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1.
1 INTRODUCTION Recently, the researches on inorganic-organic hy-brid compounds represent an advanced field in mate-rial science[1]. At the molecular level, the combina-tion of two extremely different components providesan avenue to design new hybrid materials as well asthe ability to modulate properties of one or more ofthe components[2~6]. Some attractive properties, suchas efficient luminescence[2~4], ideal thermal and me-chanical stability, interesting magnetic[5], non-linearoptical[…  相似文献   

2.
The title compounds have been respectively synthesized by solution process and solvothermal reaction, and their crystal structures were determined by X-ray diffraction method. For (CH3CH2CH2CH2NH3)6(BiI6)(I)2I3 1, it crystallizes in tficlinic, space group P1^- with Mr = 2049.76, a = 8.5719(1), b = 11.7461(3), c = 15.700(1)A, V = 1451.4(1)A^3, Z = 1, Dc = 2.345 g/cm^3, F(000) = 924, μ(MoKα) = 8.907 mm^-1, T = 293(2) K, the final R = 0.0655 and wR = 0.0804 for 2399 observed reflections with I 〉 2σ(I). For (NH3CH2CH2NH3)2Bi2I10 2, it crystallizes in monoclinic, space group P21/n with Mr= 1811.20, a = 8.434(4), b = 13.862(6), c = 13.362(6)A, V = 1499.9(12)A^3, Z = 2, Dc = 4.010 g/cm^3, F(000) = 1536,μ(MoKα) = 22.007 mm^-1, T = 293(2) K, the final R = 0.0584 and wR = 0.1451 for 1798 observed reflections with I 〉 2σ(I). The structures of 1 and 2 contain halobismuthate monomer and dimers, respectively. It is noteworthy that the dimers and their organic counters in 2 connect each other by N…I hydrogen bonds to form a layered structure, and the electrostatic interactions and crystal packing forces between layers give rise to the packing of the crystal. The optical absorption spectra of 1 and 2 reveal the appearance of sharp optical gaps of 2.13 and 2.01 eV, respectively.  相似文献   

3.
[ZnN(CH2CH2NH2)2(CH2CH2N=CHC6H4O)]·Pic的合成与晶体结构   总被引:1,自引:0,他引:1  
在不加任何碱的条件下,三[2-(亚水杨基胺)乙基]胺与苦味酸锌[Zn(Pic)26H2O]在乙醇中反应,得到了较为少见的多胺单缩合西夫碱配体的配合物[ZnN(CH2CH2NH2)2(CH2CH2N=CH-C6H4O)]Pic。化学式为C19H23N7O8Zn,Mr=542.81,晶体属三斜晶系,空间群为P,晶胞参数为a=0.7494(3),b=1.1917(5),c=1.3142(6)nm,a=78.111(7),b=79.093(7),g=78.577(7),V=1.1121(8)nm3,Dc=1.621g/cm3,m(MoKa)=1.167mm-1,Z=2,F(000)=560,在1.602s(I)的可观测点为2433个,最终偏离因子R=0.0555,wR=0.1139。配合物中Zn(II)与配体的4个N原子和1个O原子配位形成变形的三角双锥结构,桥头N和O为锥顶,4个配位N中桥头N与金属离子的配位作用最弱。晶体通过p-p堆积和分子内、分子间的氢键作用形成二维层状超分子结构。  相似文献   

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Using ESR and IR spectroscopy, the structures of >Si(O–C·=O)(CH2–CH3) (1) and >Si(CH2–CH·–CH3)(CH2–CH3) (2) radicals were deciphered. The directions and kinetic parameters of reactions of intramolecular rearrangements in these radicals were determined. The reactions of hydrogen atom abstraction in radical (1) from the CH2 and CH3 groups were studied. It was found that the endothermic reaction of hydrogen atom abstraction from the methyl group occurs at a higher rate than the exothermic reaction with the methylene group. The differences are determined by changes in the size of a cyclic transition state. Based on the experimental data, the strengths of separate C–H bonds in surface fragments are compared. The rearrangement >Si(CH2–CH·–CH3)(CH2–CH3) >Si(C·(CH3)2)(CH2–CH3) was discovered and its mechanism was determined. One of its steps is the skeletal isomerization Si- (2)- . (1)Si- (1)- . (2). Experimental data are analyzed using the results of quantum-chemical calculations of model systems.  相似文献   

