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1.
合成了三种以2-溴代对苯二甲酸为桥联配体的新型双核钴(Ⅱ)的配合物,即[Co2(BTP)(phen)4](ClO4)2.H2O(配合物1)、[Co2(BTP)(Nphen)4](ClO4)2.2H2O(配合物2)和[Co2(BTP)(Bpy)4]ClO4)2,2HO(配合物3)(BTP=2-溴代对苯二甲酸根,phen=1,10-菲罗啉,Nphen=5-硝基-1,10-菲罗啉,Bpy-2,2'联吡啶  相似文献   

2.
六核配合物[Mn6O2(O2CPh)10(py)4]·MeCN的合成及结构   总被引:1,自引:0,他引:1  
将[Mn3O(O2CPh)6(py)2(H2O)]·0.5MeCN、水杨醛缩邻氨基酚和三乙胺在乙腈溶液中反应,合成了六核锰配合物。经X射线单晶结构分析确定该配合物晶体的化学结构式为[Mn6O2(O2CPh)10(py)4]·MeCN。结构中含有一个[Mn6O2]10+核,可看成是两个[Mn4(μ4-O)]四面体共一条边,每个四面体的中心是一个μ4-O2-离子。晶体属单斜晶系,P21/a空间群,晶胞参数a=2.0572nm,b=1.8520nm,c=2.5375nm,β=111.82°,V=8.975nm3,Z=4,最终偏差因子R=0.0632,Rw=0.0595。  相似文献   

3.
用INDO系列方法研究了C60的哌嗪衍生物C60N2(C2H4)2的结构。结果表明[6,6],异构体具有C2v对称性[6,5],异构体具有Cs对称性,前者能量较低。以优化构型为基础,计算两种加成产物的UV谱,结果表明,[6,6]异构体的特征吸收与实验值相符,同时对[6,5]异构体的UV谱进行理论预测,对电子跃迁进行了理论指认,并分析了光谱红移的原因。  相似文献   

4.
合成了三种以2-溴代对苯二甲酸根为桥联配体的新型双核钴(Ⅱ)的配合物,即[Co2(BTP)(phen)4](ClO4)2·H2O(配合物1)、[Co2(BTP)(Nphen)4](ClO4)2·2H2O(配合物2)和[Co2(BTP)(Bpy)4](ClO4)2·2H2O(配合物3)(BTP=2-溴代对苯二甲酸根,phen=1,10-菲罗啉,Nphen=5-硝基-1,10-菲罗啉,Bpy=2,2′-联吡啶)。使用元素分析、IR、UV-Vis光谱和电导测定方法对该配合物进行了表征。测定了配合物的变温磁化率,并对所得数据进行了理论分析,求得了配合物1、配合物2和配合物3的自旋磁交换积分分别为:2J=-6.5cm-1,2J=-7.8cm-1和2J=-8.9cm-1。对该三配合物进行了体外抗人白血病癌细胞的实验。发现该三配合物均具有一定的抑制癌细胞的活性  相似文献   

5.
卢绍芳  黄建全 《结构化学》1996,15(6):415-421
[Mo3(μ3-O)(μ-S)3(μ-OAc(dtp)3(py)]和[Mo3(μ-S)3(μ-OAc(dtp)3-(py)](dtp=S2P(OC2H5)2^-)族合物分别与金属化合物BiI3和SbBr3进行原子簇反应均能获得意外产物{[Mo3(μ3-S)(μ-S2)2(dtp)3](μ3-S)(η^3-S2)[Mo2(μ3-S)(μ-S)3(μ-OAc)(dtp)2]}六核钼簇。其结构实际上是由  相似文献   

6.
以4种甲基取代戊二烯基为配体合成了4个过渡金属钒开环夹心羰基配合物[2,4-(CH3)2C5H5]2VCO(I),[2,3-(CH3)2C5H5]VCO(Ⅱ),[2-CH3C5H6]2VCO(Ⅲ)和[3-CH3C5H6]2VCO(Ⅳ),其中Ⅱ,Ⅲ,Ⅳ为新配合物,用X射线单晶衍射,IR,EPR法对所合成配合物进行了结构表征,发现I具有两种晶相。  相似文献   

7.
SynthesisandCrystalStructureofPyridine-2-thiolato-MolybdenumComplex[Et_4N][Mo(CO_4)(pyS)]YuPei-Hua;HuangLiang-Ren;ZhuangBo-Tao...  相似文献   

8.
TiO2纳米粒子膜表面性质的研究   总被引:14,自引:0,他引:14  
TiO_2纳米粒子膜在光催化降解大气和水中的污染物[1]、光电转换[2]、光致变色[3]等方面有广阔的应用前景,近年来受到了科学界的高度重视.研究表明,膜的表面性质对如上应用有着重要影响.本文采用等离子体化学气相沉积法(PECVD法)[4]制备了TiO2的纳米粒子膜,分别采用TiCl4等离子体或O2等离子体处理膜表面,获得两种不同表面性质的TiO2纳米粒子膜;并利用表面光电压谱(SPS)和电场诱导表面光电压谱(EFISPS)技术对膜的表面性质进行具体分析,探讨了其在光催化领域的可能应用.1实验部…  相似文献   

