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Objective Cardiorenal syndrome type 4 (CRS4) is a complication of chronic kidney disease. Panax notoginseng saponins (PNS) have been confirmed to be efficient in cardiovascular diseases. Our study aimed to explore the therapeutic role and mechanism of PNS in CRS4. Methods CRS4 model rats and hypoxia-induced cardiomyocytes were treated with PNS, with and without pyroptosis inhibitor VX765 and ANRIL overexpression plasmids. Cardiac function and cardiorenal function biomarkers levels were measured by echocardiography and ELISA, respectively. Cardiac fibrosis was detected by Masson staining. Cell viability was determined by cell counting kit-8 and flow cytometry. Expression of fibrosis-related genes (COL-I, COL-III, TGF-β, α-SMA) and ANRIL was examined using RT-qPCR. Pyroptosis-related protein levels of NLRP3, ASC, IL-1β, TGF-β1, GSDMD-N, and caspase-1 were measured by western blotting or immunofluorescence staining. Results PNS improved cardiac function, and inhibited cardiac fibrosis and pyroptosis in a dose-dependent manner in model rats and injured H9c2 cells (p p p p Conclusion PNS inhibits pyroptosis by downregulating lncRNA-ANRIL in CRS4.

Background The gut microbiota has been identified as a source of pathogenic mediators in chronic kidney disease (CKD). A gut microbiota-dependent metabolite, trimethylamine N-oxide (TMAO), has been reported to be closely related to CKD complications. This study aimed to investigate the changes in intestinal microbiota and circulating levels of TMAO in Chinese patients with CKD. Methods The study comprised 50 paticipants including 30 patients with CKD and a control group of 20 healthy controls. Plasma TMAO levels were detected by high-performance liquid chromatography-tandem mass spectrometry, and gut microbiota was analysed using High-throughput sequencing. Results Compared to the healthy control group, the CKD patients had relatively lower albumin and hemoglobin levels and showed obviously impaired renal function and abnormal urine test results. Additionally, CKD patients showed increased plasma TMAO levels, especially those with a low glomerular filtration rate (GFR). Among the biochemical indices of the CKD patients, impaired renal function was the main contributor of the increased TMAO levels. High-throughput sequencing revealed obvious gut dysbiosis in CKD patients with biased community constitutions. Based on the Pearson correlation analysis, many bacteria positively or negatively correlated with TMAO production at the phylum and genus levels. Conclusions Our study demonstrated that gut microbiota dysbiosis and decreased GFR were the main causes of plasma TMAO level. Elevation, and inhibition of intestinal metabolite TMAO production may be the key to preventing CKD progression.

As the heaviest group 12 element known now, copernicium (Cn) often presents the oxidation states of +I, +II, and rarely +IV as in its homologue mercury. In this work we systematically studied the stability of some oxides, fluorides, and oxyfluorides of Cn by two-component relativistic calculations, and found that the CnF6 molecule with an oxidation state of +VI has an extraordinary stability. CnF6 may decompose into CnF4 by conquering an energy barrier of about 30 kcal/mol without markedly releasing heat. Our results indicates that CnF6 may exist under some special conditions.

We introduce in this work a unique parameter for the quantitative assessment of the intrinsic strength of the π interaction between two monomers forming a complex. The new parameter is a local intermonomer stretching force constant, based on the local mode theory, originally developed by Konkoli and Cremer, and derived from the set of nine possible intermonomer normal vibrational modes. The new local force constant was applied to a diverse set of more than 70 molecular complexes, which was divided into four groups. Group 1 includes atoms, ions, and small molecules interacting with benzene and substituted benzenes. Group 2 includes transition metal hydrides and oxides interacting with benzene while Group 3 involves ferrocenes, chromocenes, and titanium sandwich compounds. Group 4 presents an extension to oxygen π–hole interactions in comparison with in-plane hydrogen bonding. We found that the strength of the π interactions in these diverse molecular complexes can vary from weak interactions with predominantly electrostatic character, found, e.g., for argon–benzene complexes, to strong interactions with a substantial covalent nature, found, e.g., for ferrocenes; all being seamlessly described and compared with the new intermonomer local mode force constant, which also outperforms other descriptors such as an averaged force constant or a force constant guided by the electron density bond paths. We hope that our findings will inspire the community to apply the new parameter also to other intermonomer π interactions, enriching in this way the broad field of organometallic chemistry with a new efficient assessment tool.

