乙烯基自由基(C2H·3)与羟基自由基(OH·)反应势能面的理论研究

在QCISD（T）/6-311G（2df,p)//B3LYP/6-311G（d,p)水平上对自由基反应C2H3^. OH^.进行了计算，结果表明，经过缔合、多步H转移、CH3转移和离解等复杂过程，最终要得到8种产物（P1-P8），茯中产物P2（H2CCO H2）和P6（CH3CO^. H^.）是主要产物。本文得到的CH2CHOH（1或1‘），CH3CHO（2）和CH3COH（3）之间的过渡态TS1/2，TS1‘/3和TS2/3的能量顺序与Wesdemiotis等的实验推测相反，而与Smith等的计算结果一致。     

利用氧化加成反应合成[Cu(C_6H_5COO)_2(C_5H_5N)_2(H_2O)]

室温下 ,金属铜粉和过氧化苯甲酰进行氧化加成反应合成了铜化合物 [Cu(C6H5COO) 2 (C5H5N) 2 (H2 O) ](1 )。通过元素分析、电导、红外光谱等方法对配合物进行了表征 ,并经X 射线单晶结构分析确定了配合物的结构 ,晶体属单斜晶系 ,空间群Cc ,a =0 .60 78(4) ,b =1 .5879(4) ,c =2 .30 91 (3)nm ,β =97.61 (2 )°,Z =4,V =2 .2 0 91nm3,R =0 .0 30 7,中心铜原子由单齿配位的苯甲酸根的氧原子和吡啶的氮原子及来自水分子的氧原子形成四方锥配位结构。     

邻苯二酚衍生物与稀土元素配位反应的研究(V)——3,4-二羟基苯甲酸与铈(Ⅲ)的配位与转型反应

研究了稀土元素铈(Ⅲ)离子与3,4-二羟基苯甲酸(H3L)在水溶液体系中生成羧基配位化合物的条件,表征其组成为Ce(H2L)2(OH)·3H2O,并研究了该配合物在一定条件下,铈离子由羧基配位反应变为由两八邻酚羟基配位的配合物[Ce(HL)n]的转型反应及氧化成铈(Ⅳ)配合物的反应.     

邻苯二酚衍生物与稀土元素配位反应的研究(Ⅴ)——3,4-二羟基苯甲酸与铈(Ⅲ)的配位与转型反应

研究了稀土元素铈(Ⅲ)离子与3,4-二羟基苯甲酸(H₃L)在水溶液体系中生成羧基配位化合物的条件,表征其组成为Ce(H₂L)₂(OH)·3H₂O,并研究了该配合物在一定条件下,铈离子由羧基配位反应变为由两个邻酚羟基配位的配合物[Ce(HL)_n]的转型反应及氧化成铈(Ⅳ)配合物的反应。     

离子交换树脂催化对羟基苯甲酸酯化反应的研究*

本文研究了一种固体酸催化剂一阳离子交换树脂催化剂,用于对羟基苯甲酸的酯化反应。通过对不同树脂进行筛选,发现ＪＫ００８的催化活性比较高。本文还进一步考察了ＪＫ００８催化剂的使用寿命,研究了合成对羟基苯甲酸乙酯的最佳反应条件。     

DFT法研究3-羟基丙烯醛的双键旋转异构反应机理

利用密度泛函理论(DFT)分别在B3LYP/6-31G**和B3LYP/6-311＋＋G**的计算水平上优化了基态3-羟基丙烯醛分子在双键旋转异构反应过程中的平衡态以及过渡态的几何构型，分析了反应过程中键参数的变化，计算了该反应的内禀反应坐标(IRC)，发现在重排反应途径上存在一个四元环骨架的中间体.通过振动分析对平衡态和过渡态进行了确认，并得到了零点能.计算结果表明，基态3-羟基丙烯醛分子的双键旋转异构反应经过两步完成，第一步反应位垒稍高，第二步反应位垒较低，存在着发生重排反应的可能性.     

