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1.
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   

2.
3.
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   

4.
The reaction of Sn[CH(SiMe3)2]2 and ethyne at ambient temperature affords a mixture of products, from which the title compound has been separated and identified by IR, 1H, and 13C NMR spectroscopy.  相似文献   

5.
Compounds [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) (I) and Ag3(CF3COO)3(CH3CN)2(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) Å3, Z= 8, R 1= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) Å3, Z= 2, R 1= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.  相似文献   

6.
用密度泛函理论UB3LYP/6-31G(d,p)方法研究了二甲胺自由基(CH3)2N及其质子化离子(CH3)2NH 的构象和超精细结构.在由构象研究得到的两种自由基的最稳定结构上,用密度泛函的UB3LYP和UB3PW91方法及从头计算的UHF、UMP2(FULL)方法计算了α-质子、β-质子和N核上的超精细偶合常数A(Hα)、A(Hβ)和A(N)结果表明:两种自由基中甲基内旋转的位垒均很低,分别为0.46kJ·mol-1((CH3)2NH )和2.6kJ·mol-1((CH3)2N).UB3LYP/6-31G(d,p)和UB3PW91/6-31G(d,p)计算的A(Hα)、A(Hβ)和A(N)与ESR实验结果符合得很好,UMP2/6-31G(d,p)方法的计算值与实验值符合得也较好.  相似文献   

7.
The reaction for CH3CH2+O(3P) was studied by ab initio method. The geometries of the reactants, intermediates, transition states and products were optimized at MP2/6-311+G(d,p) level. The corresponding vibration frequencies were calculated at the same level. The single-point calculations for all the stationary points were carried out at the QCISD(T)/6-311+G(d,p) level using the MP2/6-311+G(d,p) optimized geometries. The results of the theoretical study indicate that the major products are the CH2O+CH3, CH3CHO+H and CH2CH2+OH in the reaction. For the products CH2O+CH3 and CH3CHO+H, the major production channels are A1: (R)→IM1→TS3→(A) and B1: (R)→IM1→TS4→(B), respectively. The majority of the products CH2CH2+OH are formed via the direct abstraction channels C1 and C2: (R)→TS1(TS2)→(C). In addition, the results suggest that the barrier heights to form the CO reaction channels are very high, so the CO is not a major product in the reaction.  相似文献   

8.
杀虫单(CH3)2NHCH(CH2S2O3)2Na·H2O是我国独自开发的一种沙蚕毒系仿生性农药.我们用循环伏安法和计时库仑法研究了杀虫单的电极反应过程及在电位扫描速率,支持电解质PH以及浓度变化时对峰电流及峰电位的影响.研究表明杀虫单发生不可逆还原电极反应,还原产物二氢沙蚕毒素在电极上发生强吸附,其吸附量为8.23×10-10mol/cm2.在随后的循环电位扫描中二氢沙蚕毒素氧化生成沙蚕毒素在循环伏安图上出现新电流峰.沙蚕毒素与二氢沙蚕素的峰电位相差33mV,两者间有2电子可逆电极反应特征  相似文献   

9.
Crystals of [Cr3O(CH3COO)6(H2O)3][UO2(CH3COO)3]·3H2O (I) were synthesized for the first time and studied by X-ray crystallography. The crystals of I are orthorhombic: a = 8.3561(3) ?, b = 16.8421(5) ?, c = 25.7448(9) ?, V = 3623.2(2) ?3, space group P212121, Z = 4, R = 0.0409. The structure is composed of trinuclear [Cr3O(CH3COO)6(H2O)3]+ complexes and mononuclear [UO2(CH3COO)3]? complexes classified with crystal-chemical groups A3M3B 6 2 M 3 1 (A = Cr3+, M3 = O2?, B2 = CH3COO?, M1 = H2O) and AB 3 01 (A = UO 2 2+ , B01 = CH3COO?), respectively. The complexes are bound to each other by electrostatic interactions and hydrogen bonds involving outer-sphere water molecules. The results of IR spectroscopic study of I are in good agreement with the structural data for the crystal.  相似文献   

10.
无机-有机杂化钒氧酸盐由于其结构的多样性以及在催化、医药、光、电、磁等材料领域中的应用前景而受到人们的广泛关注。近年来这一研究领域的重大进步是将有机氮配体或者过渡金属配合物直接连接到矾氧骨架上以获得各种新奇结构。合成出许多属于L/V/O、MXLY/V/O、L/P/V/O和MXLY  相似文献   

