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1.
用跳浓驰豫法测定不同温度下的驰豫时间τ.根据拟定的机理导出了1/τ的函数表达式为1/τ=k[H6R]0/[H3+O]-(6k/ε[H3+O]0)A,获得表观速率常数k及摩尔吸光系数ε,表观活化能为52.82KJ/mol,活化焓为50.34kJ/mol,活化熵在278K~298K范围内为负值,配合物稳定常数lgK'.为13.84。与孤立变量法、比尔法、平衡移动法获得的结果吻合.  相似文献   

2.
用从头计算法在HF/6-31G*基组水平上研究了NH4++NH3→NH3+NH4+,NH4++NH2CH3→NH3+NH3CH3+,NH4++NH(CH3)2→NH3+NH2(CH3)2+以及NH3CH3++NH2CH3→NH2CH3+NH3CH3+等4个体系的质子传递反应的机理.结果表明:(1)上述质子传递反应均具有双阱型的势能面,质子沿N(1)、N(2)连线直接传递;(2)质子受体分子中的甲基对质子传递起促进作用,而质子给体离子中的甲基则阻碍质子的传递。  相似文献   

3.
采用水热法合成了一个钨-钒簇聚物[Cu(en)2]2[V{Cu(en)2(H2O)}2]·3H2O(1, en=乙二胺), 并通过X射线单晶衍射、 元素分析、 傅里叶变换红外光谱、 X射线粉末衍射、 热重分析、 价键计算、 X射线光电子能谱、 电子顺磁共振和磁性分析对其结构和性能进行了表征. 结果表明, 化合物1是以双支撑的四帽Keggin结构 [(VO4){Cu(en)2(H2O)}2]4- 钨-钒簇合物阴离子为基本结构单元, 与4个[Cu(en)2]2+配合物阳离子以共价键和弱键相连接形成二维层状结构, 相邻层又通过氢键连接成三维超分子网络. 研究了化合物1的磁性及光催化降解罗丹明B的活性.  相似文献   

4.
喻昌木  张荣  卢小鸾  杨敏  彭黔荣 《应用化学》2020,37(10):1211-1220
通过溶胶-凝胶法制备的Imm-Fe3+-IL纳米材料具有类过氧化物酶的活性,能够催化过氧化氢(H2O2)快速氧化3,3′,5,5′-四甲基联苯胺(TMB)产生相应的颜色变化。 稳态动力学分析表明,Imm-Fe3+-IL纳米材料遵循典型的Michaelis-Menten模型和乒乓机理。 辣根过氧化物酶(HRP)相比,Imm-Fe3+-IL纳米材料纳米材料具有更强的亲和性。 联合葡萄糖氧化酶建立了H2O2和葡萄糖的比色检测方法。 结果显示:H2O2和葡萄糖的浓度与反应体系的吸光度呈良好的线性关系,H2O2的线性范围为1~200 μmol/L,葡萄糖的线性范围为10~200 μmol/L,最低检出限(LOD)分别为0.35和3.31 μmol/L。  相似文献   

5.
以Na2CO3, (CH3CO2)2Mn·4H2O, Al2O3, Na3PO4·12H2O和CH3COOLi·2H2O为原料, 通过2次高温固相法和一步水热离子交换法得到一系列铝和磷掺杂的LiMn0.97Al0.03O2, LiMnO1.99(PO4)0.01和LiMn0.97Al0.03O2-x(PO4)x(x=0.01, 0.03, 0.05)化合物. 用X射线衍射(XRD)表征了前驱体及交换产物的晶体结构, 用扫描电镜(SEM) 测定了晶体的形貌. 通过X射线光电子能谱(XPS)、傅里叶红外光谱及恒电流充放电测试, 研究了掺杂离子对合成材料结构及电化学性能的影响. 研究结果表明, Al-PO4复合掺杂综合了Al3+掺杂提高材料的电化学反应活性和减低材料的电化学反应阻抗以及PO43-掺杂增大材料的晶胞体积的特点, 提高材料中Li+的扩散能力, 有效地抑制了材料由于Jahn-Teller效应引起的结构畸变, 改性后的LiMnO2正极材料既保持了较高的容量又获得了良好的电化学循环性能.  相似文献   

