Laser Ablation Atomic Beam Apparatus with Time-Sliced Velocity Map Imaging for Studying State-to-State Metal Reaction Dynamics

We report a newly constructed laser ablation crossed molecular beam apparatus, equipped with time-sliced velocity map imaging technique, to study state-to-state metal atom reaction dynamics. Supersonic metal atomic beam is generated by laser vaporization of metal rod, and free expansion design without gas flow channel has been employed to obtain a good quality of metal atomic beam. We have chosen the crossed-beam reaction Al＋O2 to test the performance of the new apparatus. Two-rotational-states selected AIO（X^2∑＋, v=0, N and N＋I4） products can be imaged via P（N） and R（N＋14） branches of the Av=l band at the same wavelength, during （1＋1） resonance-enhanced multi-photon ionization through the AIO（D2E＋） intermediate state. In our experiment at 244.145 nm for simultaneous transitions of P（15） and R（29） branch, two rings in slice image were clearly distinguishable, corresponding to the AiO（v=0, N=IS） and AIO（v=0, N=29） states respectively. The energy difference between the two rotational levels is 403 cm^-1. The success of two states resolved in our apparatus suggests a better collisional energy resolution compared with the recent research study [J. Chem. Phys. 140, 214304 （2014）].

Theoretical Study on the Dehydrogenation Reaction of H_2S by VS^+ (~3Σ^-)

The dehydrogenation reaction of H2S by the ^3Σ^- ground state of VS^＋： VS^＋ ＋ H2S → VS2^＋ ＋ H2 has been studied by using Density Functional Theory （DPT） at the B3LYP/DZVP level. It is found that the reaction proceeds along two possible pathways （A and B） yielding two isomer dehydrogenation products VS2^＋-1 （^3B2） and VS2^＋-2 （^3A1）, respectively. For both pathways, the reaction has a two-step-reaction mechanism that involves the migration of two hydrogen atoms from S2 to V^＋, respectively. The migration of the second hydrogen via TS3 and that of the first via TS4 are the rate-determining steps for pathways A and B, respectively. The activation energy is 17.4 kcal/mol for pathway A and 22.8 kcal/mol for pathway B relative to the reactants. The calculated reaction heat of 9.9 kcal/mol indicates the endothermicity of pathway A and that of -11.9 kcal/mol suggests the exothermicity of pathway B.

Controlling Metalation Reaction of Phthalocyanine with Cobalt at Single-Molecule Level on Au(111)Surfac

Metalation reac-tion of metal-free phthalocyanine molecule with Co atom adsorbed on Au(111)surface has been studied in situ at single atom/molecule scale by low-temperature scanning tunneling microscopy(STM)experiment combined with simulations based on density function theory calculations.Through manipulations using STM tip,we showed a controlled manner to have a single metal-free phthalocyanine molecule react with a Co atom to form Co phthalocyanine molecule.In this reaction process,an intermediate state originating from π-d interaction between the metal-free phthalocyanine molecule and Co atom has been identi ed.Moreover,we also revealed that the redox reaction represented as bond breaking and bond forming relative to the Co and pyrrolic N atoms,not pyrrolic H atoms,is a key process for dehydrogenation and metalation reaction.Our DFT calculations provided theoretical supporting for the above conclusions,and further understanding of the related mechanisms.

Advanced Techniques for Quantum-State Specific Reaction Dynamics of Gas Phase Metal Atoms

One of the themes of modern molecular reac tion dynamics is to charac terize elementary chemical reactions from“quan tum state to quan tum stat e”,and the study of molecular reaction dynamics in excited states can help test the validi ty of modern chemical t heories and provide met hods to cont rol chemical reactions.The subject of this review is to describe the recent experimental techniques used to study the reaction dynamics of metal atoms in the gas phase.Through these techniques,information such as the internal energy distribution and angular distribution of the nascent products or the three-dimensional stereodynamic reactivity can be obtained.In addition,by preparing metal at oms wi th specific exci ted elec tronic states or orbi tal arrangemen ts,information about the reactivity of the electronic states enriches the relevant understanding of the electron transfer mechanism in metal reaction dynamics.

Imaging Reaction Dynamics of Y+SO2

The reaction dynamics of yttrium atoms with sulfur dioxide molecules at a high collision energy of 36 kcal/mol was studied using time-sliced velocity map ion imaging,crossed molecular beam and laser-ablation method.The product YO was detected via multiphoton ionization at various wavelengths in the region of 482-615 nm.The slice images of YO show a broad velocity distribution and forward-backward peaking angular distribution.The forward scattering signal is stronger than its backward distribution.This indicates that the reaction proceeds via an intermediate complex and the lifetime of the intermediate state is less than one rotational period.The formation of complex suggests that electron transfer occurs in the oxidation reaction.

THE STUDY ON TRE KINETICS AND MECHANISM OF THE REACTIONS OF METAL IONS WITH PnAO

The kinetics and the mechanism of the formation reactions of M(PnAO)^(2+)(M=Ni,Co,Cu)were studied with UV Spectrophotometer and Stopped Flow Spectrophotometer and a three steps mechanism was suggested.

