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Seven three dimensional (3D) uranyl organic frameworks (UOFs), formulated as [NH4 ][(UO2 )3 (HTTDS)(H2 O)] (1), [(UO2 )4 (HTTDS)2 ](HIM)6 (2, IM=imidazole), [(UO2 )4 (TTDS)(H2 O)2 (Phen)2 ] (3, Phen=1,10-phenanthroline), [Zn(H2 O)4 ]0.5 [(UO2 )3 (HTTDS)(H2 O)4 ] (4), and {(UO2 )2 [Zn(H2 O)3 ]2 (TTDS)} (5), {Zn(UO2 )2 (H2 O)(Dib)0.5 (HDib)(HTTDS)} (6, Dib=1,4-di(1H-imidazol-1-yl)benzene) and [Na]{(UO2 )4 [Cu3 (u3 -OH)(H2 O)7 ](TTDS)2 } (7) have been hydrothermally prepared using a rigid octadentate carboxylate ligand, tetrakis(3,5-dicarboxyphenyl)silicon(H8 TTDS). These UOFs have different 3D self-assembled structures as a function of co-ligands, structure-directing agents and transition metals. The structure of 1 has an infinite ribbon formed by the UO7 pentagonal bipyramid bridged by carboxylate groups. With further introduction of auxiliary N-donor ligands, different structure of 2 and 3 are formed, in 2 the imidazole serves as space filler, while in 3 the Phen are bound to [UO2 ]2+ units as co-ligands. The second metal centers were introduced in the syntheses of 4-7, and in all cases, they are part of the final structures, either as a counterion (4) or as a component of framework (5-7). Interesting, in 7, a rare polyoxometalate [Cu3 (μ3 -OH)O7 (O2 CR)4 ] cluster was found in the structure. It acts as an inorganic building unit together with the dimer [(UO2 )2 (O2 CR)4 ] unit. Those uranyl carboxylates were sufficiently determined by single crystal X-ray diffraction, and their topological structures and luminescence properties were analyzed in detail.

The study of non-conjugated luminescent polymers (NCLPs) with fluorescence and long-lived room-temperature phosphorescence is of great significance for revealing the essence of NCLPs luminescence, which has gradually attracted the attention of researchers in recent years. Herein, polymethylol (PMO) and poly(3-butene-1,2-diol) (PBD) with polyhydroxyl structures were prepared and their luminescence behaviors were investigated to further reveal the clusteroluminescence (CL) mechanism. Compared with the weak or even non-luminescent behavior of polyvinyl alcohol, PMO and PBD exhibit cyan-blue fluorescence with quantum yields of ca. 12% and green room-temperature phosphorescence with lifetimes of ca. 89 ms in the solid state. Both fluorescence and phosphorescence exhibit typical excitation-dependent CL behavior. Experimental and theoretical analyses show that the strong hydrogen-bonding interaction of PMO and PBD greatly promotes the formation of oxygen clusters and the through-space n-n interaction of oxygen atoms, enabling fluorescence and phosphorescence emission. The results of this work have important implications for understanding the clusteroluminescence mechanism of NCLPs and provide a new polymer design strategy for the rational design of novel NCLPs materials.

Objective To observe the diastolic wall shear stress (WSS) pattern of the left ventricle (LV) by using vector flow mapping (VFM) in normal subjects. Methods A total of 371 healthy volunteers were recruited into this study and divided into four age groups. The LV WSS was measured at each diastolic phase, and the mapping of WSS was analyzed. Results Among groups I, II and III, The absolute value of WSS of Anterolateral，Inferoseptal and Anterospetal segments in phase D1；WSS values of inferolateral，Inferoseptal and Anterospetal segments in phase D4 all showed an increasing trend with age. In terms of gender differences, In most cases，women had greater diastolic WSS values compared to men. For each age group, the log-transformed WSS value appeared the increasing-decreasing-increasing trend from phase D1 to D4, with a peak value at the rapid filling phase.Multivariate backward stepwise linear regression analysis revealed that the certain segments log-transformed WSS was independently related to conventional parameters in evaluating diastolic function（mitral lateral E/e', septal E/e', mitral lateral e', septal e' and LAVI）.Conclusions In diastolic period, segmental LV WSS shows a regular variation phenomenon and has specific age- and gender-related patterns in different diastolic phases. The mapping of WSS may help identify the diastolic hemodynamic changes or diastolic function phase by phase.