9.
As-V-O簇合物对乙苯选择氧化反应的催化活性   总被引:3,自引:0,他引:3  
通过水热方法合成了簇合物[N(CH3)4]4[As8V14O42(8H2O)]及其相近的同多及杂多钒氧簇K6V10O28·9H2O,NaKV2O6,(H2En)0.5V2O5,(H2En)3(VO)9(PO4)8,Na3VO(HPO4)(PO4)·H2O.运用XRD和IR等手段表征了[N(CH3)4]4[As8V14O42(8H2O)]的结构.该类化合物对于催化乙苯过氧化氢选择氧化制苯乙酮具有较高的催化活性.通过比较含钒与不含钒化合物的活性情况,讨论了催化氧化的活性中心.  相似文献   

10.
用INDO/CI方法研究了含有Fe-Fe键的原子簇体系[Fe2S2X4]^2-(X=Cl,Br,I)的电子光谱及电子结构,对于这些多谱带体系,谱带波数计算值与实验值符合,在谱带的指认分析中,发现了πd^1→πd等新的跃迁方式,对跃迁方式作了解释和分类,并讨论了谱带的电荷转移性质,此外,还对体系的化学键等性质进行了分析。  相似文献   

11.
CH自由基多光子电离新观测到3个nd Rydberg态   总被引:1,自引:1,他引:0  
(2+1) resonant multiphoton ionization of photolytically produced CH radical yields previously unobserved bands arising from two-photon transition to Rydberg states. Analysing of the spectrum of CH+, three new states are identified. They are 8 d, 9 d and 10 d Rydberg states, respectively.  相似文献   

12.
CH自由基多光子电离新观测到3个ndRydberg态   总被引:1,自引:1,他引:0  
由于CH自由基在星际空间、燃烧过程和有机化学反应中大量存在,而且CH自由基是量子化学计算中的模型分子,是人们研究的主要目标之一.几十年来,人们对它进行了大量研究.Herzberg等t‘’利用闪光光解研究了CH自由基紫外及真空紫外区域的发射谱,除了标识一些价键态外,还观察到了一些Rydberg态的发射.此后,Chupka等[’-‘]通过光解乙烯酮产生CH自由基,利用共振增强多光子电离光谱和光电子谱研究了CH在50000-75000cm-‘范围的价键态和Rydberg态.最近,理论计算表明l’I,CH的Rydberg态受排斥态的作用而发生预离解,但预离…  相似文献   

13.
The VUV absorption spectrum of fenchone is re-examined using synchrotron radiation Fourier transform spectrometry, revealing new vibrational structure. Picosecond laser (2+1) resonance enhanced multiphoton ionization (REMPI) spectroscopy complements this, providing an alternative view of the 3spd Rydberg excitation region. These spectra display broadly similar appearance, with minor differences that are largely explained by referring to calculated one- and two-photon electronic excitation cross-sections. Both show good agreement with Franck-Condon simulations of the relevant vibrational structures. Parent ion REMPI ionization yields with both femtosecond and picosecond excitation laser pulses are studied as a function of laser polarization and intensity, the latter providing insight into the relative two-photon excitation and one-photon ionization rates. The experimental circular-linear dichroism observed in the parent ion yields varies strongly between the 3s and 3p Rydberg states, in good overall agreement with the calculated two-photon excitation circular-linear dichroism, while corroborating other evidence that the 3pz sub-state plays no more than a very minor role in the (2+1) REMPI spectrum. Vibrationally resolved photoelectron spectra are recorded with picosecond pulse duration (2+1) REMPI at selected intermediate vibrational excitations. The 3s intermediate state displays a very strong Δv=0 propensity on ionization, but the 3p intermediate evidences more complex vibronic dynamics, and we infer some 3p→3s internal conversion prior to ionization.  相似文献   

14.
Resonance-enhanced multiphoton ionization (REMPI) has been applied to detect the hot bands as well as the cold bands of the 1a2-->-->3dxy(1A1) Rydberg transition of furan (jet-cooled, mass-analyzed). Based on the unambiguous assignment of the hot bands, a complete vibronic analysis is given for the cold bands of this transition (up to 4600 cm(-1) above the origin). This analysis can be used for the interpretation of the vibrational structure in the X 2A2 photoelectron band. The energy ordering of the five 3d Rydberg states is 1A2 approximately 2A2相似文献   

15.
The allyl radical was produced in molecular beam by pyrolysis of allyl iodide. The vi-bronic spectra from ground state to six new electronic states of the allyl radical at 6-8 eV, π→3dxz, π→3dxy, and π→ns (n=4, 6, 7, 8) were observed firstly with the aid of time-of-flight mass spectros-copy and resonance-enhanced multiphoton ionization technique. Vibrational progression of v7 (C3 bend) with gross spacing of about 430 cm-1 was observed in ns Rydberg states. The adiabatic ionization potential of the allyl radical was obtained to be (65641 ± 20) cm-1 ((8.138± 0.002) eV) by fitting the term values of ns (n=4,6,7,8) Rydberg states with Rydberg formula.  相似文献   

