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Lin Li Tony Stüker Prof. em. Dr. Lester Andrews Dr. habil. Helmut Beckers Prof. Dr. Sebastian Riedel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(7):1795-1805
Uranium and thorium hydrides are known as functional groups for ligand stabilized complexes and as isolated molecules under matrix isolation conditions. Here, the new molecular products of the reactions of laser-ablated U and Th atoms with HCl and with HBr, namely HUCl, HUBr and HThCl, HThBr, based on their mid and far infrared spectra in solid argon, are reported. The assignment of these species is based on the close agreement between observed and calculated vibrational frequencies. The H−U and U−35Cl stretching modes of HUCl were observed at 1404.6 and 323.8 cm−1, respectively. Using DCl instead to form DUCl gives absorption bands at 1003.1 and 314.7 cm−1. The corresponding bands of HThCl are 1483.8 (H−Th) and 1058.0 (D −Th), as well as 340.3 and 335.8 cm−1 (Th−35Cl), respectively. HUBr is observed at 1410.6 cm−1 and the BP86 computed shift from HUCl is 6.2 cm−1 in excellent agreement. The U−H stretching frequency increases from 1383.1 (HUF), 1404.6 (HUCl), 1410.6 (HUBr) to 1423.6 cm−1 (UH) as less electronic charge is removed from the U−H bond by the less electronegative substituent. These U−H stretching frequencies follow the Mayer bond orders calculated for the three HUX molecules. A similar trend is found for the Th counterparts. Additional absorptions are assigned to the H2AnX2 molecules (An=U, Th, X=Cl, Br) formed by the exothermic reaction of a second HX molecule with the above primary products. 相似文献
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Cadmium atoms from laser ablation react with cyanogen, NC=CN, in excess argon during co-deposition at 4 K, and even more on UV irradiation of the cold samples. Final annealing to 35 K increases bands at 2187.3 and 2089.2 cm−1 at the expense of weaker bands at 2194.6 and 2092.2 cm−1 through addition of another cadmium atom. Reaction products were identified by comparison with B3LYP and CCSD(T) computed frequencies and energies, through frequency differences between Zn and Cd products, and by cyanogen isotopic substitution. The CN radical, ZnNC, and CdNC were observed on sample deposition. Hg arc ultraviolet (UV) irradiation activates the insertion of Cd and Zn to form the NCCdCN, CNCdNC, NCZnCN and CNZnNC molecules. Next annealing increased the dimetal products NCCdCdCN, CNCdCdNC, NCZnZnCN, and CNZnZnNC at the expense of their single metal analogs. Laser ablated mercury amalgam also produced NCHgCN, NCHg−HgCN, CNHgNC and CNHg−HgNC. The Group12 metals form both cyanide and isocyanide products, and the argon matrix also traps the higher energy but much more intensely absorbing isocyanides. In the isocyanide case bond polarity results in very intense infrared absorptions. Group 12 metals produce shorter M−M bonds in the dimetal cyanides NCM−MCN and isocyanides CNM−MNC than in the M−M itself, and their computed M−M bond lengths compare favorably with those measured for dimetal complexes stabilized by large ring containing molecular ligands. 相似文献
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某些离解能、电子亲合能等的G2计算与评价 总被引:1,自引:1,他引:1
PoPle及其合作者创立的Gaussian再简称GZ)理论[‘-’],以其相对可靠的化学精度和相应较小的计算量已经引起了实验和理论化学家们的广泛关注问.p。ple等人在他们的GZ文章中强调了GZ的理论计算结果在研究离解能等化学问题中与精确实验数据之间的偏差普遍不大于全8.狄J规厂‘.我们近期的研究表明*’1,*2和优(*则在计算一般化学反应能量中,绝大多数情况下,分别都能保证结果与实验偏差在全8.4和士13kJ·mol‘以内.近年来,已有大量的研究工作表明,GZ的理论结果已广泛用于未知实验数据的预测、已有实验数据的评价和修正等… 相似文献
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V. V. Ivanovskaya A. N. Enyashin A. L. Ivanovskii 《Journal of Structural Chemistry》2004,45(1):151-155
Quantum-chemical modeling of electronic structure and interatomic interaction parameters has been performed for a series of fullerenelike cage molecules based on the isoelectronic TiO2, SnO2, and SnS2. The above characteristics are analyzed in relation to the type of atomic configuration, as well as the size and chemical composition of a nanostructure. 相似文献
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
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Seong-Ho Choi Jae-Wan Seo Sang-Il Nam Mu-Sang Lee Kwang-Pill Lee 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(4):279-283
FT-Raman spectra of 2-, 3-, and 4-chlorostyrene included in-cyclodextrin (CD),glycerol ether -CD, -CD,sulfated -CD, andglycerol ether -CD were recorded.In the inclusion complexes, the area of the vinyl(C=C) band decreased remarkably, whereasthe area of the phenyl (C=C) band increasedcompared to those of liquid 2-, 3-, and 4-chlorostyrene,respectively. From the results, the inclusion structures of2-, 3-, and 4-chlorostyrene were discussed. 相似文献
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James R. Durig Gamil A. Guirgis J. F. Sullivan T. J. Dickson D. T. Durig 《Structural chemistry》2001,12(2):149-170
