共查询到20条相似文献,搜索用时 15 毫秒
1.
The condensation products of 5-methyl-3-phenyl-1 H-indole-2-carbohydrazide (1) with 2-butanone, 3-pentanone and cyclopentanone were prepared. The adducts (2a-c) were characterized by microanalysis, UV, IR, 1H NMR, 13C NMR and EI mass spectrometry. 1H NMR spectra of 2a and 2b revealed rotational restriction about the C–N bond in solution (DMSO-d 6) and displayed double resonances associated with the CH 3 and CH 2CH 3 residues of the alkylidene moieties. A variable temperature 1H NMR experiment was run on 2a to overcome the rotational barriers and thus determine the coalescence temperature but no coalescence was observed up to 77 °C. The structural analysis of 2a and 2c were also carried out by single crystal X-ray diffraction and confirmed by theoretical calculations (semiempirical PM3 and ab initio RHF/6-31G(d)). 相似文献
2.
Gaussian-2 ab initio calculations were performed to examine the six modes of unimolecular dissociation of cis-CH 3CHSH + (1 +), trans-CH 3CHSH + (2 +), and CH 3SCH 2+ (3 +): 1 +→CH 3++ trans-HCSH (1); 1 +→CH 3+ trans-HCSH + (2); 1 +→CH 4+HCS + (3); 1 +→H 2+ c-CH 2CHS + (4); 2 +→H 2+CH 3CS + (5); and 3 +→H 2+ c-CH 2CHS + (6). Reactions (1) and (2) have endothermicities of 584 and 496 kJ mol −1, respectively. Loss of CH 4 from 1 + (reaction (3)) proceeds through proton transfer from the S atom to the methyl group, followed by cleavage of the C–C bond. The reaction pathway has an energy barrier of 292 kJ mol −1 and a transition state with a wide spectrum of nonclassical structures. Reaction (4) has a critical energy of 296 kJ mol −1 and it also proceeds through the same proton transfer step as reaction (3), followed by elimination of H 2. Formation of CH 3CS + from 2 + (reaction (5)) by loss of H 2 proceeds through protonation of the methine (C H) group, followed by dissociation of the H 2 moiety. Its energy barrier is 276 kJ mol −1. On both the MP2/6-31G* and QCISD/6-31G* potential-energy surfaces, the H 2 1,1-elimination from 3 + (reaction (6)) proceeds via a nonclassical intermediate resembling c-CH 3SCH 2+ and has a critical energy of 269 kJ mol −1. 相似文献
3.
The mechanism and kinetics for the reaction of propene(CH 3CH=CH 2) molecule with O( 1D) atom were investigated theoretically. The electronic structure information of the potential energy surface(PES) was obtained at the B3LYP/6-311+G(d,p) level, and the single-point energies were refined by the multi-level MCG3-MPWB method. The calculated results show that O( 1D) atom can attack CH 3CH=CH 2 via the barrierless insertion mechanism to form four energy-riched intermediates CH 3C(OH)CH 2(IM1), CH 3CHCHOH(IM2), CH 2OHCHCH 2(IM3) and cyclo- CH 2OCHCH 3(IM4), respectively, on the singlet PES. The branching ratios as well as the pressure- and temperaturedependence of various product channels for this multi-well reaction were predicted by variational transition-state and Rice-Ramsperger-Kassel-Marcus(RRKM) theories. The present results will be useful to gain a deep insight into the reaction mechanism and kinetics of CH 3CH=CH 2+O( 1D) reaction. 相似文献
4.