The Sn + H2O reaction is important in both hydrogen production through solar thermochemical redox cycles and investigations like the treatment of nuclear reactors or flame inhibition. Based on single molecule model, this work systematically explores its possible reacting channels in different spin multiplicities at CCSD(T)//DFT level of theory to reveal the underlined mechanism for its reported efficient hydrogen production. It is found that the singlet and triplet potential energy surfaces cross each other during the water attacking process, which makes the hydrogen production channel in the singlet state energetically favored. Quantitative calculations about the possibility of surface crossing and spin inversion with respect to minimum energy crossing point, spin-orbit coupling coefficient and intersystem crossing probability confirm that the optimal reacting pathway involves the two-state reaction scenario. This special reactive pattern makes hydrogen production not only possible but also efficient. Analysis of the equilibrium constant of reactive channels and their variation with temperature reveals the performance of two-state reaction channel agrees well with reported data range and nontrivial temperature dependence.

Excessive cadmium (Cd) in rice grains is a serious food safety problem. The development of Cd-safe varieties requires the identification of germplasms and genes with major effect on Cd accumulation but without negative effects on other important traits. Here, we reported that OsCAX2, a member of the rice Cation/H+exchanger (CAX) family, is an important Cd transporter.OsCAX2encodes a tonoplast-localized protein and is strongly upregulated by Cd, mainly expresses in root exodermis, parenchyma in cortex, endodermis and stele cells. Depletion ofOsCAX2resulted in enhanced Cd sensitivity and root-to-shoot translocation in rice, while overexpression ofOsCAX2significantly increased Cd tolerance and reduced Cd transport by promoting root Cd influx and vacuolar storage, which ultimately reduced Cd transport via xylem.OsCAX2also had significant effects on tissues/organs distribution of Cd but had no effects on grain yield and agronomic traits. Importantly, theOsCAX2overexpressing lines had more than 70% lower grain Cd accumulation, increased iron (Fe), zinc (Zn) and manganese (Mn) and reduced copper (Cu) accumulation. Therefore,OsCAX2is an ideal gene for developing Cd-safe rice varieties via transgenic approach.

Zinc (Zn) deficiency and cadmium (Cd) stress are severe threats to the growth and development of plants. Increasing Zn content and/or decreasing Cd content in grain are also important objectives of rice breeding. However, the molecular mechanisms of Zn deficiency tolerance (ZDT) and Cd stress tolerance (CDT) are largely unknown in rice. Here, we report that a NAM/CUC2-like transcription factor

For the first singlet excited states C

Multi-trait (MT) genomic prediction models enable breeders to save phenotyping resources and increase the prediction accuracy of unobserved target traits by exploiting available information from non-target or auxiliary traits. Our study evaluated different MT models using 250 rice accessions from Asian countries genotyped and phenotyped for grain content of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), and cadmium (Cd). The predictive performance of MT models compared to a traditional single trait (ST) model was assessed by 1) applying different cross-validation strategies (CV1, CV2, and CV3) inferring varied phenotyping patterns and budgets; 2) accounting for local epistatic effects along with the main additive effect in MT models; and 3) using a selective marker panel composed of trait-associated SNPs in MT models. MT models were not statistically significantly (p < 0.05) superior to ST model under CV1, where no phenotypic information was available for the accessions in the test set. After including phenotypes from auxiliary traits in both training and test sets (MT-CV2) or simply in the test set (MT-CV3), MT models significantly (p < 0.05) outperformed ST model for all the traits. The highest increases in the predictive ability of MT models relative to ST models were 11.1% (Mn), 11.5 (Cd), 33.3% (Fe), 95.2% (Cu) and 126% (Zn). Accounting for the local epistatic effects using a haplotype-based model further improved the predictive ability of MT models by 4.6% (Cu), 3.8% (Zn), and 3.5% (Cd) relative to MT models with only additive effects. The predictive ability of the haplotype-based model was not improved after optimizing the marker panel by only considering the markers associated with the traits. This study first assessed the local epistatic effects and marker optimization strategies in the MT genomic prediction framework and then illustrated the power of the MT model in predicting trace element traits in rice for the effective use of genetic resources to improve the nutritional quality of rice grain.