16.
In this resonantly enhanced multiphoton ionization (REMPI) experiment, an extended vibrational progression in the CI stretching mode (v3) of methyl iodide (-h3 and -d3) is observed in the 1 + 1′ excitation of the [1/2] 6s; 0 Rydberg state when the pump photon wavelength lies in the bound → free absorption continuum. This is in contrast with one-colour coherent (non-resonant) two-photon excitation, where the v3 mode is not excited. By working at several different fixed probe wavelengths and scanning the pump frequency, the relative contributions from the three intermediate repulsive states can be explored through changes in the relative strengths of the Ω = 0 and 1 components of the final Rydberg states. Extensive predissociation in the Rydberg states curtails the vibrational progression.  相似文献   

17.
We have studied 3s(n-1 and pi-1) Rydberg states and D0(n-1) and D1(pi-1) cationic states of pyrazine [1,4-diazabenzene] by picosecond (2 + 1) resonance-enhanced multiphoton ionization (REMPI), (2 + 1) REMPI photoelectron imaging, He(I) ultraviolet photoelectron spectroscopy (UPS), and vacuum ultraviolet pulsed field ionization photoelectron spectroscopy (VUV-PFI-PE). The new He(I) photoelectron spectrum of pyrazine in a supersonic jet revealed a considerably finer vibrational structure than a previous photoelectron spectrum of pyrazine vapor. We performed Franck-Condon analysis on the observed photoelectron and REMPI spectra in combination with ab initio density functional theory and molecular orbital calculations to determine the equilibrium geometries in the D0 and 3s(n-1) states. The equilibrium geometries were found to differ slightly between the D0 and 3s states, indicating the influence of a Rydberg electron on the molecular structure. The locations of the D1-D0 and 3s(pi-1)-3s(n-1) conical intersections were estimated. From the line width in the D1 <-- S0 spectrum, we estimated the lifetime of D1 to be 12 fs for pyrazine and 15 fs for fully deuterated pyrazine. A similar lifetime was estimated for the 3s(pi-1) state of pyrazine by REMPI spectroscopy. The vibrational feature of D1 observed in the VUV-PFI-PE measurement differed dramatically from that in the UPS spectrum, which suggests that the high-n Rydberg (ZEKE) states converging to the D1 vibronic state are short-lived due to electronic autoionization to the D0 continuum.  相似文献   

18.
丁酮分子的共振增强多光子电离解离研究   总被引:3,自引:0,他引:3  
利用可调谐染料激光研究了丁酮分子的共振增强多光子电离解离过程,发现在428~448nm激光波段丁酮分子发生的是经4p和4dRydberg态的(3+1)多光子过程。此外,我们还用“梯开关”模型对丁酮母体离子的解离机理和各碎片来源作了详细的分析,分析认为在丁酮母体离子的解离过程中存在H原子重排与电荷的重新分布现象。  相似文献   

19.
The (2+1) resonance-enhanced multiphoton ionization (REMPI) spectrum of SF has been obtained in the single-photon wavelength region of 307-321 nm. Five vibronic bands were observed and assigned to the two-photon transitions from the ground state to a 2§ Rydberg state. The term value Te, vibrational frequency, and the rotational constant of the 2§ Rydberg state were determined. Another 2P state was observed near 312 nm.  相似文献   

20.
Mass spectra were recorded for one-colour resonance enhanced multiphoton ionization (REMPI) of H(i)Br (i = 79, 81) for the two-photon resonance excitation region 79,040-80,300 cm(-1) to obtain two-dimensional REMPI data. The data were analysed in terms of rotational line positions, intensities, and line-widths. Quantitative analysis of the data relevant to near-resonance interactions between the F(1)Δ(2)(v' = 1) and V(1)Σ(+)(v' = m + 7) states gives interaction strengths, fractional state mixing, and parameters relevant to dissociation of the F state. Qualitative analysis further reveals the nature of state interactions between ion-pair states and the E(1)Σ(+) (v' = 1) and H(1)Σ(+)(v' = 0) Rydberg states in terms of relative strengths and J' dependences. Large variety in line-widths, depending on electronic states and J' quantum numbers, is indicative of number of different predissociation channels. The relationship between line-widths, line-shifts, and signal intensities reveals dissociation mechanisms involving ion-pair to Rydberg state interactions prior to direct or indirect predissociations of Rydberg states. Quantum interference effects are found to be important. Moreover, observed bromine atom (2 + 1) REMPI signals support the importance of Rydberg state predissociation channels. A band system, not previously observed in REMPI, was observed and assigned to the k(3)Π(0)(v' = 0) ←← X transition with band origin 80,038 cm(-1) and rotational parameter B(v('))=7.238 cm(-1).  相似文献   

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