Theoretical Studies on Adsorption and Diffusion of Hydrogen Atom on Pd（311） and Ni（311） Stepped Surface

The adsorption and diffusion of hydrogen atom on open rough Pd(311) and Ni(311) stepped surface were investigated in detail using 5-parameter Morse Potential (5-MP for short) method. The results on theoretical studies indicate that only threefold adsorption states exist at low coverage, and fourfold states are annihilated on the top layer which become the diffusion channels between threefold adsorption states due to strong competition and repulsion between hydrogen adatoms.     

Octa-membered Water Ring Chain Based on Sulfonic Group in Ni（Ⅱ） Complex with 2-[（E）-（2-Oxidophenyl）methyleneamino] Ethanesulfonato and 2,2＇-Bipyridinyl

The title compound, [Ni（tssb）（2,2-bipy）2].5（H2O） 1 （tssbH2 =2-[（E）-（2-oxido- phenyl）methyleneamino]ethanesulfonato, 2,2-bipy = 2,2＇-bipyridinyl）, belongs to orthorhombic, space group Pbcn with a = 20.3983（18）, b = 17.6929（15）, c = 17.0897（15） nm, V= 6167.8（9） nm^3, Mr= 688.38, Z = 8, De = 1.481 g.cm^-3, F（000） = 2880,μ = 0.758 mm-1 and S =1.099. Each NiIr atom is six-coordinated by one N and one O atoms from one tssb^2- anion and four N atoms from two 2,2-bipy ligands to give a distorted octahedral geometry. Noticeably, there exists a rare octa-mem- bered water ring which presents a 1D chain by sulfonic group.     

[NiCl（Ph2PCH2CH2OH）2Cl·H2O]^＋Cl^-和[Ni（Ph2P（O）CH2CH2OH）4]^2＋[NiCl4]^2-的合成及晶体结构

通过NiCl2.6H2O与双齿配体2-（二苯基膦）乙醇（Ph2PCH2CH2OH）或其氧化物2-（二苯基氧膦）乙醇[Ph2P（O）CH2CH2OH]的反应,制得两种结构新颖的阳离子型镍配合物[NiCl（Ph2PCH2CH2OH）2（H2O）]^＋Cl^-（1）和[Ni（Ph2P（O）CH2CH2OH）4]^2＋[NiCl4]^2-（2）.通过元素分析、31P核磁共振及X射线单晶衍射对配合物1和2的结构进行了表征.配合物1的晶体属单斜晶系,C2/c空间群,中心金属Ni具有六配位八面体几何构型.配合物2属四方晶系,I4（1）/a空间群,中心原子Ni与P＝＝O基团中的O配位形成平面四边形构型.     

Studies on Effect of Tri(2-hydroxypropyl), Tri(2-hydroxybutyl) and Tri(hydroxythiodiethylene) Borates on Thermal and Heat Properties of Rigid Polyurethane-Polyisocyanurate Foams

Effect of tri（2-hydroxypropyl）, tri（2-hydroxybutyl）and tri（hydroxythiodiethylene） borates （BT2HB, BT2HP and BTHET） on the thermal and heat properties of the rigid polyurethane-polyisocyanurate （PUR-PIR） foams was investigated： Increasing amounts of BT2HB and BT2HP in the foam composition, from 0.05 to 0.4 of chemical equivalent, caused increases in the softening point, the temperature of the first mass loss, the extrapolated tempera- ture of the main mass loss foam and temperature of the highest rate of the mass loss. In the case when BTHTE was added to the foam compositions, the lower increase in the mentioned above characteristic temperatures was observed as compared to those of standard foam （without borate added）.     

Dimerization of Propylene by Nickel （II） and Cobalt （II） Catalysts Based on Bidentate Nitrogen-phosphino Chelating Ligands

The catalytic property of propylene dimerization by several nickel (II), cobalt (II) complexes containing N-P bidentate ligands was studied in combination with organoaluminum co-catalysts. The effects of the type of aluminum co-catalysts and its relative amount, the nature of precursors in terms of ligand backbone and metal center were investigated. The results indicated that precursor I (N,-N-dimethyl-2-(diphenylphosphino)aniline nickel (II) dichloride)exhibited high activity in propylene dimerization in the presence of the strong Lewis acid Et3A12Cl3, whereas low productivity by its cobalt analogues was observed under identical reaction conditions.     