噻唑硫酮因具有独特的生物活性,使其在医学和杂环化学等领域有着广泛的应用,从而引起了科研工作者的研究兴趣。本文以离子液体1-丁基-2, 3-二甲基咪唑鎓醋酸盐(BmmimOAc)为催化剂,2-芳氨基乙醇和二硫化碳为起始原料,一步缩合合成3-芳基-2-噻唑硫酮。以2-苯氨基乙醇和二硫化碳的反应为模型,考察了一系列离子液体的催化活性。发现只有阴离子为醋酸根的离子液体才具有催化活性,这可能是由醋酸根的碱性所导致的。在这些阴离子为醋酸根的离子液体中,BmmimOAc的催化活性最高。以其为催化剂,系统考察了反应时间、反应温度、催化剂用量以及二硫化碳和2-苯氨基乙醇摩尔比对该反应的影响。得到最优的反应条件:反应时间6 h、反应温度130 ℃、10%的BmmimOAc用量以及5 : 1的二硫化碳和2-苯氨基乙醇摩尔比。在该反应条件下,目标产物3-苯基-2-噻唑硫酮的收率达到了97%。以不同的2-芳氨基乙醇为原料,考察了该反应的普适性。结果表明无论是具有给电子基团、吸电子基团或较大空间位阻的2-芳氨基乙醇均可顺利地与二硫化碳反应生成相应的3-芳基-2-噻唑硫酮,且分离收率高达83%–95%。核磁共振波谱和质谱分析表明反应过程中BmmimOAc的醋酸根阴离子可以自发地与二硫化碳反应生成硫代醋酸根阴离子,因此离子液体1-丁基-2, 3-二甲基咪唑鎓硫代醋酸盐(BmmimCOS)可能是2-芳氨基乙醇和二硫化碳反应的催化剂。通过核磁共振波谱研究了BmmimCOS与反应底物2-苯氨基乙醇和二硫化碳之间的相互作用,发现BmmimCOS与2-苯氨基乙醇之间存在氢键相互作用。在反应过程中硫代醋酸根阴离子通过氢键作用活化2-苯氨基乙醇,从而促进反应高效进行。基于表征结果,提出了一个可能的反应机理。首先,BmmimOAc自发地与二硫化碳反应生成BmmimCOS。然后,BmmimCOS中的硫代醋酸根阴离子通过氢键作用活化2-苯氨基乙醇。随后,活化的2-苯氨基乙醇与二硫化碳反应生成中间体。最后,中间体分子内环化生成目标产物3-苯基-2-噻唑硫酮。 相似文献
5.
利用自制的实验系统进行了醋酸溶液中低浓度瓦斯催化氧化制甲醇研究。实验结果表明,以Pd(OAc) 2为催化剂,反应体系中添加对苯醌或四氯对苯醌可改善甲烷活化环境,四氯对苯醌对瓦斯催化氧化过程的作用效果好于对苯醌。四氯对苯醌用量、反应压力和反应温度对瓦斯催化氧化具有重要影响。甲醇生成量随四氯对苯醌用量、反应压力和反应温度升高而增加。CH 3OH是通过反应过程中产生的H 2O 2与CH 4相互作用形成的。CH 3COOCH 3一部分是由Pd 2+直接氧化CH 4得到的;另一部分是由CH 3OH与反应溶剂CH 3COOH通过酯化反应形成的。 相似文献
6.
Modified Mannich reactions of amines, amino acids and a model peptide with Ph 2PH and CH 2O gave bis(diphenylphosphinomethyl)amines (Ph 2PCH 2) 2NR [R=Ph (1), CH 2CH 2OH (2), CH 2COOCH 2Ph (3), CH 2CONHCH 2COOCH 2Ph (4), CH 2COOH (5)] and (Ph 2PCH 2) 2NCH 2CH 2N(CH 2PPh 2) 2 (6). Reaction with [ReBr 3(CO) 3] 2− under mild conditions led to [ReBr(CO) 3]{(Ph 2PCH 2) 2NR} [R=Ph (7), CH 2CH 2OH (8), CH 2COOCH 2Ph (9), CH 2CONHCH 2COOCH 2Ph (10), CH 2COOH (11)] and [ReBr(CO) 3(Ph 2PCH 2) 2NCH 2] 2 (12). All new complexes have been characterized by NMR and IR spectroscopy and for 7, 9 and 10, single-crystal X-ray diffraction analyses. Electrospray mass spectrometric studies show that the rhenium–phosphine chelates are very stable, especially in neutral methanolic solution. Hydrolysis of the ester and amide linkages slowly occur in acidic and basic solutions over several weeks; displacement of the bromide ligand also occurs in basic medium. Cytotoxicity testing of 7–10 and 12 showed that all the complexes are active against specific tumor cell lines, especially MCF-7 breast cancer and HeLa-S 3 suspended uterine carcinoma. 相似文献
7.