6.
本文研究了Eu2+离子在MyAlxBOy+3/2(1+x)(M=Ca,Sr,Ba)基质中的发光性质及磷和卤素对发光的影响。 采用以H2和N2混合气体为还原气氛在高温下进行固相反应的方法合成了一系列磷光体。发现,在CaAlxBO2.5+3/2x基质中,当X在0.5~2的范围内时及在SryAl2BO4 6+基质中,当y在2~6的范围时掺入的Eu3+不能被H2还原为Eu2+。其他Eu2+激活的磷光体一般都产生f~d跃迁的宽带发射,发射峰的波长随着基质组成的不同可在400~600nm的区间的变化。  相似文献   

7.
在298.15 K下,利用等温环境溶解反应热量计,测定了离子液体[Cnmim][H2PO4] (n= 3, 4, 5, 6) (1-烷基-3-甲基咪唑磷酸盐)在水中不同浓度的摩尔溶解热(ΔsolHm),根据Pitzer电解质溶液理论计算得到了标准摩尔溶解焓(ΔsolHm0)和Pitzer焓参数:βMX(0)L, βMX(1)L,和CϕL,并计算了表观相对摩尔焓。通过推导讨论,得到了离子液体[Cnmim][H2PO4](n= 3, 4, 5, 6)同系物每摩尔亚甲基对标准摩尔溶解焓的贡献。  相似文献   

8.
基态H2O+分子离子是重要的星际反应中间体.用MRCISD/cc-pVTZ先计算H2O+势能面,然后拟合成多体势能函数.全域势能面能很好地描述基态H2O+的行为.与两条反应通道的实验能变和其构型翻转反应能垒比较,表明计算结果与实验值相符.对计算点完成了力场的多项式拟合,对其振动模式进行了分析  相似文献   

9.
用密度泛函方法B3LYP/6-311++G(d,p)和高级电子相关的偶合簇法CCSD(T)/6-311++G(d,p)研究了气相离子-分子反应B2H3-+CS2B2H3S-+CS的机理.结果表明,B2H3最可能进攻CS2中碳原子形成三元环中间体,随后通过氢迁移和最终消除CS的反应步骤形成硫原子转移产物H3BBS-+CS,反应大量放热且不需要活化能.B2H3直接对CS2中硫原子进攻夺取硫原子的反应方式存在一定能垒阻碍.计算结果有助于深入了解B2H3,B3H-6和B4H7-等缺电子硼氢负离子的反应行为.  相似文献   

10.
在0 到12 mL·L-1 (体积分数φ=0.00%-1.20%) 范围内考察了不同H2S 浓度对25% (质量分数, w)MoO3/Al2O3和5% (w) CoO-25%MoO3/Al2O3催化剂甲烷化性能的影响. 结果表明, 5%CoO-25%MoO3/Al2O3的甲烷化活性随H2S浓度的增加单调上升, 而25%MoO3/Al2O3对H2S浓度并不敏感. 对比这两种催化剂发现, 只有在H2S浓度高于0.40% (φ) 时, 在25%MoO3/Al2O3中添加Co助剂才会有促进作用; H2S浓度低于0.40% (φ)时, Co助剂会抑制25%MoO3/Al2O3催化剂的甲烷化活性. 分别对反应前后的催化剂表征发现, H2S浓度的改变不会对两种催化剂的物理结构产生明显的影响, 而是通过影响催化剂表面的金属硫化物活性位来影响催化剂的甲烷化性能. 耐硫甲烷化反应体系中较高的硫含量下Co助剂才表现出对25%MoO3/Al2O3催化剂的促进作用. 该研究明确了在MoO3/Al2O3催化剂中添加Co助剂的硫化氢浓度范围, 为工业上选择合适的催化剂提供了依据.  相似文献   

11.
The C2H2 + O(3P) and HCCO + O(3P) reactions are investigated using Fourier transform infrared (FTIR) emission spectroscopy. The O(3P) radicals are produced by 193 nm photolysis of an SO2 precursor or microwave discharge in O2. The HCCO radical is either formed in the first step of the C2H2 + O(3P) reaction or by 193 nm photodissociation of ethyl ethynyl ether. Vibrationally excited CO and CO2 products are observed. The microwave discharge experiment [C2H2 + O(3P)] shows a bimodal distribution of the CO(v) product, which is due to the sequential C2H2 + O(3P) and HCCO + O(3P) reactions. The vibrational distribution of CO(v) from the HCCO + O(3P) reaction also shows its own bimodal shape. The vibrational distribution of CO(v) from C2H2 + O(3P) can be characterized by a Boltzmann plot with a vibrational temperature of approximately 2400 +/- 100 K, in agreement with previous results. The CO distribution from the HCCO + O(3P) reaction, when studied under conditions to minimize other processes, shows very little contamination from other reactions, and the distribution can be characterized by a linear combination of Boltzmann plots with two vibrational temperatures: 2320 +/- 40 and 10 300 +/- 600 K. From the experimental results and previous theoretical work, the bimodal CO(v) distribution for the HCCO + O(3P) reaction suggests a sequential dissociation process of the HC(O)CO++ --> CO + HCO; HCO --> H + CO.  相似文献   