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The rate coefficients for the capture process CH + H(2)→ CH(3) and the reactions CH + H(2)→ CH(2) + H (abstraction), CH + H(2) (exchange) have been calculated in the 200-800 K temperature range, using the quasiclassical trajectory (QCT) method and the most recent global potential energy surface. The reactions, which are of interest in combustion and in astrochemistry, proceed via the formation of long-lived CH(3) collision complexes, and the three H atoms become equivalent. QCT rate coefficients for capture are in quite good agreement with experiments. However, an important zero point energy (ZPE) leakage problem occurs in the QCT calculations for the abstraction, exchange and inelastic exit channels. To account for this issue, a pragmatic but accurate approach has been applied, leading to a good agreement with experimental abstraction rate coefficients. Exchange rate coefficients have also been calculated using this approach. Finally, calculations employing QCT capture/phase space theory (PST) models have been carried out, leading to similar values for the abstraction rate coefficients as the QCT and previous quantum mechanical capture/PST methods. This suggests that QCT capture/PST models are a good alternative to the QCT method for this and similar systems.  相似文献   

9.
林进  张萍  王昭煜  王宏根 《结构化学》1999,18(3):188-191
用X-射线晶体结构衍射法测定了[C5H4C(CH3)2CH2CH=CH2]Sm(OH)Cl·2MgCl2·4THF的晶体结构。它属三斜晶系,空间群为P^-1,a=10.773(2),b=12.836(3),c=15.478(3)A,a=111.46(3),β=107.71(3),γ=92.54(3)°,V=1868(1)A^3,Mr=827.91,Dx=1.472g/cm^3,μ=2.0006mm  相似文献   

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CH2与 O2的反应是不饱和碳氢化合物燃烧过程中的一个十分重要的反应 .CH2(基态,三重态)与 O2反应的实验研究工作已有不少报导 [1- 5],其主要产物有两 组 :H2O+ CO和 CO2+ H2,这些产物表明反应在反应体系的单重态位能面上发生 .至今还未见到关于 CH2+ O2反应机理的完整的理论研究报导 .本文用 CASSCF方法详细研究了 CH2+ O2反应的机理,给出从反应物至两组不同最终产物的完整的反应途经的描写 .1计算方法   计算使用量子化学高斯 98 W软件 .用从头算 CASSCF(8,8)/6-31G(d,p)方法在 CH2+ O2单重态位能面上以优化…  相似文献   

12.
CH2+O2反应的反应机理   总被引:3,自引:0,他引:3  
The mechanisms of the CH2+ O2→ H2O+ CO and CH2+ O2→ H2+ CO2 reactions have been studied by performing ab initio CAS(8,8)/6-31G(d,p) calculations, and five intermediates(IMn) and eight transitions(TSn) have been located along the reaction paths. The predicted path for the CH2+ O2→ H2O+ CO is: CH2+ O2→ TS1→ IM1→ TS2→ IM2→ TS3→ IM3→ TS4→ IM4a→ TS5→ H2O+ CO. For the CH2+ O2→ H2+ CO2 reaction, there are two paths: (i) CH2+ O2→ TS1→ IM1→ TS2→ IM2→ TS3→ IM3→ TS6→ H2+ CO2 and (ii) CH2+ O2→ TS1→ IM1→ TS2→ IM2→ TS3→ IM3→ TS4→ IM4a→ TS7→ IM4b→ TS8→ H2+ CO2, with the latter path more favorable energetically.  相似文献   

13.
合成了一种新的双膦-钌-二胺配合物——Rucl2(bdpx)(N心CH2CH2NH2)[bdpx=邻-二(二苯基膦)二甲苯](1),并研究了1催化苯乙酮(2)的加氢反应。在10.032mmol,n(2):n(Me3COK):n(1)=10000:120:1,氢气压力为3MPa的条件下,于70℃反应4h,2的转化率达100%。  相似文献   

14.
滕启文  尚振锋  吴师 《化学学报》1997,55(4):345-350
用INDO方法研究C60与2-甲基烯丙基氯化镁的加成产物HC60[CH2C(CH3)=CH2]的两种异构体的结构和UV谱, 表明1,2-加成产物具有Cs对称性, 1,4-加成产物具有C1对称性, 且前者比后者总能量低, 因而更易于形成。产物中2-甲基烯丙基与C60之间靠极性共价键连接, 并发生前者向后者的电子转移。以此优化构型为基础, 计算两种产物异构体的UV谱, 与实验值一致。同时对电子跃迁进行理论指认, 讨论了产物UV谱带红移的原因。  相似文献   