The newly discovered cage-like borospherene D2d B40 with two η6-B6 hexagons and four η7-B7 heptagons on the surface may serve as an effective multi-dentate ligand to coordinate transition metals. Based upon extensive density functional theory calculations, we present herein the possibility of the exohedral complex series (C6H6Cr)n&B40 (n = 1–6) with n Cr centres sandwiched between the central η6/7-B40 unit and n planar η6-C6H6 ligands. C6H6Cr fragments in (C6H6Cr)n&B40 occupy the η6-B6 hexagonal coordination site atop the B40 cage first, the four neighboring η7-B7 heptagons on the waist next, and finally the η6-B6 hexagon at the bottom, forming a multinuclear complex series effectively stabilized by n C6H6Cr fragments. The two η6-B6 hexagons and four η7-B7 heptagons on the spherical surface of B40 can be practically viewed as six independent coordination sites to coordinate Cr centers with almost the same coordination energies. Detailed bonding analyses indicate that the eclipsed C2v C6H6Cr&B40 (1-1) possesses a coordination bonding pattern similar to that of dibenzenechromium, with the B40 ligand inheriting the σ + π double delocalization bonding pattern of the parent borospherene. The IR, Raman, and UV–vis absorption spectra of C2v C6H6Cr&B40 (1-1) are theoretically simulated to facilitate its future experimental characterization.

Boron and metal-doped boron nanoclusters possess unique fluxional behaviors in dynamics. Detailed bonding analyses performed in this work indicate that, similar to the experimentally observed B2-[Ta@B18]− (1), the theoretically predicted tubular molecular rotors B3-[Ta@B18] (2) and B4-[Ta@B18]+ (3) possess typical fluxional 4c–2e and 3c–2e σ-bonds atop the Ta-centered [Ta@B18] double-ring tube between the Bn unit (n = 3, 4) and upper B9 ring, unveiling the fluxional bonding nature of the Bn-[Ta@B18]q complex series (n = 2–4, q = n − 3) which follow the 18-electron rule in different charge states. Chiral conversions via pseudo-rotations are observed in the fluxional processes between the Bn unit (n = 3, 4) and Ta-centered [Ta@B18] double-ring tube.

Inspired by recent discoveries of alkaline-earth octacarbonyls and based on extensive first-principles theory investigations, we predict herein the possibility of perfect cube-like alkali octacarbonyls M(CO) 8 − (Oh, 3A1g) (1) (M = K, Rb) which satisfy the 18-electron rule in an octacoordinate cubic field with (n − 1)d-orbital participation of alkali metal center playing an important role in M–CO coordination interaction. The slightly elongated neutral M(CO)8 (D4h, 2B1g) (3) turn out to be similar with the experimentally observed Ba(CO) 8 + monocation in an octacoordinate tetragonal field. Detailed orbital analyses indicate that, similar to neutral alkaline-earth octacarbonyls, M(CO) 8 − monoanions possess the superatomic electronic configuration of S2P6D8F2, with the alkali–CO coordination interaction mainly originating from M(dπ) → (CO)8(π*) backdonations which result in strong red shifts of the C–O stretching frequencies relative to free CO.

Detailed molecular orbital and bonding analyses reveal the existence of both fluxional σ- and π-bonds in the global minima CsB182- (1) and Cs MB18 (3) and transition states CsB182- (2) and CsMB18- (4) of B182- dianion and MB18- monoanions (M = K, Rb, and Cs). It is the fluxional bonds that facilitate the fluxional behaviors of the quasi-planar B182- and half-sandwich MB18- which possess energy barriers smaller than the difference of the corresponding zero-point corrections. © 2019 Wiley Periodicals, Inc.

As the first all-boron fullerene observed in experiments, cage-like borospherene B40 has attracted considerable attention in recent years. However, B40 has been proved to be chemically reactive and tends to coalesce with one another via the formation of covalent bonds. We explore herein the possibility of low-dimensional functional networks of B40 with effective transition-metal intercalations. We find that the four equivalent B7 heptagons on the waist of each B40 can serve as effective ligands to coordinate various transition metal centers in exohedral motifs. The intercalated metal atoms entail these networks with a variety of intriguing properties. The two-dimensional (2D) Cr2B40 network is a ferromagnetic metal while the 2D Zn2B40 network becomes semiconducting. In contrast, other 2D M2B40 (M = Sc, Ti, V, Mn, Fe, Co, Ni and Cu) networks and 1D CrB40 belong to nonmagnetic metals. The 3D Cr3B40 network is a magnetic metal. This work presents the viable possibility of assembling Mn&B40 metalloborospherenes into stable functional nanomaterials via effective transition-metal intercalations with potential applications in electronic and spintronic devices.