12.
SkeletonVibrationsandForceConstantsof[Fe_2Cr(μ_3-O)(glycine)_6(H_2O)_3](NO_3)_7.3H_2OZhangLin-Na,LinZheng-Yan(StateKeyLaboratoryo...  相似文献   

13.
Anharmonic vibrational frequencies and intensities are computed for hydrogen fluoride clusters (HF)n, with n = 3, 4 and mixed clusters of hydrogen fluoride with water (HF)n(H2O)n where n = 1, 2. For the (HF)4(H2O)4 complex, the vibrational spectra are calculated at the harmonic level, and anharmonic effects are estimated. Potential energy surfaces for these systems are obtained at the MP2/TZP level of electronic structure theory. Vibrational states are calculated from the potential surface points using the correlation-corrected vibrational self-consistent field method. The method accounts for the anharmonicities and couplings between all vibrational modes and provides fairly accurate anharmonic vibrational spectra that can be directly compared with experimental results without a need for empirical scaling. For (HF)n, good agreement is found with experimental data. This agreement shows that the M?ller-Plesset (MP2) potential surfaces for these systems are reasonably reliable. The accuracy is best for the stiff intramolecular modes, which indicates the validity of MP2 in describing coupling between intramolecular and intermolecular degrees of freedom. For (HF)n(H2O)n experimental results are unavailable. The computed intramolecular frequencies show a strong dependence on cluster size. Intensity features are predicted for future experiments.  相似文献   

14.
自由基CN、CH、H在燃烧化学、大气化学、天体发光、环境污染等方面占有极为重要的地位,对于这些自由基发光及形成动力学机理的探讨,无疑是重要的.近年来,人们利用亚稳态惰性原子与膨化物碰撞传能,探讨了CN(AB-+X)的化学发光[‘一、发现亚稳态的Ar(‘几,。)原子与H  相似文献   

15.
~(186,188)Re具有优良的核素性质,是放射性治疗药物的首选核素之一~([1]).~(186,188)Re广泛用于有机小分子化合物,单抗(McAb)、单抗片段(Fab)、受体配基和生物小分子肽,以达到靶向治疗的目的~([2-3]).铼的化学性质与锝极其相似,在标记前以~(188)ReO_4~-形式存在,在标记药物中呈低价态.制备时常规方法是将七价铼通过亚锡法还原到五价~([4-5]).  相似文献   

16.
The infrared spectra of CH3Cl + H2O isolated in solid neon at low temperature have been investigated. High concentration studies of water (0.01%-4%) and subsequent annealing lead to the formation of the ternary CH3Cl:(H2O)2 complex. Detailed vibrational assignments were made on the observed spectra of water and deuterated water engaged in the complex. In parallel, structural, energetic, and vibrational properties of the complex have been studied at the second-order M?ller-Plesset perturbation theory using several basis sets. Anaharmonic correction to the vibrational frequencies has been done with the standard second-order perturbation approach. It was shown that the ground state of the complex has a cyclic form for which the nonadditive three-body contribution was found to be around 10% of the interaction energy.  相似文献   

17.
首次合成了稀土元素镱的异硫氰酸、硝酸复合阴离子穴醚(2,2,2)配合物H2Yb(NCS)~3(NO3)~2.H2O.(2,2,2)。测定了它的晶体结构及红外光谱, 发现Yb^3+没有进入穴醚空穴, 它通过H2O桥以氢键与穴醚的O原子结合。经研究认为, 分子中2个H^+结合在穴醚中2个N原子上。与Yb^3+配位的异硫氰酸根、硝酸根及分子形成八配位的三角十二面几何构型。晶体属单斜晶系, 空间群:P2~1/n。  相似文献   