Hydride ligands of transition metal polyhydride complexes with a high coordination number are prone to fluxionality leading to interesting structural dynamics. However, the underlying polytopal rearrangement pathways have been rarely studied. Based on quantum chemical calculations carried out in this work with density functional theory and coupled-cluster theory, two new fluxional mechanisms have been identified for the rhenium polyhydride complex ReH5(PPh3)2(pyridine) to jointly account for two consecutive coalescence events in the variable-temperature NMR spectra upon heating: lateral and basal three-arm turnstile rotation. The frequently cited pseudorotation in ReH5(PPh3)2(pyridine) (Lee et al. Inorg. Chem. 1996, 35, 695) turns out to be a three-step process including two lateral three-arm turnstile steps and one basal turnstile step in between. The new fluxional mechanisms discovered in this work may also exist in other transition metal polyhydrides.

Pd/CeO2 catalysts show superior catalytic performance owing to their optimal cycling activity and stability. In this study, single-atom Pd and eight-atom Pd nanoparticle clusters were supported on the surface of CeO2(110) to investigate the effect of loaded-metal size on the catalytic performance of the Pd–CeO2 system for CO2 reduction. We investigated the CO2 reduction reaction (CRR) that produces C1 products (CO, HCOOH, CH3OH, and CH4) on Pd8/CeO2 and Pd/CeO2 by density functional theory. The structures, CO2 adsorption configurations, and CO2 reduction mechanisms of these two electrocatalysts were systematically studied. Subsequently, different reduction pathways on Pd8/CeO2 and Pd/CeO2 were investigated to identify the optimal reaction pathway for further assessment. The results showed that both of these catalysts are more selective towards the production of CH3OH than CH4. Moreover, compared to Pd/CeO2 and Pd4/CeO2 (from a previously reported study) the production of CH3OH via the CRR on Pd8/CeO2 exhibited the lowest limiting potential. These results demonstrate the superiority of Pd8/CeO2 as an electrocatalyst for the electrochemical reduction of CO2 to CH3OH.

Despite the chemistry of actinide-ligand bonding is continuing and of burgeoning interest, investigations of the chemical bonding of bimetallic complexes involving transuranics remain relatively less, and there are rarely studies on the bonding features between actinide and coinage metals (CM). We present a systematic research on the series of An@Au7 (An = Th to Cm), UCM7 (CM = Cu, Ag, Au), and WAu7 clusters to investigate the unique geometries, electronic structures, and chemical bonding between An 5f6d orbitals and CM ns orbitals, and to find their periodicity across the actinides and within the group of transition metals. A unique planar wheel-like structure for An@Au7 clusters with the help of actinide metals encapsulation via spin-orbit coupling, resulting in An(III). Instead, the transition-metal (TM) element W retains its usual six-gold-coordination structure in WAu7, thus forcing the seventh Au out of plane. The An-CM interactions, depending on the ion radii, become stronger with the increase of the atomic number of the actinide metals, as well as the CM. These results show that the presence of actinides in clusters can lead to unique electronic and geometrical structures.

The analysis of chemical bonding in crystal structures and surfaces is an important research topic in theoretical chemistry. In this work, we present a PyMOL plugin, named LModeA-nano, as implementation of the local vibrational mode theory for periodic systems (Tao et al.

The nonahydridorhenate dianion ReH

As the heaviest group 12 element known currently, copernicium (Cn) often presents the oxidation states of I+, II+, and rarely IV+ as in its homologue mercury. In this work we systematically studied the stability of some oxides, fluorides, and oxyfluorides of Cn by two-component relativistic calculations and found that the CnF

Pd/CeO

The coordination number of a given element affects its behavior, and consequently, there is great interest in understanding the related chemistry, which could greatly promote the extension and development of new materials, but remains challenging. Herein, we report a new record high coordination number (CN) for actinides established in the cage-like An(BH)24 (An = Th to Cm) via using relativistic quantum chemistry methods. Analysis of U(BH)n (n = 1 to 24) confirmed these series of systems as being geometric minima, with the BH acting as a ligand located in the first shell around the uranium. In contrast, global searches revealed a low CN half-cage structure for UB24, which could be extended to the series of AnB24 materials and which prevails over the competing structural isomers, such as cages. The intrinsic geometric difference for AnB24 and An(BH)24 mainly arise from the B sp3 hybridization in borane inducing strong interactions between An 5f6d7s hybrid orbitals and B 2pz orbitals in An(BH)24 compared to that of AnB24. This fundamental trend presents a valuable insight for future experimental endeavors searching for isolable complexes with high-coordination actinide and provides details of a new structural motif of boron clusters and nanostructures.