Chirality plays an important role in nature. Nanoclusters can also exhibit chiral properties. We report herein a joint experimental and theoretical investigation on the geometric and electronic structures of B31− and B32− clusters, using photoelectron spectroscopy in combination with first-principles calculations. Two degenerate quasi-planar chiral C1 enantiomers (I and II, 1A) with a central hexagonal vacancy are identified as the global minima of B31−. For B32−, two degenerate boat-like quasi-planar chiral C2 structures (VI and VII, 2A) with a central hexagonal vacancy are also found as the global minima, with a low-lying chair-like Ci B32− (VIII, 2Au) also present in the experiment as a minor isomer. The chiral conversions in quasi-planar B31− and B32− clusters are investigated and relatively low barriers are found due to the high flexibility of these monolayer clusters, which feature multiple delocalized σ and π bonds over buckled molecular surfaces.

Crystalline borophene quantum dots with two-photo fluorescence and their derivative boron nanospheres with hydrazine hydrate-dependent photoluminescence properties were prepared by an efficient high-power sonication method combined with chemical exfoliation and a one-step chemical coupling strategy, respectively. This work would extend the practical lighting applications of B-rich nanomaterials.

Pulmonary arterial hypertension (PAH) is a devastating pulmonary circulation disease lacking high-efficiency therapeutics. The present study aims to decipher the therapeutic mechanism of Rhodiola crenulata, a well-known traditional chinese medicine with cardiopulmonary protection capacity, on PAH by exploiting functional lipidomics. The rat model with PAH was successfully established for first, following Rhodiola crenulata water extract (RCE) treatment, then analysis of chemical constituents of RCE was performed, additional morphologic, hemodynamic, echocardiographic measurements were examined, further targeted lipidomics assay was performed to identify differential lipidomes, at last accordingly mechanism assay was done by combining qRT-PCR, Western blot and ELISA. Differential lipidomes were identified and characterized to differentiate the rats with PAH from healthy controls, mostly assigned to acylcarnitines, phosphatidylcholines, sphingomyelin associated with the PAH development. Excitingly, RCE administration reversed high level of decadienyl-L-carnitine by the modulation of metabolic enzyme CPT1A in mRNA and protein level in serum and lung in the rats with PAH. Furthermore, RCE was observed to reduce autophagy, confirmed by significantly inhibited PPARγ, LC3B, ATG7 and upregulated p62, and inactivated LKB1-AMPK signal pathway. Notably, we accurately identified the constituents in RCE, and delineated the therapeutic mechansim that RCE ameliorated PAH through inhibition of fatty acid oxidation and autophagy. Altogether, RCE might be a potential therapeutic medicine with multi-targets characteristics to prevent the progression of PAH. This novel findings pave a critical foundation for the use of RCE in the treatment of PAH.

Background: A novel three-dimensional echocardiography (3DE)-derived strain analysis software specialized for right ventricular (RV) monitoring is emerging that could definitely evaluate RV free wall and interventricular septum longitudinal strain. The aim of this study was to compare the diagnostic performance in evaluating RV function between 3DE and two-dimensional echocardiography (2DE)-derived longitudinal strain.Methods: Echocardiographic examinations were performed in 82 patients with RV dysfunction associated with chronic left-sided heart failure and 40 control subjects. RV dysfunction was defined as a 3DE-derived RV ejection fraction (EF) Results: 3DE-derived peak systolic longitudinal strain of RV free wall (RV-fwLS) was significantly lower in patients with RV dysfunction compared to control subjects (-14.0±4.1 vs. -26.7±4.7%; pr=0.74, p-21.1% was most useful in identifying patients at higher risk of RV dysfunction (sensitivity: 90% and specificity: 85%), also higher than 2DE-derived strain parameters. Additionally, RV dysfunctional patients with pulmonary hypertension (PH) had significantly reduced 3DE-derived RV-fwLS value than the subgroup without PH (-13.1±3.8 vs. -15.0±4.2; pConclusion：Assessment of impaired RV systolic function by 3DE-derived longitudinal strain is better than 2DE in chronic left-sided heart failure patients with left ventricular EF

Based on detailed bonding analyses on the fluxional behaviors of planar B19- , tubular Ta@B20- , and cage-like B39- , we propose the concept of fluxional bonds in boron nanoclusters as an extension of the classical localized bonds and delocalized bonds in chemistry. © 2018 Wiley Periodicals, Inc.

Recent joint experimental and theoretical investigations have shown that seashell-like C2 B28 is the smallest neutral borospherene reported to date, while seashell-like Cs B29- (1-) as a minor isomer competes with its quasi-planar counterparts in B29- cluster beams. Extensive global minimum searches and first-principles theory calculations performed in this work indicate that with two valence electrons detached from B29-, the B29+ monocation favors a seashell-like Cs B29+ (1+) much different from Cs B29- (1-) in geometry which is overwhelmingly the global minimum of the system with three B7 heptagonal holes in the front, on the back, and at the bottom, respectively, unveiling an interesting charge-induced structural transition from Cs B29- (1-) to Cs B29+ (1+). Detailed bonding analyses show that with one less σ bond than B29- (1-), Cs B29+ (1+) also possesses nine delocalized π-bonds over its σ-skeleton on the cage surface with a σ + π double delocalization bonding pattern and follows the 2(n + 1)2 electron counting rule for 3D spherical aromaticity (n = 2). B29+ (1+) is therefore the smallest borospherene monocation reported to date which is π-isovalent with the smallest neutral borospherene C2 B28. The IR, Raman, and UV-vis spectra of B29+ (1+) are computationally simulated to facilitate its spectroscopic characterization.

