共查询到19条相似文献,搜索用时 609 毫秒
1.
用INDO系列方法对由(C 59N) 2和CH 2Ph 2合成的第一个C 59N衍生物C 59(CHPh 2)N进行了理论研究,得到了C 59(CHPh 2)N的稳定分子构型,表明C 59(CHPh 2)N为Cs对称性,并在此基础上讨论了C 59(CHPh 2)N的UV-Vis光谱、NMR谱.计算表明C 59(CHPh 2)N的二阶非线性光学系数β μ较大. 相似文献
2.
用INDO/2和INDO/SCI方法计算了C 60(C≡N) 2和C 60C(C≡N) 2基态电子结构和电子光谱,所得结果与实验值基本一致.在此基础上,用ZINDO-SOS方法计算了两个分子的二阶非线性光学系数β ijk和β μ,并对其结果进行了分析和讨论.结果表明,乙氰基与C 60相连的两种碳笼衍生物都有大的非线性光学系数,C 60C(C≡N) 2是有希望的非线性光学材料. 相似文献
3.
炼厂干气中回收乙烯是扩宽C 2H 4来源的有效途径,但C 2H 4和C 2H 6物理性质和分子尺寸非常接近,分离困难.金属有机骨架材料(MOFs)近年来在低碳烃分离领域展现出广阔的前景.本工作采用氨吸附改性调节UTSA-280的结构,通过一维直孔道大小的调节实现C 2H 4/C 2H 6的高效分离.改性后的UTSA-280具有独特的超微孔结构能提升C 2H 4的吸附,而完全不吸附稍大的C 2H 6,实现理想的C 2H 4/C 2H 6吸附选择性(>1000).结果表明,改性后的UTSA-280的C 2H 4吸附量可提高至2.83 mmol/g,与未改性的材料相比增加29%,并且能阻挡C<... 相似文献
4.
应用密度泛函B 3LYP方法和从头算(abinitio)HF方法,在3-21G理论水平上,对具有C 2v,D 2d,D 3h和D 6h对称性的四种C 36异构体以及在保持D 2d,D 3h和D 6h对称性条件下形成的不同氢化物进行了量子化学计算,研究了它们在不同量子态时的分子几何构型和电子结构.结果表明,电子相关效应在C 36簇化合物的电子结构中起着重要作用.它们最稳定的结构是C 36的 3A 2u量子态D 6h异构体,而C 36的氢化物是在D 3h异构体的C 2位置等同碳原子上形成的 1A 1'量子态氢化物C 36H 12. 相似文献
5.
用INDO系列方法对C 60的取代产物C 59O进行几何构型优化,得到Cs对称性的稳定构型,以此构型为基础,计算并预测了C 59O的电子光谱和NMR谱.最后与C 59O的等电子分子体C 602-及C 60O进行了比较. 相似文献
6.
在ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β的程序.研究了(二噻吩[3,2-b:3',2'-d]环戊烷-4-亚基)C 60中的分子轨道相互作用,计算了该分子的电子光谱和二阶非线性光学系数卢,前者与实验结果吻合较好,后者属于理论预测性质. 相似文献
7.
用B 3LYP/6-311G(d,p)密度泛函方法对B 2H 5+阳离子和B 2H 5·自由基的几何异构体的空间构型进行了优化,并在此基础上用QCISD(T)/6-311++G(3df,2p)偶合簇法进行了单点能计算和零点能校正.结果表明,B 2H 5+单态有2种稳定的几何构型(D 3h,C 1),其中C 1构型是新发现的.B 2H 5+三重态阳离子除已知C s构型外,又发现两种稳定构型(C 1).对于B 2H 5·自由基体系,共有4种异构体(包括两种新发现的构型C s),其中,具有单桥结构的C 2v最稳定.用二级多体微扰理论和密度泛函方法对前人所认为稳定的B 2H 5+单态的C 2v构型进行了全优化,结果发现该构型始终具有一个虚频,不是稳定构型.对B 2H 5-阴离子体系的单态和三重态进行的全优化,理论上得出单态时具有C 2v和C s两种稳定构型,而三重态只有C 2v一种稳定构型. 相似文献
8.
用INDO系列方法对双笼化合物C 120CO进行了理论研究,结果表明,C 120CO中O具有较大的电负性,在此位置可形成氢键.分子内电荷转移较大,非线性光学系数可能较大.C 120CO的电子光谱与C 120CH 2和C 120O的相似. 相似文献
9.