15.
Photoionization mass spectrometry was used to investigate the dynamics of ion-neutral complex-mediated dissociations of the n-pentane ion (1). Reinterpretation of previous data demonstrates that a fraction of ions 1 isomerizes to the 2-methylbutane ion (2) through the complex CH3CH+CH 3 · CH2CH3 (3), but not through CH3CH+CH2CH 3 · CH3 (4). The appearance energy for C3Hin 7 + formation from 1 is 66 kJ mol?1 below that expected for the formation of n-C3H 7 + and just above that expected for formation of i-C3H 7 + . This demonstrates that the H shift that isomerizes C3H 7 + is synchronized with bond cleavage at the threshold for dissociation to that product. It is suggested that ions that contain n-alkyl chains generally dissociate directly to more stable rearranged carbenium ions. Ethane elimination from 3 is estimated to be about seven times more frequent than is C-C bond formation between the partners in that complex to form 2, which demonstrates a substantial preference in 3 for H abstraction over C-C bond formation. In 1 → CH3CH+CH2CH3 + CH3 by direct cleavage of the C1–C2 bond, the fragments part rapidly enough to prevent any reaction between them. However, 1 → 2 → 4 → C4H 8 + + CH4 occurs in this same energy range. Thus some of the potential energy made available by the isomerization of n-C4H9 in 1 is specifically channeled into the coordinate for dissociation. In contrast, analogous formation of 3 by 1 → 3 is predominantly followed by reaction between the electrostatically bound partners.  相似文献   

16.
《Polyhedron》1999,18(26):3545-3552
Selected ‘3+1’ mixed ligand oxorhenium and oxotechnetium complexes containing the SNS/S donor atom set have been modified by introduction of a bifunctional amine anchor on the p-position of the thiophenolato monodentate ligand. A representative series of complexes containing several tridentate ligands was prepared both at macromolar (Re complexes) and nanomolar (99mTc complexes) amounts. Coupling of these complexes to activated carboxylate groups was performed according to the ‘preformed chelate approach’ using benzoyl chloride as a model molecule. Coupling yields were high both at nanomolar and millimolar metal concentration, as revealed by high-performance liquid chromatographic analysis of 99mTc and Re species adopting parallel radiometric and photometric detection modes. All Re compounds have been characterized by classical analytical methods. In addition, the structures of representative parent ReO[CH3SCH2CH2N(CH2CH2S)2][p-SC6H4NH2] and daughter ReO[CH3SCH2CH2N(CH2CH2S)2][p-SC6H4NHCOC6H5] complexes were solved by X-ray crystallography. Both compounds adopt a distorted trigonal bipyramidal geometry around rhenium, wherein the oxo group and the sulfur atoms of the SNS ligand occupy the equatorial plane and the nitrogen atom and the sulfur of the monothiol are located at the apical positions trans to each other.  相似文献   

17.
CH3S←→CH2SH异化反应的理论研究   总被引:1,自引:0,他引:1  
利用密度泛函理论(DFT)和从头算(ab initio)研究了CH3SCH2SH互异化的反应机理.采用HF、 B3LYP、 MP2理论水平和中等基组6-31(d),计算了CH3S、 CH2SH及其过渡态的结构参数、谐振频率、零点能(ZPE)、总能量和相对能量,并利用B3LYP/6-31(d)的方法计算了反应的内禀反应坐标(IRC),给出了分子构型和自旋污染沿反应坐标的变化曲线,以及最小能量曲线(MEP)、绝热能量曲线.此外,利用传统过渡态理论(CTST)研究了该互异化反应的速率常数和平衡常数在200~1000 K的变化.  相似文献   

18.
采用CCSD(T)/cc-pVDZ//B3LYP/6-311++G(d,p)双水平计算方法研究了CH3CH2O+HCHO反应的微观反应机理. 结果表明, 标题反应主要存在5个抽氢和3个氢迁移异构化反应通道, 其中抽氢通道R→ IMa(CH3CH2O…CH2O)→TS1→ IM1b→P1(CH3CH2OH+CHO)为优势通道, 其表观活化能为14.65 kJ/mol. 利用变分过渡态理论(CVT)并结合小曲率隧道效应模型计算了主通道R1在275~1000 K温度范围内的速率常数kTST, kCVTkCVT/SCT, 在此温度区间内表观反应速率常数三参数表达式为kCVT/SCT=2.26×10-17 T0.57 exp(-1004/T), 显示具有正温度系数效应.  相似文献   

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在密度泛函理论B3LYP/6-311++G(d,p)及MP2/6-311++G(d,p)水平上研究了单电子锂键复合物Y…Li—CH3[Y=CH3, CH2CH3, CH(CH3)2, C(CH3)3]的结构与性质. 结果表明, 三种单电子锂键复合物H3CH2C…Li—CH3(II), (H3C)2HC…Li—CH3(III)和(H3C)3C…Li—CH3(IV)单电子锂键强度依II(-26.7 kJ·mol-1)相似文献   

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