对位取代苯甲酸酯晶体结构研究——Ⅰ.对羟基苯甲酸甲酯p-(OH)C_6H_4CO_2CH_3的晶体结构

对羟基苯甲酸甲酯(p—MHB)晶体结构已用X射线衍射法测定。晶体属单斜晶系,空间群为Cc,晶胞参数:a=13.568(5),b=16.959(7),c=12.458(6),β=130.10(3)°。ρobs=1.361gcm~(-3),Z=12,ρ=1.382 gcm~(-3)。使用CAD4四圆衍射仪和MoKα射线收集强度数据,晶体结构用直接法解出,经全矩阵最小二乘修正,对于1098个I>3σ(I)的衍射点的最后偏离因子R=0.054。晶胞中12个分子分成各自独立的三套坐标排布,且三套p—MHB分子构型基本相同。对位取代的OH和CO_2CH_3基团与苯环共平面,苯环上的碳-碳键长呈现“醌型”缩短。     

H_2O-DMF混合溶剂中[Co(N_3)(NH_3)_5]~(2 )与[Fe(H_2O)_6]~(2 )间电子转移反应

研究了H_2O-DMF馄合溶剂中[Co(N_3)(NH_3)_5]~(2 )被Fe(Ⅱ)还原的反应速度变化规律后,证实:当DMF的摩尔分数X_(DMF)<0.3时,表观速度常数K_(aDD)随着X_(DMF)增大而增大;X_(DMF)>0.3时,K_(app)随着X_(DMF)增大而减小;K_(aDD)与[H~ ]有良好线性关系。 H_2O-DMF混合溶剂中所测定的吸收光谱显示出:近紫外区溶液的吸光度随X_(DMF)增大而增大,它反映出Fe(Ⅱ)的配位圈中配体H_2O分子被DMF分子逐渐置换而形成混合配体配合物的过程。 还观察到,在H_2O-DMF混合溶剂中,Fe(Ⅱ)的电极电势与X_(DMF)的依存性:随X_(DMF)增加,Fe(Ⅱ)的电极电势下降,但X_(DMF)>0.3后,Fe(Ⅱ)的电极电势几乎为一定值。 因此,反应速度的变化,可归因于Fe(Ⅱ)配位圈中水分子的被置换和Fe(Ⅱ)电极电势的变化上。     

O(3P)+O2H→OH+O2反应机理的密度泛函理论研究

用密度泛函理论方法研究了O(3P)与O2H反应生成羟基和氧分子的反应机理. 在PW91/6-31+G水平上用梯度解析技术全自由度优化上述反应物、产物和反应路径上的中间体及过渡态几何构型, 并通过频率振动分析加以确认, 计算IRC反应路径及中间体异构化过程, 确定了此反应的可能反应通道. 结果表明: 该反应是多通道多步骤的强放热反应. 首先形成顺式或反式O3H富能中间体, 此过程无能垒; 然后跨过一个能垒分解成产物OH和O2. 通道IM1→TS1比IM2→TS2克服的能垒要大, 反应放热372.822 kJ*mol-1. IM1TS3IM2 可相互转化.     

羟基苯甲酸的3种异构体的毛细管区带电泳分离研究

 采用十六烷基三甲基溴化铵 (CTAB)为电渗流改性剂 ,考察了邻羟基苯甲酸、间羟基苯甲酸和对羟基苯甲酸在高效毛细管区带电泳模式下的分离行为 ,研究了缓冲液的pH和添加剂甲醇的用量对这 3种同分异构体的分离、峰形和出峰顺序的影响 ,并据此优化了这 3种异构体的分离条件。     

Synthesis and reactivity of [N(C6H4Br)3][B(C6F5)4]: the X-ray crystal structure of [Fe(C5H5)2][B(C6F5)4]

A new chemical oxidant [N(4-C₆H₄Br)₃][B(C₆F₅)₄], was prepared and used to synthesize [Fe(C₅H₅)₂][B(C₆F₅)₄]. The crystal structure of [Fe(C₅H₅)₂][B(C₆F₅)₄] was determined.     