用INDO系列方法对C 60O 3的可能构型进行研究,结果表明:环氧结构邻近的6-6键易发生进一步的加成反应.其中3个氧原子加在同一个六元环的6-6边上,形成环氧结构最稳定的C 3v构型,第3个氧原子加在2个环氧结构相邻的六元环的6-6边上的C 2、C s构型也相当稳定,C 2、C s构型的部分 13C NMR谱与实验吻合.C 60O 3可能有较好的反应活性,其电子光谱属于理论预测. 相似文献
10.
采用密度泛函理论(DFT)计算了MgAl-LDHs层板与无机阴离子(F -、Cl -、NO 3-、CO 32-、SO 42-)和有机阴离子(水杨酸根离子([HO(C 6H 4)COO] -)、苯甲酸根离子([(C 6H 5)COO] -)、对二甲氨基苯甲酸根离子([p-(CH 3) 2N(C 6H 4)COO] -)、十二烷基磺酸根离子[C 12H 25SO 3] -、己烷基磺酸根离子[C 6H 13SO 3] -、丙烷基磺酸根离子[C 3H 7SO 3] -)间的相互作用,获得稳定超分子几何结构及相互作用能。层板主体与客体间存在较强的超分子作用,包括主客体间静电作用和氢键等。主、客体间相互作用能数值大小顺序为CO 32- > SO 42- > F -> Cl -> NO 3-;[p-(CH 3) 2N(C 6H 4)COO] -> [(C 6H 5)COO] -> [HO(C 6H 4)COO] -和[C 12H 25SO 3] -> [C 6H 13SO 3] - > [C 3H 7SO 3] -。另外,还采用自然键轨道(NBO)计算和分析了LDHs 层板与阴离子间作用机理,从二阶微扰理论计算得到的稳定化能变化趋势与相互作用能数据基本吻合。 相似文献
11.
Ab initio study of the reactions of n-heptyl radicals(1-C 7H 15, 2-C 7H 15, 3-C 7H 15, and 4-C 7H 15) with methanol was conducted over the temperature range of 300-1500 K. Transition states for the reaction channels producing C 7H 15OH, CH 3, C 7H 15OCH 3, H, C 7H 16, CH 2OH and CH 3O were identified and the geometries of all stationary points were calculated at BB1K/MG3S level of theory. The potential barrier heights of the corresponding transition states were predicted by the CBS-QB3//BB1K and G4//BB1K methods, indicating that the eight H-abstraction channels are more kinetically favorable than the channels where OH transfers from CH 3OH to C 7H 15 and where the C 7H 15OCH 3+H products are given. The rate constants of H-abstraction channels were calculated with TST and TST/Eck. Both the forward and reverse rate constants have positive temperature dependence and the tunneling effect is only important at the temperature lower than 700 K. For the reactions of H-atom abstraction from methyl in CH 3OH by n-heptyl, a reverse and the corresponding forward rate constant are roughly equal. For the reactions of H-atom abstraction from OH in CH 3OH by n-heptyl, a reverse rate constant is larger by several orders of magnitude than the corresponding forward one. 相似文献
12.
Reaction of R---N=C=N---R (R= p-Me-C 6H 4) and R---P==C=P---R (R=2,4,6- tBu 3C 6H 2) with the di-iron aminocarbene complex [Fe 2(CO) 7{1μ-C(Ph)C(NEt 2)}] (1c) gave corresponding complexes [Fe 2(CO) 6{C(Ph)C(NEt 2)C(NC 6H 4Me)N (C 6H 4Me)}] (2) and [Fe 2(CO) 6{C(Ph)C(NEt 2)C(PC 6H 2tBu 3)P(C 6H 2tBu 3)}] (4), resulting from a coupling reaction with carbon-carbon bond formation. [Fe 2(CO) 5(CNC 6H 4Me){C(Ph)C(NEt 2)N(C 6H 4Me)}], complex 3, obtained in the reaction with R---N=C=N---R, resulted from C=N bond rupture insertion of a nitrene fragment into the Fe=C bond. Complexes 2–4 were characterized by X-ray diffraction. The different geornetries of complexes 2 and 4 are discussed. The formation of these complexes may be explained by cycloaddition on the Fe =C metal-carbene bond. 相似文献
13.
