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1.
标题化合物(Me_2SiSiMe_2)[η ̄5-(3-Me_3SiC_5H_3)Fe(CO)_2]_2/(μ-CO)_2(A)分子中的Fe-Fe键被钠汞齐还原断裂,生成相应的双铁负离子,分别与MeCOCl、PhCOCl、PhCH_2Cl、ClCH_2COOC_2H_5和Ph_3SnCl进行亲核取代反应,生成在铁原子上引入相应取代基的产物(Me_2SiSiMe_2)[η ̄5-(3-Me_3SiC_5H_3)Fe(CO)_2R]_2(R:MeCO(1),PhCO(2),PhCH_2(3),CH_2COOC_2H_5(4),Ph_3Sn(5),I(6))。A在氯仿中与碘反应,得到Fe-Fe断裂的双铁碘化物,但在苯中与过量碘反应,则得到Fe-I-Fe桥联的离子型化合物(Me_2SiSiMe_2)[η ̄5-(3-Me_3SiC_5H_3)Fe(CO)_2]_2I·I(7)。化合物6的晶体和分子结构经X射线衍射测定,6属单斜晶系,P21/c空间群,a=1.7217(4)nm,b=0.7753(2)nm,C=1.3629(7)nm,β=103.80(3)°,V=1.767(2)nm3,Z=4,Dc=1.6299·cm-1,最终偏差因子R=0.054。  相似文献   

2.
1,2-二(三甲硅基环戊二烯基)四甲基二硅烷与Fe(CO)_5在二甲苯中于105~110℃反应除分离到少量标题化合物(Me_2SiSiMe_2)[η-(3-Me_3SiC_5H_3Fe(CO)]_2(μ-CO)_2(5)外,主要是生成了脱Me_3Si基的产物(Me_2SiSiMe_2)[η-C_5H_4Fe(CO)]_2(μ-CO)_2(1)及1的热重排异构体[Me_2SiC5H4-Fe(CO)_2]_2(2).将5的二甲苯溶液加热回流18h,则转化为其异构体[Me_2Si(Me_3SiC_5H_3)Fe(CO)_2]_2(6).脱硅基发生在由相应反应物制备5的过程中。且脱硅基是与反应物中(Me_2SiSiMe_2)桥的存在有关.5的晶体结构经X射线衍射测定属单斜晶系,P2_1/m空间群,晶体学数据:a=0.6780(1)nm,b=2.2303(9)nm,c=0.9988(1)nn,;β=98.96(1)°,V=1.4960nm~3.Z=2,D_c=1.36g/cm~3.  相似文献   

3.
用柠檬酸盐法合成出La_(1-_x)Sr_xFeO_3(x=0.1,0.2,0.3,0.4)原粉,再经固相反应得到纳米晶粉末,用TG、DTA、XRD、IR进行了表征,确证复合氧化物La_(1-_x)Sr_xFeO_3为钙钛矿型结构,粒径在10~25nm之间。实验结果表明,随着固相反应条件不同,产物粒径呈规律性变化.气敏特性研究表明,该纳米晶材料对乙醇有较高的选择性和灵敏度,其选择性顺序为La_(0.9)Sr_(0.1)FeO_3>LaFeO_3>LaFeO_3(大晶粒)。  相似文献   

4.
STUDYONREACTIONOF(μ_3-CCO_2Et)CO_2M(CO)_8(CpMe)(M=Mo,W)WITHNa_2[Fe(CO)_4].SYNTHESISOFTWOKINDSOFTHENOVELCLUSTERSEtO_2CCFeCoM(CO)_8...  相似文献   

5.
CuO/活性炭和Fe2O3/活性炭催化还原NO   总被引:4,自引:0,他引:4  
高志明  赵震 《应用化学》1996,13(4):77-79
CuO/活性炭和Fe_2O_3/活性炭催化还原NO高志明,赵震,杨向光,吴越(中国科学院长春应用化学研究所长春130022)关键词活性炭,还原,NO,氧化铜,氧化铁目前,对固定源的NO处理是采用V2O5/TiO2作催化剂,NH3作还原剂的选择催化还原方...  相似文献   

6.
用X射线衍射法测定了由η~5-MeO_2CC_5H_4)(CO)_3MoNa和[(η~5-MeO_2CC_5H_4)(CO)_2W]Fe-(CO)_3Co(Co)_3(μ_3-S)的等瓣置换反应所生成的手性簇合物──[(η~5-MeO_2CC_5H_4)(CO)_2Mo]-[(η~5-MeO_2CC_5H_4)(CO)_2W]Fe(CO)_3(μ_3-S)的分子结构及晶体结构。晶体属P1空间群,晶胞参数α=0.87162(5)nm,b=0.76218(4)nm,c=1.87111(8)nm;α=94.164(4)°,β=97.979(2)°,γ=99.108(2)°,Z=2,μ=5.9cm~(-1)。最终的一致性因子R=0.036,Rw=0.037.该簇合物含MoWFeS四面体簇核,其中Mo、W原子以1:1的比例无序地分占了四面体的2个顶点.  相似文献   