STUDIES ON THE PROPERTIES OF SCHIFF BASE TYPE ARYLMERCURY COMPOUNDS Ⅲ TRANSMETALLATION REACTION OF SCHIFF BASE TYPE ARYLMERCURY COMPOUNDS WITH METALLIC TIN

The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ) to give dichlorobisaryltin(Ⅳ).The ~1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.

C(sp^2)-H/O-H cross-dehydrogenative coupling of quinoxalin-2(1H)-ones with alcohols under visible-light photoredox catalysis

An efficient and practical route to various 3-alkoxylquinoxalin-2(1 H)-ones through visible-light photocatalytic C(sp^2)-H/O-H cross-dehydrogenation coupling of quinoxalin-2(1 H)-ones and alcohols,employing ambient air as an oxidant at room temperature under metal-free conditions,was developed.

A Metal-organic Framework Containing Octanuclear Zn(Ⅱ) Clusters Constructed by 5-Methoxyisophthalate and Flexible Bis(imidazolyl) Ligand

The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-organic framework containing octanuclear Zn（II） units, [Zn4（MeO-ip）3（OH）2（bmip）]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348（3）, b = 14.163（4）, c = 15.088（4） , α = 108.537（2）, β = 106.542（2）, γ = 103.106（1）o, V = 2065.4（9） -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-（-3）, μ = 2.375 mm-（-1）, S = 1.015, F（000） = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections（I 〉 2σ（I））. The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.

ABSTRACTS——From Journal of Iron and Steel Research(in Chinese)

The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltage was applied between melt and slag. The bigger the contact area of the conductor with melts is, the faster the reaction rate is. With the increase of applied voltage which is beneficial for electron's migration between metal and slags, the rate and extent of reaction increase.

Template-assisted synthesis of hierarchically porous Co3O4 with enhanced oxygen evolution activity

Oxygen evolution reaction（OER） is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells（URFCs）. However, the kinetically sluggishness of OER and the high prices as well as the scarcity of the most active precious metal electrocatalysts are the major bottleneck in these devices. Developing low-cost non-precious metal catalysts with high activity and stability for OER is highly desirable. A facile, in situ template method combining the dodecyl benzene sulfuric acid sodium（SDBS） assisted hydrothermal process with subsequent high-temperature treatment was developed to prepare porous Co3O4 with improved surface area and hierarchical porous structure as precious catalysts alternative for oxygen evolution reaction（OER）. Due to the unique structure, the as-prepared catalyst shows higher electrocatalytic activity than Co3O4 prepared by traditional thermal-decomposition method（noted as Co3O4-T） and commercial IrO2 catalyst for OER in 0.1M KOH aqueous solution. Moreover, it displays improved stability than Co3O4-T. The results demonstrate a highly efficient, scalable, and low cost method for developing highly active and stable OER electrocatalysts in alkaline solutions.

Hypervalent Iodine(Ⅲ)-Mediated Benzannulation of Enamines with Alkynes: an Efficient Synthesis of Substituted Aminonaphthoic Acid Derivatives

An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-ful substituted 1-amino-2-naphthoic acid derivatives via benzannulation reactions.Various N-unsubstituted and N-alkyl substituted aromatic enamines with terminal alkynes and non-terminal alkynes can be converted into corre-sponding 1-amino-2-naphthoic acid derivatives under mild reaction conditions.When meta-substituted phenyl enamines were employed in the reaction,two cyclization paths were detected in the reaction and ortho-cyclization products were the only or major products.Good functional group tolerance,readily available material and high atom utilization efficiency make this method a potential procedure which may find broad application in organic synthesis.

Mild hydrothermal preparation of a layered metal hydroxide salt with microtube/rod morphology

Microtubes/rods of the layered metal hydroxide salt compound Cd2（OH）3（DS）·nH2O, where DS stands for dodecyl sulfate sandwiched between two adjacent inorganic sheets, have been synthesized for the first time through a mild hydrothermal reaction route. The microtubes/rods have a diameter of about 1 μm and a length ranging from several microns to 20μm. The growth process of microtubes/rods under the experimental conditions employed follows a dissolution-recrystallization route.

Cobalt Doped Titanate Nanotubes：Synthesis and Properties

Cobalt oxide doped titanate nanotubes are synthesized with a simple hydrothermal treatment of mixed Co3O4 and TiO2 powders. The formed tubular nanostructure, chemical composition,and the elemental distribution are analyzed using TEM, BET, FTIR, XRD, and XPS. The electrocatalytic activity towards oxygen evolution reactions and photodegradation against Rhodamine B are investigated. It has been found out that the oxygen evolutions starts at 0.8 V and reaches 0.98 mA ·cm^-1 at 1.4 V vs. SCE. For photodegradation of Rhodamine B, the concentration decreased to 24% after 1 h irradiation using the sample with a mass percentage of 5% cobalt. The results demonstrate that the cobalt oxide doped titanate nanotubes are good candidates as electrocatalysts and photocatalytic materials.