The Raman (3500–40 cm–1) and infrared (3500–70 cm–1) spectra of gaseous and solid 2-methoxypropene, CH3O(CH3)C=CH2, and the isotopomers, CD3O(CH3)C=CH2 and CH3O(CD3)C=CD2 have been recorded. In addition, the Raman spectra of the liquids have been recorded with qualitative depolarization measurements. All of these data indicate that only one conformer is present in the fluid phases at ambient temperature and this form is the cis conformer, which remains in the solid. Assignments are provided for the fundamentals of all three isotopomers for the cis conformer with Cs symmetry. The far-infrared spectra of all three isotopic species have been recorded at a resolution of 0.1 cm–1 in the gas and 1.0 cm–1 in the solid. The parameters of the potential function governing the asymmetric torsion are determined to be V3 = 1485 ± 9 cm–1 and V6 = –55 ± 4 cm–1 for the d0 compound, where only two terms were determined, since a second conformer was not evident. The barrier to internal rotation for the methyl group attached to the oxygen atom is 1370 ± 8 cm–1 and the C—CH3 barrier is 772 ± 5 cm–1. Ab initio calculations with full electron correlation have been carried out by the perturbation method to second order to obtain the equilibrium structural parameters, harmonic force constants, fundamental frequencies, infrared intensities, Raman activities, depolarization values, and conformational stability. The predicted values have been compared to the experimental values where appropriate. 相似文献
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《Chemical physics letters》1987,134(4):366-370
After determining reliable procedures for calculating the ionization energy of H2S using many-body perturbation theory and electron propagator theory, the same procedures are used to calculate the vertical ionization energy of the van der Waals molecule (H2S)2. The adiabatic ionization energy calculated for a dimer cation with a H3S+...SH structure is in satisfactory agreement with photoionization threshold experiments. An alternative dimer cation structure with a three-electron S-S bond is also discussed. 相似文献
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
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A potential energy surface has been calculated for the competing associative and reactive ion-molecule processes involving the reactants C3H(+) + H2. Our ab initio results show that the linear ion C3H+ and H2 can directly access the deep potential well of the propargyl ion H2CCCH+, which is calculated to lie 390 kJ mol-1 below the zero-point energy of the reactants. Isomerization between the propargyl ion and the lower energy, cyclic C3H3+ ion, calculated to lie 501 kJ mol-1 below the zero-point energy of reactants, can subsequently occur via two pathways. One of these pathways involves a transition state lying 22 kJ mol-1 below the energy of the reactants while the other, which occurs at much lower energies, involves two transition states and an intermediate. The dissociation of c-C3H3+ into c-C3H2(+) + H is calculated to occur directly, without any intermediate potential energy maximum, but the energy of the products lies 7.3 kJ mol-1 above the energy of the reactants. Using the minimum energy potential pathway and properties of the stationary point structures determined via ab initio methods, we have calculated both the association rate coefficient to produce C3H3+ as a function of density and the branching ratio between the propargyl and cyclic structures of the ion. Our results are in good agreement with some experimental results and in conflict with others. Specifically, we agree with the 1:1 branching ratio measured for the propargyl and cyclic isomers of C3H3+ at 80 and 300 K and we agree with the rate coefficient for radiative association measured at 80 K. We cannot reproduce reported measurements that the reactive channel (C3H2(+) + H) is the dominant channel at 80 K and at low gas densities, or that the association channel at high densities saturates at an effective rate coefficient well below the Langevin value -2x10(-11) cm3 s-1 at 300K and 1x10(-10) cm3 s-1 at 80K. 相似文献
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C120O2的分子结构和光谱性质的理论研究 总被引:1,自引:0,他引:1
用INDO系列方法研究双笼氧化物C120O2分子可能异构体的结构,两个氧以桥键形式分别加成到两个碳笼上,在两个碳笼中间形成呋喃型五元环结构,有6/6连接和6/5连接两种C2v构型.计算表明,C120O2两种构型中6/6连接的C2v构型更稳定,其光谱与实验值相符.双笼氧化物C120O2的形成既缓解了C60O环氧处的角张力,又比C120O分子获得了更强的笼间相互作用,两个C60靠两个呋喃型五元环连接在一起.两个碳笼的多位置直接键连使两碳笼距离较近,有较强的相互作用,但仍各自表现出一定的独立性.C120O2可发生分解生成新的化合物. 相似文献
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Dr. Hongmin Li Dr. Yetsedaw A. Tsegaw Prof. em. Dr. Dr. Lester Andrews Prof. em. Dr. Carl Trindle Prof. Dr. Han-Gook Cho Dr. Tony Stüker Dr. Helmut Beckers Prof. Dr. Sebastian Riedel 《Chemphyschem》2021,22(18):1914-1934
Zinc and cadmium atoms from laser ablation of the metals and mercury atoms ablated from a dental amalgam target react with HCN in excess argon during deposition at 5 K to form the MCN and MNC molecules and CN radicals. UV irradiation decreases the higher energy ZnNC isomer in favor of the lower energy ZnCN product. Cadmium and mercury atoms produce analogous MCN primary molecules. Laser ablation of metals also produces plume radiation which initiates H-atom detachment from HCN. The freed H atom can add to CN radical to produce the HNC isomer. The argon matrix also traps the higher energy but more intensely absorbing isocyanide molecules. Further reactions with H atoms generate HMCN and HMNC hydrides, which can be observed by virtue of their C−N stretches and intense M−H stretches. Computational modeling of IR spectra and relative energies guides the identification of reaction products by providing generally reliable frequency differences within the Zn, Cd and Hg family of products, and estimating isotopic shifts using to 13C and 15N isotopic substitution for comparison with experimental data. 相似文献
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C59O的结构、电子光谱及NMR谱的理论预测 总被引:2,自引:0,他引:2
用INDO系列方法对C60的取代产物C59O进行几何构型优化,得到Cs对称性的稳定构型,以此构型为基础,计算并预测了C59O的电子光谱和NMR谱.最后与C59O的等电子分子体C602-及C60O进行了比较. 相似文献