以 β-硝基苯乙烯衍生物为底物, 二溴海因为氮源/卤素源, 乙腈作溶剂, 建立了碳碳双键上高度区域选择性氨溴加成反应新体系. β-硝基苯乙烯衍生物与二溴海因在室温无水碳酸钠催化下反应, 可高收率获得邻位氨溴加成产物, 最高收率达97%; β-甲基 -β-硝基苯乙烯衍生物在氢氧化钾催化下回流反应, 也可高收率得到邻位氨溴加成产物, 最高收率达95%. 实验结果表明, 对于硝基苯乙烯衍生物, 当苯环4-位具有强供电子基团如CH 3O时, 可以得到单一的 α-氨基 -β-溴加成产物, 但其收率相对较低; 当硝基苯乙烯衍生物的苯环4-位有强吸电子基团如NO 2时, 反应收率则很高. 这一实验结果证明 β-硝基苯乙烯衍生物(缺电子烯烃)与二溴海因的氨溴加成反应具有亲核加成的特征. 本文共考察了20种不同结构的 β-硝基苯乙烯衍生物的氨溴加成反应情况, 其产物结构经核磁共振波谱及质谱分析确证, 并提出了可能的反应机理. 相似文献
8.
Powder X-ray diffraction, 119Sn NMR spectra, and 1H NMR spin–lattice relaxation times, T1, were measured for (CH 3) nNH 4−nSnCl 3 ( n=1–4). From the Rietveld analysis, it is shown that all four compounds crystallize into deformed perovskite-type structures at room temperature. The temperature dependence of 1H T1 was analyzed in terms of the CH 3 reorientation and other motions of the whole cation. Except for the phase transition in CH 3NH 3SnCl 3, which is from monoclinic to rhombohedral at 331 K, 1H T1 was continuously changed at other phase transitions in this compound as well as in the n=2–4 compounds, suggesting that the transitions are not caused by the change of the motional state of the cation but by an instability of the [SnCl 3] nn− perovskite lattice. 相似文献
9.
The Ca( 1D 2, 3P J) + CH 3 → CaI(A,B) + CH 3 reactions system has been studied by measuring its chemiluminescence under beam-gas conditions. Absolute values of the state-to-state reaction cross-sections were determined at low collision energy
. In addition, the electronic branching ratio and product energy disposal have been determined for each metastable reaction. The major changed observed in the chemiluminescence when comparing the Ca( 1D 2) reaction versus that of Ca( 3P J) is the total yield associated with the former reaction. To the best of our spectral resolution neither the electronic branching ratio e.g. CaI(A)/CaI(B) nor the internal CaI energy disposal change significantly as the metastable Ca( 1D 2)/Ca( 3P J) ratio is varied. In spite of the fact that the Ca( 3P J) reaction is less exoergic, the CaI product appears with a higher fraction of internal energy than that of Ca( 1D 2) reaction. Thus, the fraction of the total energy appearing in CaI internal energy amounts to 57.5% in the Ca( 3P J) reaction while it is 19.3% only for the Ca( 1D 2) reaction. This difference is discussed in the light of a distinct mechanism associated with the attack of the excited Ca atom into the C---I bond. No significant chemiluminescence yield was found for the energetically open CaCH *3 channels. The product chemiluminescence polarization was also measured as a function of the metastable concentration. A significant degree of polarization was found depending upon the specific electronic excitation. The analysis of the polarization emission associated to the parallel CaI(X 2Σ+ ← B 2Σ+) emission led into a strong polarization of the product rotational angular momentum. The comparison of the product rotational alignment for the kinematically identical Ca(1D2, 3PJ, 1P1) + CH3 → CaI* (B2Σ+) + CH3 reaction system showed that the CaI rotational polarization diminishes in the 3PJ → 1D2 → 1P1 sequence, e.g. as the reaction exothermicity increases. In addition the degree of polarization associated with other emission bands as for example CaI(X 2Σ+ ← A 2Π1/2) indicates the presence of a parallel transition which was been interpreted as mixing of Hund's case (a) and (c) appropriate for this heavy CaI diatom produced with a high rotational excitation. 相似文献
10.