Facile synthesis of isomerically pure fullerenols C60(OH)5Br and 1,4-C60(OH)2 from chlorofullerene C60Cl6

The chlorofullerene C₆₀Cl₆ was demonstrated as a versatile precursor for the synthesis of two isomerically pure fullerenols via tetrabutylammonium bromide promoted reactions with water. Performing the synthesis in wet chlorobenzene produced 1,4-C₆₀(OH)₂ as the only isolable product along with substantial amounts of non-functionalized C₆₀. However, the addition of DMSO as a co-solvent altered the reaction pathway, leading to the formation of C₆₀(OH)₅Br as the main product. Both isolated compounds were novel and their molecular compositions and structures were confirmed by mass spectrometry and NMR spectroscopy. The fullerenol C₆₀(OH)₅Br, which was formed in a moderate yield, represents the first isomerically pure polyhydroxylated fullerene available on a large scale.     

配合物Zn(C3H4N2)2(C8H6O2Br)2的水热合成、晶体结构及性质

在140℃下,以3-溴-4-甲基苯甲酸和咪唑为配体,通过水热法在甲醇/水混合溶剂中反应24 h合成了锌(Ⅱ)配合物Zn(C3H4N2)2(C8H6O2Br)2。通过元素分析、红外光谱、热重分析和X射线粉末衍射对配合物进行了结构表征,同时用X射线单晶衍射分析确定了其晶体结构。结果表明,其晶体属单斜晶系,空间群为C2/c,晶胞参数:a=13.257(3),b=9.765(2),c=20.494(4),β=107.79(3)°,V=2526.3(9)3,Dc=1.655g·cm-3,μ=4.170mm-1,F(000)=1248,Z=4,最终残差因子R1=0.0552,wR2=0.1378。配合物为单核结构,中心锌(Ⅱ)离子与来自2个3-溴-4-甲基苯甲酸根的2个O原子及2个咪唑分子的2个N原子配位,形成了畸变的四方锥几何体。晶体内,分子间则通过N—H…O氢键作用在ab面形成了层状结构。研究了配合物的发光性质。     

Standard molar enthalpies of formation of Ln(C9H6NO)2(C2H3O2) (Ln: Nd, Sm)

Using an on-line solution-reaction isoperibol calorimeter, the standard molar enthalpies of reaction for the general thermochemical reaction: LnCl₃·6H₂O(s) + 2C₉H₇NO(s) + CH₃COONa(s) = Ln(C₉H₆NO)₂(C₂H₃O₂)(s) + NaCl(s) + 2HCl(g) + 6H₂O(l) (Ln: Nd, Sm), were determined at T=298.15 K, as  kJ mol^−l, respectively. From the mentioned standard molar enthalpies of reaction and other auxiliary thermodynamic quantities, the standard molar enthalpies of formation of Ln(C₉H₆NO)₂(C₂H₃O₂)(s) (Ln: Nd, Sm), at T=298.15 K, have been derived to be: −(1494.7±3.3) and −(1501.5±3.4) kJ mol^−l, respectively.     

Crystal and molecular structures of the Rh[(C2H5O)2PS2]3 and Co[(C6H5O)2PS2]3 chelate compounds

The crystal structures of the Rh[(EtO)₂PS₂]₃ (I) and Co[(PhO)₂PS₂]₃ (II) chelate compounds were determined from X-ray diffraction (XRD) data (CAD-4 diffractometer, MoK _β radiation, 1193 F _hkl , R = 0.0516 for I and 513 F _hkl , R = 0.0305 for II). Crystals I are monoclinic: a = 14.233(3) Å, b = 13.570(3) Å, c = 14.272(3) Å; β = 90.66(3)°, V = 2756.3(10) ų, Z = 4, ρ_calc = 1.587 g/cm³, space group C2/c. Crystals II are trigonal: a = 15.149(2) Å, c = 30.306(6) Å; V = 6023.2(16) ų, Z = 6, ρ_calc = 1.493 g/cm³, space group R3ˉ. Structures I and II consist of discrete mononuclear molecules. The coordination polyhedra of the M atoms (M = Rh, Co) are distorted octahedra formed by six sulfur atoms of three cyclic bidentate (RO)₂ PS₂⁻ ligands. Original Russian Text Copyright ? 2008 by R. F. Klevtsova, L. A. Glinskaya, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 2, pp. 330–334, March–April, 2008.     

