure octagold clusters bearing chiral BINAP-type ligands [BINAP = 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]. Crystallographic analysis reveals the predesigned ligand arrangement and twisted gold-core framework. The enantiomeric clusters show significant changes in both absorption and photoluminescence compared with a previous Au8 analogue and exhibit chiroptical signals. Furthermore, theoretical calculations visually unveil the atomic level origins of their optical and chiroptical absorption characteristics. This work not only highlights the effectiveness of ligand-shell engineering in creating unique photophysical properties but also offers a viable, theory-guided strategy for designing and functionalizing ligated metal clusters.

Cyclic cooperativity contributions determine the hydrogen bond strengths in molecular clusters.

In a recent communication (A. Shivhare, B. Dehariya, S. R. Gadre and M. M. Deshmukh, Phys. Chem. Chem. Phys., 2024, 26, 21332), we proposed a method for calculating the energy of a hydrogen bond (HB), which is common to two or more cyclic networks of HBs in water (H2O)n clusters. For this purpose, the sum of the cooperativity contributions (CCs) of these cyclic structures, estimated using the molecular tailoring approach (MTA)-based method, was added to the energy of this HB in the respective water dimer isolated from the cluster. The HB energies calculated in this fashion (ESynergeticHB) were in excellent agreement with their actual cluster counterparts (EclusterHB). In this work, we test the generality of this methodology. For this purpose, we employed clusters of ammonia (NH3)n, hydrogen sulphide (H2S)n, mixed (H2S)m(H2O)n, (NH3)m(H2O)n, methanol-water (CH3OH)m(H2O)n, and hydrogen fluoride-water (HF)m(H2O)n exhibiting HBs of variable strength (1 to 19 kcal mol-1). The HB energies in all these molecular clusters calculated using the present method were found to be accurate. The absolute difference between the ESynergeticHB and EclusterHB values in these clusters is found to be less than 0.5 kcal mol-1. Importantly, the present method not only enables accurate HB energy estimation in molecular clusters, but also offers qualitative guidelines for this purpose. The latter are based on the nature of cyclic cooperativity, exhibiting either full cyclic cooperativity (FCC), partial cyclic cooperativity (PCC) or anti-cooperativity (AC).

Molecular network analysis for detecting HIV transmission clusters: insights and implications

ObjectiveIn order to improve knowledge of HIV transmission dynamics and guide preventive and control strategies, this work uses molecular cluster analysis to objectively detect clusters of HIV genetic sequence similarity.Methods89 HIV-positive couples provided blood samples, and plasma was separated for pol region gene sequence amplification. Furthermore, analyzed HIV-1 pol fragment sequences from Nanjing patients between 2015 and 2019. HYPHY and Cytoscape were used to generate and illustrate molecular networks.ResultsIn this investigation of 89 double-positive pairs, it was discovered that the pairwise gene distance approach properly detected 82.02% of positive couples at an ideal gene distance of 0.014 substitution/loci. With an accuracy of 86.25%, the optimal parameter for the phylogenetic tree and gene distance approach was 90 + 0.045 substitution/loci. A molecular network was built for the Nanjing samples (2015–2019) using the optimum threshold of the previous technique. This network had 487 sequences with one misconnected cluster. There were 565 sequences in the network created by the latter approach that were not incorrectly connected.ConclusionFor HIV research, molecular cluster analysis provides novel insights. It helps with preventive and control methods by objectively identifying clusters with comparable genetic sequences, which enhances our knowledge of HIV transmission. Further developments will increase its importance for HIV/AIDS research and worldwide prevention.

Investigation of the Impact of Thionine Functionalization on Magnetoelastic Sensor Performance.

This study investigates the functionalization of gold-coated magnetoelastic sensors with thionine molecules, focusing on resonance frequency shifts. The functionalization process was characterized by using Raman spectroscopy and analyzed via scanning electron microscopy and atomic force microscopy, revealing the progressive formation of molecular clusters over time. Our results demonstrate that longer functionalization time leads to saturation of surface coverage and cluster formation, impacting the sensor's resonance frequency shifts. Such modifications offer insights into the adsorption process of these molecules on the sensor's gold surface, as well as its performance.

Emission Tuning of Nonconventional Luminescent Materials via Cluster Engineering.