11.
The reaction for CH3CH2+N(4S) was studied by ab initio method. The geometries of the reactants, intermediates, transition states and products were optimized at MP2/6-311+G(d,p) level. The corresponding vibration frequencies were calculated at the same level. The single point calculations for all the stationary points were carried out at the QCISD(T)/ 6-311+G(d,p) level using the MP2/6-311+G(d,p) optimized geometries. The results of the theoretical study indicate that the major products are the CH2CH2+3NH and H2CN+CH3, and the minor products are the CH3CHN+H in the reaction. The majority of the products CH2CH2+3NH are formed via a direct hydrogen abstraction channel. The products H2CN+CH3 are produced via an addition/dissociation channel. The products CH3CHN+H are produced via an addition/dissociation channel.  相似文献   

12.
T A dinuclear cadmium complex[Cd2(phen)2(C14H11O3)4(CH3CH2OH)]·(CH3OH)·(H2O)has been synthesized with benzilic acid and 1,10-phenanthroline by hydrothermal method.The crystal structure was determined bv X-ray diffraction with crystal parameters as follows:triclinic system with space group P-1,α=1.21298(10),b=1.32586(1 1),c=2.4815(2)nm,α=76.2630(10),β=81.4500(10),γ=69.1700(10)°V=3.6143(5)nm3,Dc=1.438g/cm3,Z=1,F(000)=1600,the final GOOF=0.937,R=0.0521 and wR=0.1328.In the title complex,the dinuclear structure is defined by carboxyl oxygen atoms adopting a monodentate bridged coordination mode.The coordination environment of Cd(Ⅱ)ion is CdO4N2,giving a distorted octahedral coordination geometry.TG analysis shows that the title complex is stable under 140℃.  相似文献   

13.
The Platinum(II) diamine with N,N-dimethylethylenediamine (N,N-dimeEn) [Pt{(CH3)2N(CH2)2NH2}Cl2] (I) was synthesized. The reaction of the diamine with pyridine gave Pt(II) tetramine [Pt{(CH3)2N(CH2)2NH2}Py2]Cl2 (II), which was oxidized with chlorine to give Pt(IV) triamine Pt{[(CH3)2N(CH2)2}PyCl3]Cl · H2O (III). The reaction of III with chlorine (chloroamidation) yielded chloroimide [Pt{(CH3)2N(CH2)2NCl}PyCl3] (IV). The IR spectra of complexes I–IV and UV/Vis spectra of III and IV were studied. X-Ray diffraction analysis was performed for III (monoclinic crystals, space group P21/c, a = 7.7437(6), b = 8.1100(7), c = 28.52992(2) Å, β = 93.7280(10)°, Z = 4, R hkl = 0.0420) and IV (orthorhombic crystals, space group Pna21, a = 15.7825(12), b = 7.4447(6), c = 12.3099(6) Å, Z = 4, R hkl = 0.0539). During oxidation of Pt(II) tetramine with chlorine, the pyridine molecule is removed from the cis position relative to the (CH3)2N group (trans position relative to the NH2 group) of N,N-dimethylethylenediamine. The reaction of chloroimide complex IV with concentrated HCl (dechloroamidation) at 20°C afforded the initial complex III; that at 100°C, gave triamine III together with Pt(IV) diamine [Pt(N,N-dimeEn)Cl4] (V) (monoclinic crystals, space group P21/n, a = 7.1278(5), b = 11.5384(8), c = 12.7501(9) Å, β = 93.23(10)°, Z = 4, R hkl = 0.0239).  相似文献   

14.
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   

15.
用INDO系列方法对C602-与CH3反应的中间体C60(CH3)-进行理论研究,得到具有Cs对称性的构型。结果表明,CH3加成到C15上,将使与其相邻的双键碳(C30)的电荷密度和自旋密度达极大值,故加成反应部位在C30处;另外,C15的对位C12(或C27)也较其它部位易于反应,且有两个反应场所,因而产物C60(CH3)2可能为六元环上的1,2-加成和1,4-加成两种异构体的混合物。同时对两种加成产物的结构和电子光谱进行了理论研究,指认其电子跃迁,并讨论了其光谱红移的原因。  相似文献   