Monocyclic Bn rings can act as n-electron σ-donors to stabilize a non-classical planar hypercoordinate atom at ring center, forming wheel-like structures. Herein, we report that BenHn rings can also serve as n-electron σ-donors to construct star-like structures including B©Be6H6+ and TM©Be7H7q (TM is a group 10–12 metal with q = −1, 0, and 1, respectively) by complying with octet or 18-electron rules. Electronic structure analyses show that these species are stabilized by the σ-donation and π-backdonation between the central atom and the peripheral BenHn ring, the favorable Coulomb attraction due to the negative–positive–negative charge population pattern on the central atom, the middle Ben layer, and the outer Hn layer, as well as the σ–π double aromaticity. Importantly, three of the ten species, including B©Be6H6+, Cu©Be7H7, and Au©Be7H7, were confirmed to be kinetically stable global minima, thereby providing promising targets for experimental preparations.

Shortly after the discovery of all-boron fullerenes D2d B40−/0 (borospherenes), the first axially chiral borospherenes C3/C2 B39− were characterized in experiments in 2015. Based on extensive global minimum searches and first-principles theory calculations, we present herein two new axially chiral members to the borospherene family: the aromatic cage-like C2 B34(1) and C2 B35+(2). Both B34(1) and B35+(2) feature one B21 boron triple chain on the waist and two equivalent heptagons and hexagons on the cage surface, with the latter being obtained by the addition of B+ into the former at the tetracoordinate defect site. Detailed bonding analyses show that they follow the universal bonding pattern of σ + π double delocalization, with 11 delocalized π bonds over a σ skeleton. Extensive molecular dynamics simulations show that these borospherenes are kinetically stable below 1000 K and start to fluctuate at 1200 K and 1100 K, respectively. The IR, Raman, and UV-vis spectra of 1 and 2 are computationally simulated to facilitate their experimental characterization.

Transition-metal doping leads to dramatic structural changes and results in novel bonding patterns in small boron clusters. Based on the experimentally derived mono-ring planar C9v Ta©B92- (1) and extensive first-principles theory calculations, we present herein the possibility of high-symmetry double-ring tubular D9d Ta@B183- (2) and C9v Ta2@B18 (3) and triple-ring tubular D9h Ta2@B27+ (4), which may serve as embryos of single-walled metalloboronanotube α-Ta3@B48(3,0) (5) wrapped up from the recently observed most stable free-standing boron α-sheet on a Ag(111) substrate with a transition-metal wire (-Ta-Ta-) coordinated inside. Detailed bonding analyses indicate that, with an effective dz2-dz2 overlap on the Ta-Ta dimer along the C9 molecular axis, both Ta2@B18 (3) and Ta2@B27+ (4) follow the universal bonding pattern of σ + π double delocalization with each Ta center conforming to the 18-electron rule, providing tubular aromaticity to these Ta-doped boron complexes with magnetically induced ring currents. The IR, Raman, and UV-vis spectra of 3 and 4 are computationally simulated to facilitate their future experimental characterization.

Boron has drawn intensive attention as a competitive anode candidate for next-generation high-energy rechargeable batteries. However, the large-scale application of boron anodes for practical batteries is still hindered by their electrochemical inertness caused mainly by the strong covalent bond in the aggregate boron backbone. Herein, quantum-sized boron dots (BQDs) were synthesized by the low-temperature liquid-phase exfoliation of boron nanosheets and incorporated into the conductive graphene matrix, consequently forming a 3D cross-linked BQDs/reduced graphene oxide (B@rGO) skeleton as high-performance anodes for lithium-ion batteries. Decreasing the size of boron to the quantum-sized scale vastly enables the electrochemical activity of boron as well as provides more active sites for ion insertion and extraction, thus increasing capacity and improving ion/charge diffusion and transfer. The 3D cross-linked conductive structure activates BQDs to store/release lithium reversibly, and endows the interrelated macroporous/mesopores, where the electrolyte can effortlessly access the conveying pathways and active sites for efficient Li+ adsorption and desorption. The developed anodes thus harvest remarkable electrochemical properties in terms of ultrahigh capacity of 2651 mAh g−1 at a current density of 0.05 A g−1, outstanding long-term cycling stability of 836 mAh g−1 at 0.1 A g−1 over 500 cycles, and excellent rate performance (even after enduring five consecutive current rates changing from 0.1 to 10 A g−1, it still delivers a capacity of 202 mAh g−1 at 10 A g−1). The protocol to boost the electrochemical performance by introducing BQDs could inspire wider explorations on other advanced anode materials.