The analytic derivative algorithm for the effective contact densities obtained by the exact two-component (X2C) relativistic Hamiltonian is extended to the local approximations to X2C to achieve a higher computational efficiency without losing accuracy. The new algorithm has been implemented in a standalone program, which can utilize the molecular orbitals from state-of-the-art ab initio or density functional theory (DFT) calculations by other quantum chemistry programs in connection with various relativistic Hamiltonians. With the help of the utility program, the effective contact densities as well as the related Mössbauer isomer shifts can be studied by various advanced single-reference and multi-reference ab initio methods as long as the canonical or natural orbitals are available. Using the developed algorithm, the effective contact densities and the Mössbauer isomer shifts in a series of iron compounds and in HgFn (n = 1, 2, 4, and 6) molecules were studied. The obtained results show that (1) adequate account of the static electron correlation significantly improves the agreement of the theoretical 57Fe effective contact densities with the experimental isomer shifts, and (2) the non-monotonous changes of the effective contact density in a series of HgFn compounds are caused by the increasing screening effect due to shrinking of the Hg 5d orbitals.

Lanthanide oxo compounds are of vital importance in lanthanide chemistry, as well as in environmental and materials sciences. Praseodymium, as an exceptional element in lanthanides which can form a +V formal oxidation state (OSf) besides the dominant +III among the 4f-block element, displays the significant participation of the Pr 4f orbitals in bonding interactions which is commonly crucial in stabilizing the high oxidation state of Pr in PrO2+ and NPrO species. Here, we report a systematic theoretical study on the structures and stabilities of a series of XPrO (X: B, Al, C, Si, N, P, As, O, S, F, Cl) compounds along with [XPrO]+ cation (X: O, S) and [X3PrO] complexes (X: F and Cl). This work reveals that Pr is able to achieve the lowest and highest OSf and the OSf exhibits periodic variation from +I in BOPr and AlOPr to +II in SiOPr to +III in CPrO, FPrO, ClPrO and AsPrO to +IV in OPrO and SPrO and even to +V in NPrO, [OPrO]+, [SPrO]+, F3PrO and Cl3PrO. We found that the molecular structures are correlated to the Pr oxidation state due to the highly important 4f orbital in the chemical bonding of the high oxidation state compounds. Thus, not only the electronegativity of the ligand but also the quasi-degenerate Pr valence 4f orbitals, namely energetic covalency, control the oxidation state and play a fundamental role in affecting the electronic structural stability of Pr(v) compounds as well. This work demonstrates the structurally directing role of the f-orbital in the formation of the linear structure and is constructive for achieving the higher oxidation state of a given element by tuning the ligand.

As a group 12 element, mercury locating at the sixth row with a valent electronic configuration of 5 d 10 6 s 2 has been treated as a main group element featuring +I and +II oxidation states for a long time. C. K. Jorgensen conjectured the existences of HgF4 and HgF6 molecules in early 1960s, where HgF4 was first synthesized in 2007, but HgF6 as the Hg(+VI) compound was less known. In this paper we explored the electronic structure and decomposition paths of HgF6 by scalar (X1C) and 2-component relativistic (X2C) density functional calculations and more accurate multi-reference NEVPT2 calculations. It is found that the HgF6 molecule, where the mercury atom presents an extraordinary high oxidation state of +VI, is protected by a considerable barrier height of about 22 kcal/mol for the decomposition into HgF4 and two isolated fluorine atoms. The results propose that HgF6 is kinetically stable and may exist under exorbitant conditions.