Nonconventional Luminescent Materials (NLMs) with distinctive optical properties are garnering significant attention. A key challenge in their practical application lies in precisely controlling their emission behavior, particularly achieving excitation wavelength-independent emission, which is paramount for accurate chemical sensing. In this study, NLMs (Y1, Y2, Y3, and Y4) are synthesized via a click reaction, and it is found that excitation wavelength-dependent emission correlates with molecular cluster formation. Rigid NLMs (Y1, Y2) exhibit excitation-independent emission in dilute solutions with nanoscale clusters but become excitation-dependent at higher concentrations due to larger cluster formation. Flexible NLMs (Y3 and Y4) always show excitation-dependent emission, indicating a tendency for larger cluster formation. While these NLMs exhibit high photoluminescence quantum yields (PLQYs) in dilute solutions (0.1 mgmL-1) up to 38.0%, they suffer from significant aggregation-caused quenching (ACQ) in the solid state (as low as 0.5%). These findings provide insights into NLM luminescence mechanisms and offer a new approach for tuning their optical properties. With excellent optical properties, facile synthesis, and biocompatibility, these NLMs hold promise for bioimaging and other applications.

Porous 3d‐4f Coordination Clusters for Selective Visible‐Light Photocatalytic CO2 Reduction to CO

We report herein two families of porous coordination clusters (PCCs) with 216 nuclearity (M120RE96 or PCC‐216MR) and 300 nuclearity (Co144Gd156 or PCC‐300CG). For the first family M could be either nickel or cobalt, and RE = Pr, Nd, Sm, Eu, and Gd; while the latter features the highest nuclearity of transition‐rare earth metal clusters. Characterized by their cube‐like, hollow structures, these clusters exhibit the ability to absorb N2 and CO2. Besides, these clusters can be dissolved in both aqueous and acetonitrile/methanol solutions, and capable of acting as homogeneous catalysts for converting CO2 to CO under visible light. The gadolinium analogues of these clusters all show turnover numbers over 10000 and turnover frequencies over 1 s−1. In particular, the nickel based bimetallic cluster (PCC‐216NG) demonstrates near ly 100% selectivity for the reduction product, which may open a new direction for the design and development of PCCs based catalysts.

Porous 3 d-4 f Coordination Clusters for Selective Visible-Light Photocatalytic CO2 Reduction to CO.

We report herein two families of porous coordination clusters (PCCs) with 216 nuclearity (M120RE96 or PCC-216MR) and 300 nuclearity (Co144Gd156 or PCC-300CG). For the first family M could be either nickel or cobalt, and RE = Pr, Nd, Sm, Eu, and Gd; while the latter features the highest nuclearity of transition-rare earth metal clusters. Characterized by their cube-like, hollow structures, these clusters exhibit the ability to absorb N2 and CO2. Besides, these clusters can be dissolved in both aqueous and acetonitrile/methanol solutions, and capable of acting as homogeneous catalysts for converting CO2 to CO under visible light. The gadolinium analogues of these clusters all show turnover numbers over 10000 and turnover frequencies over 1 s-1. In particular, the nickel based bimetallic cluster (PCC-216NG) demonstrates nearly 100 % selectivity for the reduction product, which may open a new direction for the design and development of PCCs based catalysts.

Ionothermal Synthesis of Am4B22O42Cl12: A Chiral Cubic Americium Borate Cluster.

Ionic liquids were used as low temperature solvents for the synthesis of new lanthanide and transuranic-element (TRU) borate cluster structures. Ionothermal synthesis with the ionic liquid [BMIm]Cl (1-butyl-3-methylimidazolium chloride) yielded the La, Nd, and Am containing phases La4B22O42Cl12, Nd4B22O42Cl12, and Am4B22O42Cl12. The structures of the La, Nd, and Am borate clusters were determined by single crystal X-ray diffraction (SCXRD) and found to be cubic, in the chiral space group I23. Solid state NMR and Raman spectra confirm the structure descriptions. This represents the first ionothermal synthesis of an americium containing cluster compound, and the study of such low-temperature methods benefit work on TRU materials.

A living library concept to capture the dynamics and reactivity of mixed-metal clusters for catalysis.

The exploration of ligated metal clusters' chemical space is challenging, partly owing to an insufficiently targeted access to reactive clusters. Now, dynamic mixtures of clusters, defined as living libraries, are obtained through organometallic precursor chemistry. The libraries are populated with interrelated clusters, including transient and highly reactive ones, as well as more accessible but less reactive species. Their evolutions upon perturbation with substrate molecules are monitored and chemical information is gained without separation of the clusters. Here we prepared a library of all-hydrocarbon ligated Cu/Zn clusters and developed a bias-free computational framework suited to analyse the full compositional space that yields a reliable structural model for each cluster. This methodology enables efficient searches for structure-reactivity relationships relevant for catalysis with mixed-metal clusters: when treating the library with CO2 or 3-hexyne and H2, we discovered [Cu11Zn6](Cp*)8(CO2)2(HCO2) bearing a formate species related to CO2 reduction and [Cu9Zn7](Cp*)6(Hex)3(H)3 bearing C6 species related to alkyne semi-hydrogenation.