The preparation and properties as well as some reactions of a series of arylcarbonylbis(triphenylphosphine)iridium(I) complexes [Ir(Ar)(CO)(PPh 3) 2] (Ar = C 6H 5, C 6F 5, 2-C 6H 4CH 3, 3-C 6H 4CH 3, 4-C 6H 4CH 3, 2-C 6H 4OCH 3, 2,6-C 6H 3-(OCH 3) 2, 4-C 6H 4N(CH 3) 2, 3-C 6H 4Cl, 4-C 6H 4Cl, 4-C 6H 4Cl, 3-C 6H 4CF 3, 4-C 6H 4CF 3) are described, and the most important IR data as well as the 31P NMR parameters of these, without exception trans-planar, compounds are given. Some of the complexes react with molecular oxygen to form well defined dioxygen adducts [Ir(Ar)(O2)(CO)(PPh3)2] (Ar = C6H5, 3-C6H4CH3, 4-C6H4CH3). Complexes with ortho-substituted aryl ligands are not oxygenated. This effect is referred to as a steric shielding of the metal center by the corresponding ortho-substituents. With SO2 the similar irreversible addition compound [Ir(4-C6H4CH3)-(SO2)(CO)(PPh3)2] is obtained. Sulfur dioxide insertion into the Ir---C bond cannot be observed. The first step of the reaction between [Ir(4-C6H4CH3)(CO)(PPh3)2] and hydrogen chloride involves an oxidative addition of HCl to give [Ir(H)(Cl)(4-C6-H4CH3)(CO)(PPh3)2]. Ir---C bond cleavage by reductive elimination of toluene from the primary adduct does not occur except at elevated temperature. 相似文献
14.
The coordinatively unsaturated uranium(IV) complex U[N(C 6H 5) 2] 4 has been prepared via the stoichiometric reaction of diphenylamine with [(Me 3Si) 2N] 2
H 2. U[N(C 6H 5) 2] 4 coordinates Lewis bases such as Et 2O, THF, pyridine or (EtO) 3PO, based on electronic absorption spectroscopy and 1H NMR studies. Exchange between U[N(C 6H 5) 2] 4 and U[N(C 6H 5) 2] 4(L), where L is THF or pyridine, is rapid on the NMR time-scale between 307 and 323 K. Measurement of equilibrium constants for L = THF provides Δ H and Δ S values of −60 kJ mol −1 and −1.8 × 10 2 J K −1 mol −1, respectively. U[N(C 6H 5) 2] 4 coordinates and binds (EtO) 3PO much more tightly ( Keq = & > 10 4 M −1) than THF or pyridine with the exchange rate between U[N(C 6H 5) 2] 4 and U[N(C 6H 5) 2] 4[OP(OEt) 3] being close to the NMR time-scale. 相似文献
15.
The study of the reactivity of R---CH=N---(C 6H 4-2-SMe) with R=C 6H 5 or 2,4,6-Me 3-C 6H 2 with palladium(II) salts is reported. These studies have allowed us to prepare and characterize the coordination complexes: cis-[Pd{R---CH=N---(C 6H 4-2-SMe)}Cl 2] {R=C 6H 5 or 2,4,6-Me 3-C 6H 2} and the cyclopalladated compounds [Pd{C 6H 4---CH=N---(C 6H 4-2-SMe)}Cl] and [Pd{(2-CH 2-4,6-Me 2-C 6H 2)---CH=N---(C 6H 4-2-SMe)}Cl]. The X-ray crystal structures of the latter complexes reveal that the thioimines act as a [Csp 2, phenyl,N,S] − and as a [Csp 3, N,S] − terdentate group, respectively. The study of the reactions of the cyclopalladated compounds with PPh 3 is also reported. 相似文献
16.
C6 0 具有 30个等同的可参与化学反应的活泼双键 ,制备并表征富勒烯多加成产物是富勒烯化学中最前沿的课题之一 .Hirsch等[15 ]通过研究C6 0 亚甲基加成反应 ,提出了双加成物立体选择性的一般规律 .我们在C6 0 氧加成方面做了类似的研究工作[6 8].本文选取几类富勒烯环双加成衍生物即富勒烯氧化产物C6 0 O2 [6 ]( 1 )、富勒烯含氮衍生物C6 0 (NH) 2 [5 ]( 2 )、富勒烯含吡咯环衍生物C6 0 (CH2 NHCH2 ) 2 [9]( 3)和富勒醇前体C6 0 (SO4) 2 [10 ]( 4)作为模型分子进行理论研究 ,以探寻富勒烯多加成反应的一般性规律 .… 相似文献
17.