16.
Cs3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)] (I) and Cs5[UO2(CH3COO)3]3[UO2 (NCS)4(H2O)] · 2H2O (II) have been synthesized via the reaction between uranyl acetate and cesium thiocyanate in aqueous solution. According to single-crystal X-ray diffraction data, both compounds crystallize in monoclinic system with the unit cell parameters a = 18.7036(5) Å, b = 16.7787(3) Å, c = 12.9636(3) Å, β = 92.532(1)°, space group C2/c, Z = 4, R = 0.0434 (I); and a = 21.7843(3) Å, b = 24.6436(5) Å, c = 13.1942(2) Å, β = 126.482(1)°, space group Cc, Z = 4, R = 0.0273 (II). Uranium-containing structural units of compound (I) are mononuclear [UO2(CH3COO)3]? and [UO2(CH3COO)(NCS)2(H2O)]? moieties, which correspond to the AB 3 01 and AB01M 3 1 crystallochemical groups (A = UO 2 2+ , B01 = CH3COO?, M1 = NCS? and H2O). The structure of compound II is built of [UO2(CH3COO)3]? and [UO2(NCS)4(H2O)]2? complexes, which belong to the AB 3 01 and AM 5 1 crystallochemical groups, respectively. Uranium-containing complexes in both structures are linked into a framework by hydrogen bonds and electrostatic interactions with cesium cations. The IR spectra of compounds I and II agree well with X-ray diffraction data.  相似文献   

17.
用X-射线衍射法测定了[C5H4C(CH3)(C3H7)CH2CH= CH2]NdMg2(μ3-OH)(μ3-Cl)(μ2-Cl)3(THF)4Cl的晶体结构。它属三斜晶系,空间群为P1- ,a= 12.698(3), b= 13.616(3), c= 13.712(3), α= 68.91(3), β= 84.34(3), γ= 63.07(3)°, V= 1966(1)3, Mr= 849.74, Dx= 1.412 g·cm - 3, μ= 1.7297 m m - 1, F(000)= 840, Z= 2, R= 0.073, w R= 0.086(I≥3σ(I))。分子中Nd(Ⅲ)原子的配位数为八,形成一个严重扭曲的八面体结构。两个Mg 原子的配位情况相似,它们的配位数都是六,构成两个扭曲的八面体。这三个八面体通过三个共用平面联接  相似文献   

18.
The salts [RuII(L–L)3](CF3SO3)2 (L–L = bpy or phen) have been prepared in high yields via reactions of [RuII(DMF)6](CF3SO3)2 (DMF = N,N-dimethylformamide), generated in situ by reduction of [RuIII(DMF)6]-(CF3SO3)3, with an excess of bpy or phen at room temperature in DMF solutions.  相似文献   

19.
The synthesis of 1,5-bis(2-dihydroxyphosphoryl-4-ethylphenoxy)-3-oxapentane [(HO)2(O)P(C6H3CH2CH3)(OCH2CH2)2O(C6H3CH2CH3)P(O)(OH)2] (H4K2) and single crystal X-ray diffraction study of H4K2 · 2H2O (I) are described. The crystals are orthorhombic, a = 33.291(4) Å, b = 8.9374(10) Å, c = 8.1021(9) Å, V = 2410.6(5) Å3, Z = 4, space group Cmc21, R = 0.0484 for 2566 reflections with I > 2σ(I). In I, the molecules of H4K2 are hydrogen-bonded to two crystallographically independent H2O molecules to give neutral conglomerates H4K2 · 2H2O. The electroanalytical characteristics of poly(vinyl chloride) membranes based on H4K2 were tested. Cu2+ and Zn2+ complexes with H4K2 and Er3+, Nd3+, and complexes with H4K2, 1,5-bis[2-(dihydroxyphosphoryl-4-methoxy)phenoxy]-3-oxapentane, 1,5-bis[2-(dihydroxyphosphinyl)phenoxy]-3-oxapentane, and 1,8-bis[2-(dihydroxyphosphinyl)phenoxy]-3,6-dioxaoctane were prepared.  相似文献   

20.
The title compound has been synthesized by the reaction of HgI2 and [(CH3)3- NCH2CH2N(CH3)3]I2 with pH = 7.5 at room temperature, and its crystal structure was determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in monoclinic system, space group P21/c with a = 8.3075(8), b =15.8084(19), c =15.390(2)(°A), β = 95.192(4)o, V = 2012.9(4)(°A)3, Z = 2, Dc = 2.824 g/cm3, F(000) = 1502, C14H39N4O2Hg2I8, Mr = 1711.87, μ(MoKα) = 13.768 mm-1, the final R = 0.0465 and wR = 0.1293 for 3046 observed reflections with I > 2(I). The title compound consists of cations ([C8H22N2]2+) and anion (HgI42-), which are combined by static attracting forces to form the so-called organic-inorganic hybrid material.  相似文献   

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