18.
The C(2)H + O((3)P) --> CH(A) + CO reaction is investigated using Fourier transform visible emission spectroscopy. The O((3)P) and C(2)H radicals are produced by simultaneous 193 nm photolysis of SO(2) and C(2)H(2) precursors, respectively. The nascent vibrational and rotational distributions of the CH(A) product are obtained under time-resolved, but quasi-steady-state, conditions facilitated by the short lifetime of the CH(A) emission. The vibrational temperature of the CH(A) product is found to be appreciably hotter (2800 +/- 100 K) than the rotational distributions in the v' = 0 (1400 +/- 100 K) and v' = 1 (1250 +/- 250 K) levels. The results suggest that the reaction may proceed through an electronically excited HCCO() intermediate; moreover, the vibrational excitation compared to rotational excitation is higher than expected based on a statistical distribution of energy and may be the result of geometrical changes in the transition state. The CH(A) emission is also observed in a C(2)H(2)/O/H reaction mixture using a microwave discharge apparatus to form O atoms, with subsequent H atom production. The nascent rotational and vibrational distributions of the CH(A) determined by the microwave discharge apparatus are very similar to the CH(A) distributions obtained in the photodissociation experiment. The results support the idea that the C(2)H + O((3)P) reaction may play a role in low-pressure C(2)H(2)/O/H flames, as previously concluded.  相似文献   

19.
H_(3+n)[AsMo_(12-n)V_nO_(40)]·9H_2O(n=2—4)的结构   总被引:3,自引:1,他引:3  
邓谦  黄幼青 《结构化学》1993,12(6):430-436
X光晶体结构分析证实H_(3+n)[AsMo_(12-n)V_+nO_(40)]·9H_2)(n=2—4)的晶体同构,空间群为P,Z=2。n=2时,a=13.951(5),b=14.137(5),c=13.556(4),α=112.44(2),β=109.49(3),γ=60.77(3)°,V=2120.2,M_r=1943.36,D_c=3.044g.cm~(-3),μ=40.90cm~(-1),F(000)=1828。用6216个I>3σ(I)的独立衍射精修结构,R=0.082;n=3时,a=13.891(7),b=14.076(5),c=13.483(5)A,α=112.34(3),α=109.26(3),γ=60.82(3)°,V=2094.5,M_r=1899.37,D_c=3.011g.cm~(-3),μ=40.63cm~(-1),F(000)=1792。用6699个I>3σ(I)的独立衍射精修结构,R=0.054;n=4时,a=13.854(3),b=14.099(2),c=13.501(4),α=112.09(2),β=109.13(2),γ=61.03(2)°,V=2103.0,M_r=1855.38,D_c=2.92(悬浮法),D_c=2.930g.cm~(-3),μ=39.71cm~(-1),F(000)=1756。用7613个I>3σ(I)的独立衍射精修结构,R=0.044。实验采用MoKα辐射,λ=0.71073,T=296K。杂多阴离子均呈准Keggin结构,12个金属原子呈无序分布,可以M(Mo/V)表示。AsO_4四面体中As—O键长1.66—1.68,O—As—O键角均在109.5°左右。畸变的MO_6八面体中,M—O键长分布在1.63—2.36范围。水分子无序处在晶胞中十四个位置上,除O_w(12)和O_w(13)外的水分子均与杂多阴离子形成氢键,且水分子间形成如沸石中那样的复杂?  相似文献   

20.
One novel polyoxometalate compound connected via trivalent cerium cation as bridge H2{[K(H2O)2]2[Ce(H2O)5]2(H2Mo1.16W10.84O42)}·8H2O 1 was designed and synthesized in aqueous solution. X-ray diffraction analysis reveals that the structure of 1 is a three-dimensional framework assembled from the arrangement of H2Mo1.16W10.84O42 (named paradodecmetalate-B) and Ce(H2O)53+ containing two planes, which are constructed through the unification of H2Mo1.16W10.84O4210- and Ce(H2O)53+ along the [100] and [001] directions. Crystal data: H96Ce4K4Mo2.32O128W21.68, Mr = 7074.89, monoclinic, P21/n, a = 12.5037(17), b = 17.002(2), c = 12.7473(17) A, β = 105.966(2)°, V = 2605.4(6) 3, Z = 1, Dc = 4.509 g/cm3, F(000) = 3132, μ = 26.098 mm-1, R = 0.0377 and wR = 0.0789 (I > 2σ(I)).  相似文献   

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