AIM Incremental haemodialysis (HD) regimen has recently gained attention. However, its efficacy and safety, compared with conventional thrice-weekly HD, are controversial and previous research results are not convincing. We sought to conduct a meta-analysis to evaluate the benefits and limitations of incremental HD regimen in patients with end-stage renal disease. METHODS We searched PubMed, Embase, and the Cochrane Central Register databases for controlled trials published until January 2017. Outcomes of interest included baseline patient characteristics, mortality risk, renal function, urine volume, laboratory values, and hospitalization rate. RESULTS Overall, 16 studies (n = 252 330), including 15 observational studies and 1 cross-sectional study, were included. Incremental HD reduced mortality risk, compared with conventional HD (risk ratio [RR], 0.797; 95% confidence interval [CI], 0.731-0.870; P < 0.001; I2 = 0%). Renal function (standardized mean difference [SMD] = 0.677, 95% CI: 0.035 to 1.318, P = 0.039; I2 = 92.7%) and urine volume (weighted mean difference [WMD] = 333.37, 95% CI: 86.81 to 579.93, P = 0.008; I2 = 92.7%) were also better preserved in patients on incremental HD. Other clinical outcomes, including serum levels of calcium, phosphate, albumin, haemoglobin, and hospitalization rate, were similar between groups. CONCLUSION An incremental therapeutic approach as a beginning haemodialysis regimen is associated with lower mortality and better preservation of greater residual renal function.

Hydride ligands of transition metal polyhydride complexes with a high coordination number are prone to fluxionality leading to interesting structural dynamics. However, the underlying polytopal rearrangement pathways have been rarely studied. Based on quantum chemical calculations carried out in this work with density functional theory and coupled-cluster theory, two new fluxional mechanisms have been identified for the rhenium polyhydride complex ReH

Zn chlorin (Znchl) is easy to synthesize and has similar optical properties to those of bacteriochlorophyll c in the nature, which is expected to be used as a light-harvesting antenna system in artificial photosynthesis. In order to further explore the optical characteristics of Znchl, various sizes of a parallel layered Znchl-aggregate model and the THF-Znchl explicit solvent monomer model were constructed in this study, and their Qy excited state properties were simulated by using time-dependent density functional theory (TDDFT) and exciton theory. For the Znchl monomer, with a combination of the explicit solvent model and the implicit solvation model based on density (SMD), the calculated Qy excitation energy agreed very well with the experimental one. The Znchl aggregates may be simplified to a Zn36 model to reproduce the experimental Qy absorption spectrum by the Förster coupling theory. The proposed Znchl aggregate model provides a good foundation for the future exploration of other properties of Znchl and simulations of artificial light-harvesting antennas. The results also indicate that J-aggregrates along z-direction, due to intermolecular coordination bonds, are the dominant factor in extending the Qy band of Znchl into the near infrared region.

Despite the chemistry of actinide-ligand bonding is continuing and of burgeoning interest, investigations of the chemical bonding of bimetallic complexes involving transuranics remain relatively less, and there are rarely studies on the bonding features between actinide and coinage metals (CM). We present a systematic research on the series of An@Au

Visualizing vibrational motions calculated with different ab initio packages requires dedicated post-processing tools. Here, we present a PyMOL plugin called PyVibMS for visualizing the vibrational motions for both molecular and solid systems calculated by mainstream quantum chemical computer programs including Gaussian, Q-Chem, VASP, and CRYSTAL. Benefiting from the continuing development of the PyMOL platform, PyVibMS provides powerful functionalities and user-friendly interface. PyVibMS was written in Python and its open-source nature makes it flexible and sustainable. As an example, the motions of the Konkoli-Cremer local vibrational modes are shown in this work for the first time. PyVibMS is freely available at https://github.com/smutao/PyVibMS . Graphical abstract In this work, a PyMOL plugin named PyVibMS is developed to visualize molecular and lattice vibrations.

The local vibrational mode analysis developed by Konkoli and Cremer has been successfully applied to characterize the intrinsic bond strength via local bond stretching force constants in molecular systems. A wealth of new insights into covalent bonding and weak chemical interactions ranging from hydrogen, halogen, pnicogen, and chalcogen to tetrel bonding has been obtained. In this work we extend the local vibrational mode analysis to periodic systems, i.e. crystals, allowing for the first time a quantitative in situ measure of bond strength in the extended systems of one, two, and three dimensions. We present the study of one-dimensional polyacetylene and hydrogen fluoride chains and two-dimensional layers of graphene, water, and melamine-cyanurate as well as three-dimensional ice I