Liquid crystalline 4-XC 6H 4N=NC 6H 4X-4′ [X = C 4H 9 (1a), C 1OH 21 (1b), OC 4H 9 (1c), OC 8H 17(1d)] can be easily prepared in high yields from the corresponding anilines. In order to study the influence of metals on the thermal properties of these materials, we have obtained adducts [AuCl 3(4-C 4H 9OC 6H 4N=NC 6H 4OC 4H 9-4′)] (2) and [Ag(OC1O 3)L 2] [L = 4-XC 6H 4N=NC 6H 4X-4′; X = OC 4H, (3a), OC 8H 17 (3b)]. The silver adducts show themotropic behaviour. Mercuriation of dialkylazobenzenes 1a-b takes place with [Hg(OAc) 2] and LiCl to give [Hg(R)Cl] [R = C 6H 3(N=NC 6H 4X-4′)-2, X-5; X = C 4H 9 (bpap) (4a), C 10H 21 (dpap) (4b)] while dialkoxyazobenzenes 1c–d require [Hg (OOCCF 3) 2] to obtain [Hg(R)Cl] [R = C 6H 3(N---NC 6H 4X-4′)-2, X-5; X = OC 4H 9 (bxpap) (4c), OC 8H 17 (4d)]. 4a-c react with NaI to give [HgR 2] [R= bpap (5a), dpap (5b), bxpap (5c), oxpap (5d)l. Both chloroaryl-, 4a and 4c, and diaryl-mercurials, 5a and 5c, act readily as transmetailating agents towards [Me 4N] [AuCl 4] in the presence of [Me 4N]Cl to give [Au(η 2-R)Cl 2] [R = bpap (6a), bxpap (6b)]. After reaction of [AuCl 3(tht)] (tht = tetrahydrothiophene) with [Me 4N]Cl and 4b (1:2:1), [Me 4N][Au(dpap)Cl 3] (7) can be isolated. C---H activati bxpap (8b)]. None of the complexes 4–8 shows mesomorphic behaviour. 相似文献
18.
The complex triplet potential energy surface of the C 2H 3N system is investigated at the UB3LYP and CCSD(T) (single-point) levels in order to explore the possible reaction mechanism of C 2H 3 radical with N( 4S). Eleven minimum isomers and 18 transition states are located. Possible energetically allowed reaction pathways leading to various low-lying dissociation products are obtained. Starting from the energy-rich reactant C 2H 3+N( 4S), the first step is the attack of the N atom on the C atom having one H atom attached in C 2H 3 radical and form the intermediate C 2H 3N(1). The associated intermediate 1 can lead to product P 1 CH 2CN+H and P 2 3CH 2+ 3HCN by the cleavage of C–H bond and C–C bond, respectively. The most favorable pathway for the C 2H 3+N( 4S) reaction is the channel leading to P 1, which is preferred to that of P 2 due to the comparative lower energy barrier. The formation of P 3 3C 2H 2+ 3NH through hydrogen-abstraction mechanism is also feasible, especially at high temperature. The other pathways are less competitive comparatively. 相似文献
19.
The carbonyl derivatized bis(alkyne) O=C(4-C 6H 4OCH 2CCH) 2 was converted into the imine derivatives RN=C(4-C 6H 4OCH 2CCH) 2 [R=OH, NHC(O)NH 2, NHC 6H 3-2,4-(NO 2) 2] and into the 4-bromomethyl-1,3-dioxolane derivative BrCH 2C 2H 3O 2C(4-C 6H 4OCH 2CCH) 2. The alkyne units in these compounds react with [AuCl(SMe 2)] in the presence of base to form the corresponding digold(I) diacetylide complexes, that exist as insoluble oligomers or polymers. They reacted with the diphosphines Ph 2PZPPh 2 [Z=CC, trans-HC=CH and (CH 2) n, n=3–5] to give macrocyclic gold(I) complexes of the type [Au 2(μ-LL)(μ-PP)], where LL is the diacetylide and PP the diphosphine ligand. The ability of these macrocyclic complexes to self-assemble to [2]catenanes has been studied. The ketone and imine derivatives do not form [2]catenanes because the orientation of the aryl groups is unfavorable, but the 1,3-dioxolane derivatives may catenate if the ring size is optimum. 相似文献
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