The pore structural designability of wood-derived hard carbons (WDHCs) lays an optimal foundation for acquiring a cost-efficient and green anode material for sodium-ion batteries. Here, a WDHCs material was reported for high-capacity and cycling-stable sodium storage through a pore forming-opening strategy. Associated with the natural holey texture of wood, the WDHCs displays a hierarchical pore structure by a precise chemical treatment and a high-temperature carbonization, creating the straight channels and plentiful closed nanopores. This well-constructed channel structure is conducive to the penetration of electrolyte and the transport of sodium ions. The closed nanopores constructed by the curved graphene layers are gradually unfolded upon cycling, thus providing higher reversible capacity in the platform zone. The surface-controlled pseudocapacitive reaction favored ultrafast ion transport mainly contributes to sodium storage capacity. As a result, the developed optimal anodes harvest a high sodium storage capacity of 439 mAh g−1 at 0.1 A g−1, and excellent long-term cycling stability of 248 mA h g−1 at 0.1 A g−1 over 500 cycles as well as the capacity retention close to 100%. The galvanostatic intermittent titration technique combined with electrochemical impedance spectroscopy proved that the WDHCs anode has fast charge transport kinetics, thus exhibiting excellent rate performance.

Systematic experimental and theoretical studies have shown that anionic boron clusters (B-n(-)) possess planar or quasi-planar (2D) structures in a wide range of cluster size. The 2D structures consist of B-3 triangles often decorated with tetragonal and pentagonal defects. As n increases, hexagonal vacancies appear to be a key structural feature, which underlies the stability of borophenes. The correlation of the defects with cluster size is important to understand the stability and structural evolution of boron clusters. Here we report an investigation of the structures and chemical bonding of B-33(-) and B-34(-) using photoelectron spectroscopy (PES) and density functional theory (DFT) calculations. Global minimum searches reveal that the potential landscapes of B-33(-) and B-34(-) are dominated by 2D isomers. Comparisons between experiment and theory confirm that their global-minimum structures are both 2D with a hexagonal vacancy (C-s B-33(-)) and (C-1 B-34(-)), the latter being a chiral cluster. Bonding analyses indicate that the C-s B-33(-) cluster possesses ten delocalized bonds, analogous to those in the polycyclic aromatic hydrocarbon C19H11-. Bonding analyses on the equivalent closed-shell B-34(2-) species show that its 12 delocalized bonds consist of two separate aromatic systems: nine exterior and three interior bonds.

A B2-Ta@B18−tubular molecular rotor and a Ta@B20−boron drum with the record coordination number of twenty were observedviaa joint experimental and theoretical investigation.

Inspired by the recent discovery of the metal-centered tubular molecular rotor Cs B2-Ta@B18− with the record coordination number of CN = 20 and based on extensive first-principles theory calculations, we present herein the possibility of the largest tubular molecular rotors Cs B3-Ta@B18 (1) and C3v B4-Ta@B18+ (2) and smallest axially chiral endohedral metalloborospherenes D2 Ta@B22− (3 and 3′), unveiling a tubular-to-cage-like structural transition in metal-centered boron clusters at Ta@B22−via effective spherical coordination interactions. The highly stable Ta@B22− (3) as an elegant superatom, which features two equivalent corner-sharing B10 boron double chains interconnected by two B2 units with four equivalent B7 heptagons evenly distributed on the cage surface, conforms to the 18-electron configuration with a bonding pattern of σ + π double delocalization and follows the 2(n + 1)2 electron counting rule for spherical aromaticity (n = 2). Its calculated adiabatic detachment energy of ADE = 3.88 eV represents the electron affinity of the cage-like neutral D2 Ta@B22 which can be viewed as a superhalogen. The infrared, Raman, VCD, and UV-vis spectra of the concerned species are computationally simulated to facilitate their spectral characterizations.

The recently observed cage-like borospherenes D2d B40−/0 and C3/C2 B39− have attracted considerable attention in chemistry and materials science. Based on extensive global minimum searches and first-principles theory calculations, we present herein the possibility of cage-like Cs B39+ (1) and Cs B39+ (2) which possess five hexagonal and heptagonal faces and one filled hexagon and follow the bonding pattern of σ + π double delocalization with 12 delocalized π bonds over a σ-skeleton, adding two new members to the borospherene family. IR, Raman, and UV-vis spectra of Cs B39+ (1) and Cs B39+ (2) are computationally simulated to facilitate their experimental characterization.