This research builds upon Hunt and Vitell's ethical decision-making model to examine consumers' engagement in green behaviors. Using survey data collected from Hong Kong and the United States and with structural equation modelling and bootstrap analyses, it shows that consumers' prevention focus and promotion focus positively affect their ethical idealism (βHK,US = 0.29, 0.19) and relativism (βHK,US = 0.15, 0.21), respectively. Furthermore, idealism positively influences consumers' corresponding ethical judgments (βHK,US = 0.18, 0.31) and decisions, and this influence is higher when the focal green behavior is high in moral intensity (βHK,US = 0.13, 0.12). Contrarily, ethical relativism has a negative impact on the same judgments (βHK,US = −0.11, −0.10) and decisions, and this impact is stronger when consumers' attention to social comparison information is low (βHK,US = 0.10, 0.11). This research contributes to the literature on green behaviors, regulatory focus and consumer ethics, and offers practical insights into promoting green behaviors among consumers.

The conformational properties of ring compounds such as cycloalkanes determine to a large extent their stability and reactivity. Therefore, the investigation of conformational processes such as ring inversion and/or ring pseudorotation has attracted a lot of attention over the past decades. An in-depth conformational analysis of ring compounds requires mapping the relevant parts of the conformational energy surface at stationary and also at non-stationary points. However, the latter is not feasible by a description of the ring with Cartesian or internal coordinates. We provide in this work, a solution to this problem by introducing a new coordinate system based on the Cremer–Pople puckering and deformation coordinates. Furthermore, analytic first- and second-order derivatives of puckering and deformation coordinates, i.e., B-matrices and D-tensors, were developed simplifying geometry optimization and frequency calculations. The new coordinate system is applied to map the potential energy surfaces and reaction paths of cycloheptane (C7H14), cyclooctane (C8H16), and cyclo[18]carbon (C18) at the quantum chemical level and to determine for the first time all stationary points of these ring compounds in a systematic way.

In this work a new curvilinear coordinate system is presented for the comprehensive description of polytopal rearrangements of N-coordinate compounds (N = 4-7) and systems containing an N-coordinate subunit. It is based on normal vibrational modes and a natural extension of the Cremer-Pople puckering coordinates ( J. Am. Chem. Soc. 1975, 97, 1354) together with the Zou-Izotov-Cremer deformation coordinates ( J. Phys. Chem. A 2011, 115, 8731) for ring structures to N-coordinate systems. We demonstrate that the new curvilinear coordinates are ideal reaction coordinates describing fluxional rearrangement pathways by revisiting the Berry pseudorotation and the lever mechanism in sulfur tetrafluoride, the Berry pseudorotation and two Muetterties' mechanisms in pentavalent compounds, the chimeric pseudorotation in iodine pentafluoride, Bailar and Ray-Dutt twists in hexacoordinate tris-chelates as well as the Bartell mechanism in iodine heptafluoride. The results of our study reveal that this dedicated curvilinear coordinate system can be applied to most coordination compounds opening new ways for the systematic modeling of fluxional processes.

The coordination number of a given element behaving to understand its chemistry shows a great interest, which greatly promotes the extension and development of new materials, but remains challenging. Herein we report a new record high coordination number (CN) for actinide established in the cage-like An(BH)24 (An = Th to Cm) via using relativistic quantum chemistry methods. Analysis of U(BH)n (n = 1 to 24) confirms these series of systems being as geometric minima, with the BH as a ligand located in the first shell around the uranium. Contrast, global searches reveal the low CN half-cage structure for UB24, which is extended to the series of AnB24 and prevails over the competing structural isomers such as cage. The intrinsic geometric difference for AnB24 and An(BH)24 mainly arise from the B sp3 hybridization in borane inducing strong interactions between An 5f6d7s hybrid orbitals and B 2pz orbitals in An(BH)24 comparing to that of AnB24. The fundamental trend presents a valuable insight for future experimental endeavor searching for isolable complexes with high-coordination actinide and provides a new structural motif of boron clusters and nanostructures.