合成了1,3-丙二胺邻苯二酚钼钨手性八面体配合物(NH 3CH 2CH 2CH 2NH 2) 2[Mo 0.4W 0.6O 2(C 6H 4O 2) 2],并对其进行了单晶结构解析,研究了其与ATP作用的液相NMR谱.该晶体属正交晶系,空间群为Pcan.晶胞参数a=0.7501(2)nm,b=2.3994(7)nm,c=1.2178(4)nm,Z=4.[Mo 0.4W 0.6O 2(C 6H 4O 2) 2] 2-的配位几何构型为手性八面体,晶体为外消旋体.配位阴离子中MoW中心金属离子除了与两个端基O配位形成cis-MO键外,同时还分别与两个邻苯二酚配位基团的的氧原子配位,形成4个M-Ob(M=Mo,W)键,构成两个五元环.利用 1HNMR, 13CNMR, 31PNMR以及 1H- 15NHMBC对标题配合物及其与ATP在D 2O溶剂中的作用进行了研究,发现标题配合物的MoW中心金属离子在纯D 2O溶剂中被还原成+5价,但与ATP混合后转化为+6价,且与原配位基邻苯二酚发生解离.解离后的[MO 2] 2+最大可能与腺嘌呤上的氨基N原子配位,而此配位可能是其抗癌抗肿瘤活性的主要作用机理之一. 相似文献
11.
用NMR法研究了顺二氨二水合铂(Ⅱ)(AAP)与α-二棕搁酸磷脂酰胆碱(DPPC)的相互作用方式,以阐明在顺铂-细胞相互作用中膜磷脂的贡献。 1H及 13C谱表明,DPPC与AAP在CDCl 3中作用时,铂结合在DPPC的头部并引起DPPC分子中gauche向trans的构象转变。65℃测定DPPC脂质体与AAP在D 2O溶液中反应不同时间后的-N(CH 3) 3、-(CH 2) n及-CH 3基团 1H的T 1值表明,铂在磷脂上的结合引起的磷脂构象变化会导致膜分子重新装配。 相似文献
12.
以胜利褐煤为研究对象,利用XRF、FT-IR等手段,采用灰分、pH值、不同相对蒸气压下的复吸水含量等参数,研究了Ca2+的离子效应对褐煤在不同相对蒸气压下复吸水含量的影响。研究结果表明,煤中Ca2+的负载量随用于交换的钙离子溶液浓度的增大而增加。煤中Ca2+的负载量对煤样的平衡复吸水含量影响较大,Ca2+负载量越大,煤样的平衡复吸水含量越大。相对蒸气压高于92%平衡复吸水含量的主要控制因素为游离水分子与游离水分子之间的相互作用力。相对蒸气压在11%~92%平衡复吸水含量的主要控制因素为金属水簇Ca+(H2O)n与毛细管之间的毛细管作用力。 相似文献
13.
在G3MP2B3结构优化和能量计算的基础上, 采用RRKM理论和疏松过渡态模型重新估算了过氧硝酸乙酰酯(PAN)的热分解反应PAN→CH 3C(O)OO+NO 2(R1)的反应速率常数, 得到与实验值吻合的结果.用同样的模型计算了PAN→CH 3C(O)O+NO 3(R2)的反应速率常数. 结果表明, 在相同的反应条件下, R1是主要的分解通道, R2是次要通道, R2的反应速率常数比R1的小两个数量级. 相似文献
14.
The reaction of singlet oxygen with a variety of allyltin compounds CH 2=CHCH 2SnR 3 (R 3 = Me 3, Bu 3, allyl 3, (cyclo-C 6H 113, Ph 3, allylBu 2, Bu 2Cl, Bu 2OAc, allylCl 2, allylCl 2bipy) has been investigated, and the allylperoxytin compounds, 3-stannylallyl hydroperoxides, and 4-stannyl-1,2-dioxolanes which result from M-ene, H-ene and cycloaddition processes, respectively, have been identified by NMR spectroscopy. As the tin centre becomes more electropositive, as indicated by the 13C NMR shift of the allylic CH 2 group, the proportion of the M-ene reaction increases, and when δCH 2 is above about 23.7, the allylperoxytin compound is the only product. An exception to this rule is tetraallyltin, δCH 2 16.13, which similarly shows only the M-ene reaction. This is tentatively ascribed to the special effect of hyperconjugation between the C---Sn σ-bond and the remaining π-systems. A polar solvent favours the M-ene reaction. The cycloaddition reaction is favoured by low temperature, and at − 70°C in a non-polar solvent it may become the major route. Diallylmercury and allylmercury chloride react with singlet oxygen to show only the M-ene reaction, but also undergo extensive photosensitized decomposition. With 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), allylmercury chloride shows only the M-ene reaction. 相似文献
15.