As the first all-boron fullerene observed in experiments, cage-like borospherene B40 has attracted considerable attention in recent years. However, B40 has been proved to be chemically reactive and tends to coalesce with one another via the formation of covalent bonds. We explore herein the possibility of low-dimensional functional networks of B40 with effective transition-metal intercalations. We find that the four equivalent B7 heptagons on the waist of each B40 can serve as effective ligands to coordinate various transition metal centers in exohedral motifs. The intercalated metal atoms entail these networks with a variety of intriguing properties. The two-dimensional (2D) Cr2B40 network is a ferromagnetic metal while the 2D Zn2B40 network becomes semiconducting. In contrast, other 2D M2B40 (M = Sc, Ti, V, Mn, Fe, Co, Ni and Cu) networks and 1D CrB40 belong to nonmagnetic metals. The 3D Cr3B40 network is a magnetic metal. This work presents the viable possibility of assembling MnB40 metalloborospherenes into stable functional nanomaterials via effective transition-metal intercalations with potential applications in electronic and spintronic devices.

Size-selected boron clusters have been found to be predominantly planar or quasi-planar (2D) in the small size regime with the appearance of three-dimensional (3D) borospherene cages of larger sizes. A seashell-like B28− cluster was previously shown to be the smallest borospherene, which competes with a quasi-planar isomer for the global minimum. Here we report a study on the structures and bonding of the B29− and B29 clusters using photoelectron spectroscopy (PES) and first-principles calculations and demonstrate the continued competition between the 2D and borospherene structures. The PES spectrum of B29− displays a complex pattern with evidence of low-lying isomers. Global-minimum searches and extensive theoretical calculations revealed a complicated potential energy surface for B29− with five low-lying isomers, among which the lowest three were shown to contribute to the experimental spectrum. A 3D seashell-like Cs (2, 1A′) isomer, featuring two heptagons on the waist and one octagon at the bottom, is the global minimum for B29−, followed by a 2D C1 (3, 1A) isomer with a hexagonal hole and a stingray-shaped 2D Cs (1, 1A′) isomer with a pentagonal hole. However, by taking into account the entropic effects, the stingray-shaped isomer 1 was shown to be the lowest in energy at room temperature and was found to dominate the PES spectrum. Isomers 2 and 3, which have lower electron binding energies, were also found to be present in the experiment. Chemical bonding analyses showed that isomer 1 is an all-boron analogue of benzo[ghi]fluoranthene (C18H10), whereas the borospherene isomer 2 possesses 18π electrons, conforming to the 2(N + 1)2 electron counting rule for spherical aromaticity. For the B29 neutral cluster, the seashell-like borospherene isomer is the global minimum, significantly lower in energy than the stingray-shaped quasi-planar structure.

Based on extensive first-principles theory calculations, we present the possibility of an endohedral charge-transfer complex, Cs Ca@B37(-) (), which contains a 3D aromatic fullerene-like Cs B37(3-) () trianion composed of interwoven boron double chains with twelve delocalized multicenter π bonds (12 mc-2e π, m = 5, 6) over a σ skeleton, completing the Bn(q) borospherene family (q = n - 40) in the size range of n = 36-42.

Based on extensive first-principles theory calculations, we present the possibility of construction of the Saturn-like charge-transfer complexes Li4&B36 (2), Li5&B36+ (3), and Li6&B362+ (4) all of which contain a perfect cage-like B364− (1) core composed of twelve interwoven boron double chains with a σ + π double delocalization bonding pattern, extending the Bnq borospherene family from n = 38–42 to n = 36 with the highest symmetry of Th.

Detailed molecular orbital and bonding analyses reveal the existence of both fluxional σ- and π-bonds in the global minima C

Transition-metal doping leads to dramatic structural changes and results in novel bonding patterns in small boron clusters. Based on the experimentally derived mono-ring planar C9v Ta©B92- (1) and extensive first-principles theory calculations, we present herein the possibility of high-symmetry double-ring tubular D9d Ta@B183- (2) and C9v Ta2@B18 (3) and triple-ring tubular D9h Ta2@B27+ (4), which may serve as embryos of single-walled metalloboronanotube α-Ta3@B48(3,0) (5) wrapped up from the recently observed most stable free-standing boron α-sheet on a Ag(111) substrate with a transition-metal wire (-Ta-Ta-) coordinated inside. Detailed bonding analyses indicate that, with an effective dz2-dz2 overlap on the Ta-Ta dimer along the C9 molecular axis, both Ta2@B18 (3) and Ta2@B27+ (4) follow the universal bonding pattern of σ + π double delocalization with each Ta center conforming to the 18-electron rule, providing tubular aromaticity to these Ta-doped boron complexes with magnetically induced ring currents. The IR, Raman, and UV-vis spectra of 3 and 4 are computationally simulated to facilitate their future experimental characterization.