Topography Structure and Scanning Tunneling Spectrum of Nickel（Ⅱ）-tetraphenylporphyrin Molecules on Au（111）

1 INTRODUCTION Metalloporphyrins are intensively studied for many reasons. They have been comprehensively used in biochemistry, analytical chemistry and so on. They play an important role in biological processes such as oxygen transport photosynthesis and enzyme catalysis. They can act as catalysts[1], and can undergo reversible redox reactions in which the site of electron transfer may be localized on the por- phyrin ring or on the central metal ion. Both reaction types are important in…     

Chiral and Achiral Bis（2-oxazolinylphenolato）nickel（Ⅱ） Complexes-Synthesis, Crystal Structure, and Catalytic Properties

Introduction Oxidation was a very important reaction both in synthetic pathways and in industrial processes. Metal-catalyzed oxidation provided excellent alternatives in synthetic processes. However, molecular oxygen has been applied only in a limited number of metal-catalyzed oxidations, because it was very difficult to activate molecular oxygen and most of transition metal complexes were sensitive to oxygen. It was noted that metal-catalyzed Baeyer-Villiger oxidation was a convenient method…     

Comparative Studies on Mass Spectrometric Fragmentation of Linear Chiral Secondary Alcohols （ R ） -1-（4-Alkylphenyl） and （ R ） -1- （ 4-Alkoxyphenyl/Alkylthiophenyl ） Alcohols

Introduction Chiralsecondaryalcoholsareveryimportantinter mediatesinorganicsynthesis.Theyaregenerallypre paredviachemicalorenzymaticresolutionofracemic secondaryalcohols[1—4],chemicalorenzymaticasym metricreductionofprochiralketones[5—7],andasym metrica…     

Syntheses, Characterization and Crystal Structures of New Nickel Complexes with 2,6-Bis （ imino ） pyridyl Ligands

In the past decade, the imino-complexes based on late transition metal have received significantly increasing attention for their excellent performance in the olefin polymerization area since Brookhart et al. demonstrated that the Ni( Ⅱ ) complexes incorporating with sterically hindered α-diimine ligands could be used in the polymerization of ethylene to form high molecular weight polymers.     

Oxygen Atom Adsorption and Diffusion on Pd Low-index Surfaces and （311） Stepped Surface

Introduction Atom adsorption on transition metal surfaces has attracted special attention as a base for understanding the fundamental processes of oxidative catalysis. Particularly interesting is the adsorption and diffusion of oxygen on well-defined metal surfaces. An oxygen covered palladium surface, for example, plays a central role in several important reactions such as oxidation of carbon monoxide and ammonia. In particular, the (100), (111), (110) surfaces and the interactions with oxyge…     

Adsorption and Diffusion of O Atoms on Ag（210） Stepped Surface

The O-Ag(210)surface adsorption system was studied via the five-parameter Morse potential theory.Meanwhile,the 2O-Ag(210)system was investigated via the extended London-Eyring-Polanyi-Sato(LEPS)potential theory to learn the interaction between the adsorption states.Calculated results demonstrate that there are two stable on-surface adsorption sites(B and H)for O atoms on Ag(210)stepped surface.And the perpendicular vibrations are 30.3 and 42.9 meV,which are close to that observed in high resolution electron energy loss spectroscopy(HREELS).Also,there exists an octahedral subsurface adsorption state with a high vibrational frequency,and the interaction between the on-surface and subsurface O species is slight.The mode at 54.6 meV,which is close to that observed in HREELS(54-56 meV),is because of the vibration of the O atom on B site under the influence of that on H site.     

H原子在W低指数面上的吸附位和吸附态

应用原子和表面簇合物相互作用的5参数Morse 势及由5参数Morse势组装推广的LEPS方法对H-W低指数表面吸附体系进行了研究, 并获得了全部临界点特性. 计算结果表明, 低覆盖度下, H原子优先吸附在W(100)面的内层吸附位二层桥位B', 获得156 meV的垂直振动频率, 随着覆盖度的增加, H原子稳定吸附在表层的五重洞位(二层顶位)、桥位及顶位. 内层吸附位的优先吸附, 对与其邻近的表面吸附位的临界点性质有一定影响. 在W(110)面上只存在三重洞位的稳定吸附态, 垂直振动频率为151 meV. 在W(111)面上存在三种稳定吸附态, 子表面吸附位H₁, 桥位B'和顶位T, 分别获得104, 200, 259 meV的垂直振动频率. 在低覆盖度下, H原子优先吸附在子表面吸附位H₁.     

H原子在Ru(1121)台阶面上的吸附位和吸附态

利用原子和表面簇合物相互作用的五参数Morse势方法(简称5-MP)研究了H-Ru(1121)台阶面吸附体系,并利用推广的LEPS方法研究了2H-Ru(1121)体系,探讨了表面吸附态之间的相互作用.研究结果表明,H原子在开放的Ru(1121)台阶面表面上的晶胞存在4种不等价的表面三重吸附态.还存在两类与表面有直接扩散通道的内层吸附态.理论分析表明,TDS实验出现的α态是与内层吸附态有强相互作用的强排斥表面吸附态,β态为弱排斥表面吸附态,而γ态为与内层吸附态无相互作用的表面吸附态.实验上将α态归属为四重吸附态的推测没有获得理论结果的支持.     