Herein we report a new record coordination number of 24 for actinide established in the cage-like An(BH)24 (An = Th to Cm) via using relativistic quantum chemistry methods. Analysis of U(BH)n (n = 1 to 24) confirms these series of systems being as geometric minima, with the BH as a ligand located in the first shell around the uranium. However, our additional global searches reveal the lowest-energy half-cage structure for UB24, which is extended to the series of AnB24 and prevails over the competing structural isomers such as cage. The intrinsic geometric difference for AnB24 and An(BH)24 mainly arise from the B sp3 hybridization in borane inducing strong interactions between An 5f6d7s hybrid orbitals and B 2pz orbitals in An(BH)24 comparing to that of AnB24. The fundamental trend presents a valuable insight for future experimental endeavor searching for isolable complexes with high-coordination actinide and provides a new structural motif of boron clusters and nanostructures.

Utilizing the analytic derivative formalism for the Mossbauer isomer shift in connection with the Dirac-exact two-component Normalized Elimination of the Small Component (2c-NESC) method a new appr...

Boranes and carboranes form non-classical H-bonds with the π-face of an arene provided entropic factors are excluded, for example via a suitably designed template. The self-assembled Ir-dithiolene phosphine complexes of the type [Cp∗Ir(PR3)S2C2B10H10] (R = C6H4X, X = H, F, OMe) provide such a template. Steric crowding causes that one of the B-H bonds of the carborane is positioned above the phenyl plane of R to form a non-classical B-H…π hydrogen bond. For the gas phase, this is predicted by quantum chemical calculations of the local B-H…π stretching force constants. The solid-state structures of six [Cp∗Ir(PR3)S2C2B10H10] complexes synthesized are in close agreement with the quantum chemical predictions thus suggesting the existence of B-H…π hydrogen bonds. The 1H[11B] NMR titration experiments reveal that non-covalent B-H…π bonds also exists in solution. Calculations show that the bond strength order of the B-H…π H-bond determined with the help of the local stretching force constant is 0.35, comparable to what is found for the H-bond in the water dimer. However, the B-H…π H-bond is electrostatic in nature as confirmed by the topological analysis of the electron density ρ(r). The role of this H-bond in carborane supramolecular chemistry is elucidated and discussed.

The electronic states of OsSi are calculated by multi-state N-electron valence state second order perturbation theory (MS-NEVPT2) with all-electron basis sets. The relativistic effects are considered comprehensively that allows us to identify the X3Σ0+– ground state. The theoretical equilibrium bond length 2.103 A is close to the experimental measurement of 2.1207 A while the vibrational frequency 466 cm–1 is smaller than the experimental value of 516 cm–1. Two excited states, namely 3Π1(I) and 3Π1(II), are located at 15568 and 18316 cm–1 above the ground state, respectively. The 3Π1(I) ← X3Σ0+– transition has been assigned to the experimental spectra at 15729 cm–1 and 3Π1(II) ← X3Σ0+– may produce the bands near 18469 cm–1. Although the latter transition energy is in accord with the experimental spectra, theoretical calculations give too small oscillator strength. Moreover, plenty of excited states with considerable oscillator strengths are located that could serve as reference data in future experiments....

By use of the theoretical method of density functional theory (DFT), we systemically investigate the chalcogen doped Cu4 metal clusters (Cu4O, Cu4S, and Cu4Se) as catalysts for the electrochemical CO2 reduction with toluene as solvent. These doped clusters have efficient catalytic properties which can reduce CO2 to CH4 and a small amount of CH3OH. In the case of CO2 hydrogenation to CH4, the reaction barrier of the Cu4O cluster and Cu4S cluster are reduced by 0.37 eV and 0.15 eV, respectively, compared with the pristine Cu4 cluster. The calculation results also show the overpotentials for the CO2 hydrogenation to CH4 in the order of Cu4S

Using catastrophe theory and the concept of a mutation path, an algorithm is developed that leads to the direct correlation of the normal vibrational modes of two structurally related molecules. The mutation path is defined by weighted incremental changes in mass and geometry of the molecules in question, which are successively applied to mutate a molecule into a structurally related molecule and thus continuously converting their normal vibrational spectra from one into the other. Correlation diagrams are generated that accurately relate the normal vibrational modes to each other by utilizing mode-mode overlap criteria and resolving allowed and avoided crossings of vibrational eigenstates. The limitations of normal mode correlation, however, foster the correlation of local vibrational modes, which offer a novel vibrational measure of similarity. It will be shown how this will open new avenues for chemical studies. © 2017 Wiley Periodicals, Inc.