Based on detailed bonding analyses on the fluxional behaviors of planar B

Monocyclic B

The newly discovered borospherenes B40 (-/0) and B39 (-) mark the onset of a new class of boron nanostructures. Based on extensive first-principles calculations, we introduce herein two new chiral members to the borospherene family: the cage-like C1 B41 (+) (1) and C2 B42 (2+) (2), both of which are the global minima of the systems with degenerate enantiomers. These chiral borospherene cations are composed of twelve interwoven boron double chains with six hexagonal and heptagonal faces and may be viewed as the cuborenes analogous to cubane (C8 H8 ). Chemical bonding analyses show that there exists a three-center two-electron σ bond on each B3 triangle and twelve multicenter two-electron π bonds over the σ skeleton. Molecular dynamics simulations indicate that C1 B41 (+) (1) fluctuates above 300 K, whereas C2 B42 (2+) (2) remains dynamically stable. The infrared and Raman spectra of these borospherene cations are predicted to facilitate their experimental characterizations.

Considerable recent research effort has been devoted to the development of boronyl (BO) chemistry. Here we predict three perfectly planar boron boronyl clusters: C2v B6O4 (1, (1)A1), D2h B6O4(−) (2, (2)B3u), and D2h B6O4(2−) (3, (1)Ag). These are established as the global-minimum structures on the basis of the coalescence kick and basin hopping structural searches and electronic structure calculations at the B3LYP/aug-cc-pVTZ level, with complementary CCSD/6-311+G* and single-point CCSD(T)/6-311+G*//B3LYP/aug-cc-pVTZ calculations for 2. The C2v B6O4 neutral cluster features a hexagonal B4O2 ring with two terminal BO groups. The D2h B6O4(−/2−) clusters have ethylene-like structures and are readily formulated as B2(BO)4(−/2−), in which a B2 core with double bond character is bonded to four terminal BO groups. Chemical bonding analyses show that B6O4 (1) possesses an aromatic π bonding system with three delocalized, six-centered π bonds over the hexagonal ring, rendering it an inorganic analogue of benzene, whereas the B6O4(−/2−) (2 and 3) species closely resemble ethylene in terms of structures and bonding. This work provides new examples for the analogy between boron oxides and hydrocarbons.

Inspired by the recent discovery of the metal-centered tubular molecular rotor C

With inspirations from recent discoveries of the cage-like borospherene B40 and perfectly planar Co ∈ B18− and based on extensive global minimum searches and first-principles theory calculations, we present herein the possibility of the novel planar Ni ∈ B18 (1), cage-like heteroborospherenes Nin ∈ B40 (n = 1–4) (2–5), and planar heteroborophenes Ni2 ∈ B14 (6, 7) which all contain planar or quasi-planar heptacoordinate transition-metal (phTM) centers in η7-B7 heptagons. The nearly degenerate Ni2 ∈ B14 (6) and Ni2 ∈ B14 (7) monolayers are predicted to be metallic in nature, with Ni2 ∈ B14 (6) composed of interwoven boron double chains with two phNi centers per unit cell being the precursor of cage-like Nin ∈ B40 (n = 1–4) (2–5). Detailed bonding analyses indicate that Nin ∈ B40 (n = 1–4) (2–5) and Ni2 ∈ B14 (6, 7) possess the universal bonding pattern of σ + π double delocalization on the boron frameworks, with each phNi forming three lone pairs in radial direction (3dz22, 3dzx2, and 3dyz2) and two effective nearly in-plane 8c-2e σ-coordination bonds between the remaining tangential Ni 3d orbitals (3dx2−y2 and 3dxy) and the η7-B7 heptagon around it. The IR, Raman, and UV-vis absorption spectra of 1–5 are computationally simulated to facilitate their experimental characterizations.

The recently observed cage-like borospherenes D

A tubular molecular rotor B

Size-selected boron clusters have been found to be predominantly planar or quasi-planar (2D) in the small size regime with the appearance of three-dimensional (3D) borospherene cages of larger sizes. A seashell-like B

The recent discovery of perfect cage-like D 2d B40 − and D 2d B40 (all-boron fullerenes) has led to the emergence of a borospherene family. However, the geometrical and electronic structures of their cationic counterpart B40 +, previously detected in gas phase, remain unknown to date. Based on extensive first-principles theory calculations, we present herein the possibility of a perfect cage-like D 2d B40 + (1) (2A1) for the monocation, which turns out to be the global minimum of the system similar to B40 − and B40, adding a new member to the borospherene family. Molecular dynamics simulations indicate that D 2d B40 + (1) is dynamically stable at 300 K, whereas it starts to fluctuate at 500 K between the two lowest-lying isomers D 2d B40 + (1) (W) and C s B40 + (3) (M) in concerted W-X-M mechanisms via the transition state of C 1 B40 + (X), with forward (W → X → M) and backward (M → X → W) activation energies (Ea) of 14.6 and 6.9 kcal mol−1, respectively. The spectra from IR, Raman, and UV–vis analyses were simulated to facilitate future characterization of this important borospherene monocation.