7.
通过SnCl_2对化合物Me_2Si[η~5-C_5H_4Fe(CO)]_2(μ-CO)_2(Ⅰ)中Fe-Fe键的插入反应以及Ⅰ被Na-Hg齐还原所生成的相应双铁负离子{Me_2Si[η~5-C_5H_4Fe(CO)_2]_2}~(2-)与SnR_2Cl_2(R=Me,Ph)的亲核反应,合成了环状化合物Me_2Si[η~5-C_5H_4Fe(CO)_2]_2SnR_2[R=Cl(1),Me(2),Ph(3)]。以元素分析、IR和~1HNMR谱表征了它们的结构,并用X射线衍射测定了配合物3的晶体结构。3为单斜晶系,空间群P2_1/n,a=1.0384(3)nm,b=1.6384(1)nm,c=1.5762(5)nm,β=97.93(2)°,V=2.656(2)nm~3,Z=4,Dx=1.71g/mL。  相似文献   

8.
研究了含汞三金属化合物[η_5-RC_5H_4(CO)_3M]_2Hg(M=Mo,W;R=Me,Et,CO_2Me,CO_2Et)与锌粉的置换反应,发现当取代基R为给电子的Me和Et时底物不发生反应,而取代基R为拉电子的CO_2Me和CO_2Et时,则底物中的汞可被锌置换,生成带有机官能团的三金属化合物[η_5-RC_5H_4(CO)_3M]_2Zn;另外,还发现R为CO_2Et,M为Mo的产物[η_5-RC_5H_4(CO)_3M]_2Zn可在室温下被分解为相应的氯代物η_5-EtO_2CC_5H_4MoCl.  相似文献   

9.
ANOVELREACTIONBETWEENGe-GeANDFe-FeBONDSINCOMPLEX(Me_2GeGeMe_2)[(η~5-C_5H_4)Fe(CO)]_2(μ-CO)_2ANDCRYSTALSTRUCTUREOFTHEPRODUCT¥XiuT?..  相似文献   

10.
含Ce的水热体系中结构稳定性及变价现象   总被引:6,自引:3,他引:6  
利用XRD、IR及XPS谱研究了含Ce的水热体系中产物及其经过各种后处理的样品结构稳定性及Ce离子的价态变化。结果表明,不同的原料导致Ce离子稳定于不同的价态,如直接形成包括纳米晶在内的CeO2及一新相CeOHCO3,样品CeOHCO3经2GPa的冷压处理未发生结构转变,经高温焙烧处理得到具有高结晶度的棕红色的CeO2,当初始原料为Ce2(SO4)3和Ce(NO3)3时,产物为CeO2;而当初始原  相似文献   

11.
CeO2纳米晶的光伏特性和量子尺寸效应   总被引:7,自引:0,他引:7  
对制备的CeO2纳米晶进行了反射吸收光谱研究,对其在300-450nm的宽带吸收指认为O2p→Ce4f电荷转移跃迁,发现这个吸收带随着样品粒径变小而红移,利用表面光电压谱方法和场调制表面光电压谱方法不同粒径的CeO2纳米晶的光伏特性进行了研究。并对吸收谱带进行了解析。当样品粒径达到纳米尺寸时,在CeO2价带上大约0.9eV处明显地形成一个新能带。这个能带具有较强的定域性,在相应的跃迁的过程中产生具  相似文献   

12.
Nitrophenols and methylnitrophenols have been identified as photolytic precursors of nitrous acid, HONO, but their gas-phase absorption has not previously been reported. In this study, the absorption cross sections of 2-nitrophenol, 3-methyl-2-nitrophenol, and 4-methyl-2-nitrophenol were measured from 320 to 450 nm using incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS). The benzaldehyde absorption spectrum was measured to validate the approach and was in good agreement with literature spectra. The nitrophenol absorption cross sections are large (ca. 10(-17) cm(2) molecule(-1)) and blue-shifted about 20 nm compared to previously measured solution spectra. Besides forming HONO, nitrophenol absorption influences other photochemistry by reducing the available actinic flux. The magnitudes of both effects are evaluated as a function of solar zenith angle, and nitrophenol absorption is shown to lower the photolysis rates of O(3) and NO(2).  相似文献   

13.
High resolution electronic absorption spectra of aniline and anilino free radical have been recorded in the vapor phase at room temperature by flash photolysis technique, and subsequent reactions have been investigated by kinetic spectroscopy. It was possible to follow the kinetics of the anilino radical's decay which occurred predominantly by bimolecular recombination. Decay parameters of anilino free radical were measured from the absorption bands.  相似文献   