氧原子在Mo低指数表面及(211)高指数面上的吸附和振动

应用原子和表面簇合物相互作用的5参数Morse势方法(5-MP)对O-Mo低指数表面体系及(211)高指数面体系进行了系统的研究,并获得了全部临界点特性,如吸附位、吸附几何、结合能、正则振动频率等,计算结果表明：在Mo(100)面,O原子吸附在四重洞位,随着覆盖度增加,(100)面发生缺行重构,膺式三重位为稳定吸附位;在Mo(110),(111)及(211)面,O原子均趋向于吸附在膺式三重位．     

氧原子和羟基在Ni低指数表面的吸附动力学研究

应用5-参数Morse势方法模拟了O－Ni表面相互作用势,考察了氧原子在镍三个低指数表面的吸附特性.同时构造了羟基与Ni（100）、Ni（110）和Ni（111）表面相互作用的推广LEPS势,获得了羟基在表面的吸附位、吸附几何、结合能及本征振动等数据.理论结果表明,羟基垂直吸附于镍表面的高对称位是稳定的,垂直吸附于Ni（100）表面4-重洞位的吸附能为96.98 kJ•mol－1,垂直吸附于Ni（111）表面3-重洞位的吸附能为96.00 kJ•mol－1,在Ni（110）表面存在两种吸附态：垂直吸附于长桥位的吸附能为99.38 kJ•mol－1,倾斜14°吸附于赝势三重位吸附能为96.98 kJ•mol－1.理论结果与实验结果符合得较好.     

Adsorption of CO and O2 on W2C(0001)

CO, O(2), and H(2) adsorption on a clean W(2)C(0001)√13×√13 R ± 13.9° reconstructed surface at room temperature (RT) were investigated using high-resolution electron energy loss spectroscopy (HREELS). The W(2)C(0001) adsorbs CO molecularly and adsorbs O(2) dissociatively, but does not adsorb H(2) at RT. In the CO adsorption system, two C-O stretching (antisymmetric CCO stretching) modes were found at 242.3 meV (1954 cm(-1)) and at 253.0 meV (2041 cm(-1)). The low-frequency site is occupied at first with subsequent conversion to the high-frequency site with increasing coverage. Additionally, a small peak was apparent at 104.5 meV (843 cm(-1)), and a middle peak at 50-51 meV (400-410 cm(-1)), which are assignable to a symmetric stretching mode and a hindered translational mode, respectively, of a CCO (ketenylidene) species. These observations are consistent with the CO adsorption model on top of the surface carbon. For oxygen adsorption, two adsorption states were found at 65.2-68.1 meV (526-549 cm(-1)) and 73.6 meV (594 cm(-1)): typical frequencies to oxygen adsorption on metal surfaces. Results suggest that atomic oxygen adsorption occurred on a threefold hollow site of the second W layer.     

Adsorption and Vibration of O Atoms on Fe Low-index and Fe （211） High-index Surfaces

IntroductionThe interaction of oxygen with iron in lowcoverageregimes is considered to be an important step in the for-mation of oxides in corrosion science and in Fisher-Tro-psch process for the synthesis of ammonia over the het-erogeneous catalysts[1]. …     

氢原子在Fe低指数面及高指数面(211)上的吸附和振动

摘要应用原子和表面簇合物相互作用的5参数Morse势方法(5-MP)对H-Fe低指数表面体系及高指数表面体系进行了系统研究, 并获得了吸附位、 吸附几何、 结合能和正则振动频率等全部临界点特性. 理论计算结果表明, 在Fe(100)面, H原子吸附在四重洞位, H-Fe的垂直振动频率为1 009 cm^-1; 在Fe(110)和Fe(211)表面, 趋向于吸附在赝式三重位, H-Fe的垂直振动频率分别为1 054和1 046 cm^-1; 而在Fe(111)表面最稳定的吸附位是近桥位, 频率为1 030 cm^-1.     

氯原子在Ag低指数面上的吸附位和吸附态

应用原子和表面簇合物相互作用的5参数Morse势方法(简称5-MP)对Cl-Ag低指数表面体系进行了研究, 并获得了全部的临界点特性, 如吸附位、吸附几何、结合能、正则振动等. 计算结果表明: 在Ag(100)面上, Cl原子吸附在四重洞位; 在Ag(111)面上, Cl吸附在三重洞位; 尽管第一与第二周期原子在(110)面上的稳定吸附态大都为赝式三重位和长桥位, 但在Ag(110)面上, 四重洞位是氯原子的稳定吸附态. 理论分析结果和实验推测结果符合得很好. 理论结果给出Cl原子在Ag表面的吸附结合能和表面簇合物的粗糙度有关, 结合能从小到大的顺序为(111)＜(100)＜(110).