Based on extensive first-principles theory calculations, we present the possibility of construction of the Saturn-like charge-transfer complexes Li4B36 (2), Li5B36(+) (3), and Li6B36(2+) (4) all of which contain a perfect cage-like B36(4-) (1) core composed of twelve interwoven boron double chains with a σ + π double delocalization bonding pattern, extending the Bn(q) borospherene family from n = 38-42 to n = 36 with the highest symmetry of T(h).

Based on extensive global-minimum searches and first-principles electronic structure calculations, we present the viability of an endohedral metalloborospherene Cs Ca@B38 () which contains a Cs B38(2-) () dianion composed of interwoven boron double chains with a σ + π double delocalization bonding pattern, extending the Bn(q) (q = n - 40) borospherene family from n = 39-42 to n = 38. Transition metal endohedral complexes Cs M@B38 (M = Sc, Y, Ti) (, , ) based on Cs B38(2-) () are also predicted.

Using the newly discovered borospherenes C3 B39(-) and C2 B39(-) as molecular devices and based on extensive global-minimum searches and first-principles calculations, we present herein the possibility of the first axially chiral metalloborospherenes C3 Ca@B39(+) (, (1)A) and C2 Ca@B39(+) (, (1)A), which are the global minimum and the second lowest-lying isomer of CaB39(+), respectively. These metalloborospherene species turn out to be charge-transfer complexes Ca(2+)@B39(-) in nature, with the Ca centre on the C3 or C2 molecular axis donating one electron to the B39 cage which behaves like a superhalogen. Molecular orbital analyses indicate that C3/C2 Ca(2+)@B39(-) possess the universal bonding pattern of σ plus π double delocalization, similar to their C3/C2 B39(-) parents. Molecular dynamics simulations show that both C3 Ca@B39(+) () and C2 Ca@B39(+) () are dynamically stable at 200 K, with the former starting to fluctuate structurally at 300 K and the latter at 400 K, again similar to C3/C2 B39(-). The infrared and Raman spectra of C3/C2 Ca@B39(+) (/) are simulated and compared with those of C3/C2 B39(-) to facilitate their forthcoming experimental characterization.

Chirality plays an important role in chemistry, biology, and materials science. The recent discovery of the B40(-/0) borospherenes marks the onset of a class of boron-based nanostructures. Here we report the observation of axially chiral borospherene in the B(39)(-) nanocluster on the bases of photoelectron spectroscopy, global minimum searches, and electronic structure calculations. Extensive structural searches in combination with density functional and CCSD(T) calculations show that B(39)(-) has a C3 cage global minimum with a close-lying C2 cage isomer. Both the C3 and C2 B(39)(-) cages are chiral with degenerate enantiomers. The C3 global minimum consists of three hexagons and three heptagons around the vertical C3 axis. The C2 isomer is built on two hexagons on the top and at the bottom of the cage with four heptagons around the waist. Both the C3 and C2 axially chiral isomers of B(39)(-) are present in the experiment and contribute to the observed photoelectron spectrum. The chiral borospherenes also exhibit three-dimensional aromaticity, featuring σ and π double delocalization for all valence electrons. Molecular dynamics simulations reveal that these chiral B(39)(-) cages are structurally fluxional above room temperature, compared to the highly robust D(2d)B40 borospherene. The current findings add chiral members to the borospherene family and indicate the structural diversity of boron-based nanomaterials.

To summarize the outcomes of surgical treatment of 568 cleft palate patients.568 cleft palate patients of different age, gender were operated with the help of high-frequency electric knife. Iodoform gauze packing or absorbable hemostatic gauze was used on both sides of the relaxation incision. After surgery, the diet, temperature changes, wound healing and bleeding, postoperative cleft or perforation were observed and analyzed.Postoperative infection was not found in all cases. 24 patients had fever, most of them used iodoform gauze packing on both sides of the relaxation incision, returned to normal diet in longer time. 8 patients developed bleeding and 13 had postoperative cleft or perforation.It is suggested that intraoperative high-frequency electric knife can be used for cleft palate surgery to reduce the amount of bleeding,the use of absorbable hemostatic gauze is more helpful for wound healing and postoperative recovery.