The synthesis and characterization of naptho-9-crown-3, N9C3, as a novel 9-membered ring crown ether with greater lipophilicity than that of benzo-9-crown-3, B9C3, is reported. The solution AA′BB′ pattern of –CH 2O– protons in N9C3 is close to that of B9C3. The solid-phase 13C CPMAS NMR, as a tool for conformation prediction, reveals that the solid-phase conformation of the 9-membered ring crown cavity in N9C3 is different from B9C3, the two key C2O2CH 2 and C3O1CH 2 units are predicted to be out of naphthalene plane, and the two C1C2O2CH 2 and C4C3O1CH 2 torsion angles are close to each other. 相似文献
16.
A degradable polycation with high density of discrete charge was synthesized from tetraethylenepentamine (TEPA) and ethylene glycol diacrylate (EGDA) based on Michael addition and amidation. The cationic polymer synthesized here was denoted as PTE. Polymerization was monitored by 1H NMR spectroscopy. According to 1H NMR spectra, Michael addition proceeded more rapidly than amidation. After 6 h, there were no double bonds left, while amidation existed throughout the polymerization. In addition, when PTE was synthesized in chloroform and dichloromethane, respectively, there were some structural differences as shown by 1H NMR spectroscopy. The degradation laws of PTE in aqueous solution were studied by 1H NMR and viscosity measurements. When PTE was dissolved in deionized water, degradation proceeded in high velocity. However, in NaH 2PO 4 aqueous solution, degradation was slowered. Degradation at 37 °C proceeded obviously more rapidly than that at 25 °C. A certain degree of amidation facilitated the reduction of degradation velocity. The effect of concentration on degradation was not obvious. Interestingly, PTE synthesized in CHCl 3 was degraded more rapidly than that in CH 2Cl 2. 相似文献
17.
1,1-Bis(trimethylsilyl)-2-phenylethylene (1), which has been synthesized from the Peterson reaction between (Me 3Si) 3CLi and benzaldehyde, reacts with various acyl chlorides (RCOCl, R = Me, Et, iso-Pr, n-Bu, iso-Bu, iso-C 5H 11, PhCH 2, PhCH 2CH 2) in the presence of AlCl 3 to give -silyl-,β-unsaturated enones 3a–3h with high E stereoselectivity along with trans-,β-unsaturated ketones 4a–4h. The enones 3 can be partially converted into the ketones 4 with an excess of AlCl 3. Reaction of 1 with RCOCl, (R = Ph, CH 3CH=CH) afforded only the ketones 4. Yields were dependent on time and the amounts of AlCl 3 used. 相似文献
18.
Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1+4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature.The structures of the products were characterized by IR,MS,^1H NMR,elemental analysis and single crystal X-ray diffraction analysis.A mechanism for the formation of products was also proposed. 相似文献
19.
Mercury compounds of the types HgR 1R (R 1 = C(SiMe 3) 3; R = Me, iPr, Bu, tBu or Ph) and HgR 2R(R 2 = C(SiMe 2Ph) 3; R = Me, Bu, CH 2Ph or Ph) have been prepared. Those containing R 1 were made by reactions of the bromides HgR 1Br with the Grignard reagents MgRX, and those containing R 2 by reaction of HgR 2Cl with LiR or, for R = CH 2Ph, with Mg(CH 2Ph)Cl. Replacement of one R group in HgR 2 by the bulky R 1 or R 2 group leads to a large increase in thermal stability, a marked shift in the 199Hg resonance to lower frequency and an increase in the coupling constant 1J( 13C--- 199Hg) for the Hg---R bond. The compound HgR 2Cl does not react further with LiR 2 in tetrahydrofuran, but with LiR 1 gives HgR 1R 2; the arrangement of the SiMe 2Ph groups in the latter in solution in CH 2C12 at low temperature appears to be different from that in the solid. 相似文献
20.
The reaction of [AuCl(PPh 3)] with Pb(SR) 2(R = C 2H 5, C 6H 5, CH 2C 6H 5, C 6F 5, C 6H 2Me 3-2,4,6, Pr i and Bu t) provides a clean method to obtain complexes of the type [Au(SR)(PPh 3)] in good yields. The new compounds have been characterized by IR, 1H, 31P, 19F and 31C NMR. A study by FAB mass spectrometry indicates that an ion-molecule aggregation process takes place. 相似文献
|