A localized molecular orbital study on the bonding of> Mo3S4]2Mo> and> Mo3S4]CuI> versus (C6H6)2Cr and C6H6Cr(CO)3

The energy-localized CNDO/2 molecular orbitais have been calculated for the clusters containing molybdenum, > {Mo₃S₄₂Mo}⁸⁺ and> Mo₃S₄]CuI> ⁴⁺, versus the prototype arene-metal sandwich (C₆H₆)₂Cr and half-sandwich complexes C₆H₆Cr(CO)₃. The bonding characteristics of these compounds are described from a localization bonding viewpoint. There are two typical M-arene and M-[Mo₃S₄] bondings. One is formed by electron donation from the three-center two-electron π-bonds in the arene or [Mo₃S₄]⁴⁺ ligands into the vacant hybrid orbitais of the “stranger” metal atom. In the other M-arene or M-[Mo₃S₄] bond there is very little donation by the lone electron pair occupying the d AOs of the “stranger” metal atom to the arene or [Mo₃S₄]⁴⁺ ligands. The analogy of the ligand [Mo₃S₄]⁴⁺ in the clusters studied with the ligand benzene is also briefly discussed.     

C2H4在Fe3C(100)表面吸附及脱氢裂解的密度泛函理论研究

采用自旋极化密度泛函理论和周期平板模型,对C₂H₄在铁基费托合成催化剂活性相之一Fe₃C（100）表面从热力学和动力学两个方面分析了C₂H₄在Fe₃C（100）表面进行脱氢和裂解反应的竞争性。结果表明,C₂H₄在Fe₃C（100）表面的μ-bridging吸附比π、di-σ吸附更加稳定;C₂H₄与Fe₃C（100）面的相互作用导致C₂H₄的C原子部分发生重新杂化（sp²→sp³）,使C原子呈近四面体结构。在Fe₃C（100）表面C₂H₄易于发生脱氢反应,C-C键裂解反应不具有竞争性。亚乙烯基CCH₂和乙烯基CHCH₂是Fe₃C（100）表面最丰的C₂物种,或是C₂H₄参与链增长的主要单体形式。     

二维网状有机锑对氨基苯乙酸酯的合成、表征及晶体结构研究

The title complex bis(4-aminophenylacetate)triphenylantimony(V) has been synthesized by the reaction of triphenylantimony dibromide with 4-aminophenylacetic acid in 1∶2 molar ratio. The complex was characterized by elemental analysis, IR spectra, NMR ( ¹H, ¹³C) and X-ray diffraction crystal structure analysis. This complex crystallizes in the monoclinic system, space group C2/c with a=2.279 4(2) nm, b=0.957 10(10) nm, c=1.335 49(15) nm, β=93.781(2)°. The molecular structure adopts a distorted trigonal bipyramidal geometry around the antimony atom. In the crystal structure molecules are connected by intermolecular N-H…O hydrogen-bonding interactions forming a two-dimensional network structure. CCDC: 726039.     

Ortho-metallation of a sulphur-donor ligand: preparation structure of C6H4CH2SMeMn(CO)3(PPH3)

ortho-Metallation of PhCH₂SMe in a reaciton with MeMn(CO)₅ ahs been confirmed by a single crystal X-ray structural determination of the title complex.     

乙烷在V2O5(001)表面深度氧化反应机理的周期性密度泛函理论研究

采用周期密度泛函理论研究了V₂O₅ (001)表面乙烷深度氧化过程.结果表明,乙醛是主要的副产物,且脱附态的乙醛能很容易被氧化成乙酸,但多数乙醛在从表面脱附前已被氧化成CO_x.显然,在乙烷氧化脱氢反应的最终产物CO_x主要来源于乙醛.