14.
有效的染料激光操作需要较高的荧光量子效率,若丹明是在500~700 nm光谱区中一类最重要的激光染料.然而,染料的基态分子和三线态对辐射能量的吸收将会大大降低激光输出效率,再者,由于若丹明类染料在紫外区的吸收系数较小,为了有效吸收泵浦能量(如用XeCI准分子激光,308 nm),就必须使用高浓度染料溶液,在这种情况下,若丹明类染料较小的Stokes位移就势必造成基态分子更大的重复吸收,即造成更大的谐振腔损耗[1].  相似文献   

15.
The polarized absorption and ESR spectra of the acridine C-radical have been measured at room temperature, the radical was produced at 77 K by γ-ray irradiation of a stretched polyvinyl alcohol film saturated with acridine. The dichroism of the absorption spectrum has been well explained by the results of MO calculations for the acridine C-radical.  相似文献   

16.
Two tunable dye lasers, with differing wavelength and polarization, were synchronized to produce a two-photon spectrum in gas phase benzene. Simultaneous absorption of two photons from one laser beam was precluded by choosing appropriate wavelengths. All possible ratios have been measured for a totally-symmetric two-photon transition demonstrating a strong analogy between two-photon absorption and Raman scattering.  相似文献   

17.
The radicals formed in the flash photolysis of 2-methylbut-1-ene and subsequent reactions have been investigated by kinetic spectroscopy and gas liquid chromatography. Less than 10% of photo products are formed by a molecular made of fission of the excited olefin, and of the radical modes the relative probabilities of band fission, beta(CH):beta(CH):alpha(CC) are 13:1.37:1. The extinction coefficients of beta-methallyl radical measured experimentally for all the absorption bands. The decay of the beta-methallyl radical was second order. The rate constant for the beta-methallyl radical recombination experimentally measured was 2.6+/-0.3 x 10(10) l mol(-1)s(-1) at 295+/-2K. The spectrum image showing the absorption bands was examined by image processing techniques in order to improve the visual experience of each band by localizing to a specific region of interest. Experimental results illustrate how the exact location of absorption bands was clearly extracted from the spectral image and further improvements in the visual detection of absorption bands.  相似文献   

18.
Photosynthetic organisms have light-harvesting complexes that absorb and transfer energy efficiently to reaction centers. Light-harvesting complexes (LHCs) have received increased attention in order to understand the natural photosynthetic process and also to utilize their unique properties in fabricating efficient artificial and bio-hybrid devices to capture solar energy. In this work, LHCs with different architectures, sizes, and absorption spectra, such as chlorosomes, Fenna–Matthews–Olson (FMO) protein, LH2 complex, and phycobilisome have been characterized by an electrospray-scanning mobility particle-sizer system (ES-SMPS). The size measured by ES-SMPS for FMO, chlorosomes, LH2, and phycobilisome were 6.4, 23.3, 9.5, and 33.4?nm, respectively. These size measurements were compared with values measured by dynamic light scattering and those reported in the literature. These complexes were deposited onto a transparent substrate by electrospray deposition. Absorption and fluorescence spectra of the deposited LHCs were measured. It was observed that the LHCs have light absorption and fluorescence spectra similar to that in solution, demonstrating the viability of the process.  相似文献   

19.
The kinetics and absolute rate constants of the gas-phase reaction of the hydroxymethyl radical (CH2OH) with molecular oxygen have been studied using laser photolysis/near-IR absorption spectroscopy. The reaction was tracked by monitoring the time-dependent changes in the production of the hydroperoxy radical (HO2) concentration. For sensitive detection of HO2, two-tone frequency modulation absorption spectroscopy was used in combination with a Herriott-type optical multipass absorption cell. Rate constants were determined as a function of temperature (236 K相似文献   

20.
The copolymerization of isoprene with styrene initiated with sec-butyllithium in cyclohexane solution has been studied by kinetic methods. The rates of the homopolymerization have been measured by normal methods. The rates of the cross-propagation reactions were measured by the rate of appearance or disappearance of the ultraviolet absorption of polystyryllithium when the individual chain ends were reacted with the opposite monomer in the absence of the first. The rates of some of the reactions were also measured in the presence of the other monomer. It was found that polyisoprenyllithium reacted with both monomers with a one quarter-order dependence, and the polystyryllithium with a one half-order dependence. It was found possible to describe the copolymerization in terms of the four individual rate constants and to predict the initial copolymer composition. It was not found necessary to resort to explanations based on preferential absorption of isoprene around the chain ends to explain the high isoprene content of the copolymer.  相似文献   

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