Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on <i>ortho</i>-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazine

Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on ortho-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazin

Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on <i>ortho</i>-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazine

Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on ortho-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazin

Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on <i>ortho</i>-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazine

Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on ortho-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazin

Unveiling the Au Surface Reconstruction in a CO Environment by Surface Dynamics and Ab Initio Thermodynamics

Surface reconstruction changes the atomic configuration of the metal surface and thus alters its intrinsic physical and chemical properties. Recent in situ experiments have shown a variety of surface reconstructions under reaction conditions, but how to effectively predict and characterize these structures remains challenging. Herein, we combine a DFT-based kinetic Monte Carlo simulation method and ab initio thermodynamics to explore the low-energy configurations of metal surface reconstructions, which takes the surface dynamics under the reactive environment into account. We systematically simulate 13 Au surfaces ((100), (110), (111), (210), (211), (221), (310), (311), (320), (321), (322), (331), and (332)) in the CO environment and identify 19 candidate reconstruction patterns driven by CO adsorption. The breakup of the original surfaces is attributed to the lateral interactions among the nearest-neighboring adsorbates. This work provides an efficient approach to unveil the reconstructed metal surface structures in reactive environments for guiding the experiments

Unveiling the Au Surface Reconstruction in a CO Environment by Surface Dynamics and Ab Initio Thermodynamics

Surface reconstruction changes the atomic configuration of the metal surface and thus alters its intrinsic physical and chemical properties. Recent in situ experiments have shown a variety of surface reconstructions under reaction conditions, but how to effectively predict and characterize these structures remains challenging. Herein, we combine a DFT-based kinetic Monte Carlo simulation method and ab initio thermodynamics to explore the low-energy configurations of metal surface reconstructions, which takes the surface dynamics under the reactive environment into account. We systematically simulate 13 Au surfaces ((100), (110), (111), (210), (211), (221), (310), (311), (320), (321), (322), (331), and (332)) in the CO environment and identify 19 candidate reconstruction patterns driven by CO adsorption. The breakup of the original surfaces is attributed to the lateral interactions among the nearest-neighboring adsorbates. This work provides an efficient approach to unveil the reconstructed metal surface structures in reactive environments for guiding the experiments

High or Low Coordination: Insight into the Active Site of Pt Nanoparticles toward CO Oxidation

The catalytic activity of metal nanoparticles (NPs) is highly dependent on the coordination environment of the surface sites. Understanding the role of different sites in reactions is essential for gaining insights into catalytic activity and the precise design of catalysts. Herein, we used first-principles calculation-based kinetic Monte Carlo simulations to investigate correlations between different sites on Pt NPs in CO oxidation reactions. Low-coordinated (LC) sites favor the CO adsorption and reaction, whereas the oxygen mainly adsorbs on high-coordinated (HC) sites and diffuses to LC sites for reaction at low temperatures. Compared with step-dominated and terrace-dominated structures, the step-terrace structures exhibit higher activities. This reveals that the catalytic performance is not simply determined by the sites where the reaction occurs but is dramatically affected by the kinetic synergies between different sites. A proper way to optimize the activity of Pt catalysts is to balance the LC and HC sites

Temporal variations of predawn (Ψ_p) and midday (Ψ_m) leaf water potential for plants at the control and treatment plots.

A.S and A.T represent A. splendens and Allium tanguticum, respectively. Asterisks (*) located above Ψp or below Ψm comparisons on each date indicate significant differences between A.S and A.T using t-test comparisons at p<0.05.</p

Statistics of <i>de novo</i>, MUTT, ADTT, CMUTT and CADTT assemblies.

<p>≥1 time is a combination of “ACE1” and “AC>1”.^a Aligned concordantly </p><p>^b Overall alignment rate.</p><p>% level. Different lower case letters within this column indicates that the means were significantly different at the 5</p

Dimethylsulfoxide-induced trinuclear Co(II) and Ni(II) salamo-type complexes: Syntheses, crystal structures and spectral properties

<p></p> <p>Two homotrinuclear Co(II) and Ni(II) complexes, [{CoL(OAc)(DMSO)}₂Co]·2DMSO and [{NiL(OAc)(DMSO)}₂Ni] have been synthesized by the reaction of 4,4′-dichloro<b>-</b>2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol (H₂L) with cobalt(II) and nickel(II) acetate tetrahydrate in the solution of DMSO, respectively, and characterized by elemental analyses, IR, UV–Vis spectra and X-ray crystallography. In the Co(II) complex, terminal Co2 and Co2^#1 atoms located in the N₂O₂ sites, and are both hexa-coordinated with slightly distorted octahedral geometries. While the central Co1 atom is also hexa-coordinated by six oxygen atoms, four are phenoxy oxygen atoms from two (L)²⁻ units, and two oxygen atoms from <i>µ</i>₂-acetate ions, which has formed a octahedral geometry. In the Ni(II) complex, coordination environments of the Ni(II) atoms are similar to those of the Co(II) atoms. Infinite 1D supramolecular structure is formed via abundant intermolecular hydrogen bonding interactions in the Co(II) complex.</p

[2]Pseudorotaxanes and [2]Catenanes Constructed by Oxacalixcrowns/Viologen Molecular Recognition Motifs

Oxacalix­[2]­arene­[2]­pyrazine and functional polyether derived oxacalixcrown-6, -7, and -8 were synthesized, and their host–guest complexation with paraquat to form [2]­pseudorotaxanes was studied. The [2]­pseudorotaxanes were then successfully used in the construction of two oxacalixcrown-tetracationic cyclophane [CBPQT⁴⁺] based [2]­catenanes