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The unimolecular dissociation reactions of doubly charged ions were reported,which resulted from a tandem mass spectrometer and a reversed geometry double focusing mass spectrometer by electron impact.Mass analyzed ion kinetic energy spectrometry(MIKES) was used to obtain the kinetic energy releases in charge separation reactions of doubly charged ions.The intercharge distances between the two charges at transition states can be calculated from the kinetic energy releases.Transition structures of unimolecular dissociation reactions were infered from MIKES and MS/MS. 相似文献
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用一束波长为230.1nm的激光,通过(2 1)共振增强多光子电离(REMPI)过程激发超声射流冷却的CO分子制备处于基电子态X2Σ 的CO ,随后引入另一束可调谐激光将CO 离子激发至A2Π1/2,3/2态,利用光电倍增管(PMT)检测发射的荧光信号强度随激发光波长的变化,分别在487-493nm和453-459nm波长范围内获得了CO 离子A2Π1/2,3/2←X2Σ 电子态跃迁(0,0)和(1,0)带的激光诱导荧光(LIF)激发谱. 相似文献
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MA Dong |sheng Gao Shan + {** } HUO Li |hua GAO Jing |sheng College of Chemistry Chemical Engineering Heilongjiang University Harbin P. R. China 《高等学校化学研究》2004,20(3):341-344
IntroductionAsthevanadate dependentenzyme ,ahaloperox idase,andvanadiumnitrogenasehavebeenfoundinsuccession ,somescientistsareinterestedinthecoor dinationchemistryandthebiochemistryofvanadi um[1] .Thereactivecenterofvanadiumbromoperoxi dasecontainstheoxovanadiumVO3+ coordinatedbyoxygenandnitrogenatoms[2 ] .However,thestudiesaboutoxovanadiumVO3+ coordinationcompoundscontainingbioactiveligandsarerarelyfound[3— 8] .Hydroximicacidthatcanbeconsideredtobethederivativeofthecarboxylicacid ,theamide… 相似文献
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用一束波长为230.1 nm的激光, 通过(2+1)共振增强多光子电离(REMPI)过程激发超声射流冷却的CO分子制备处于基电子态X2∑+的CO+离子, 随后引入另一束可调谐激光将CO+离子激发至A2∏1/2,3/2态, 利用光电倍增管(PMT)检测发射的荧光信号强度随激发光波长的变化, 分别在487-493 nm和453-459 nm波长范围内获得了CO+离子A2∏1/2,3/2←X2∑+电子态跃迁(0,0)和(1,0)带的激光诱导荧光(LIF)激发谱. 相似文献
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A. V. Gerasimenko A. V. Polishchuk L. M. Volkova E. T. Karaseva V. E. Karasev 《Russian Journal of Coordination Chemistry》2008,34(1):8-13
Nalidixium tetrachloroantimonate monohydrate, (C12H13N2O3)SbCl4 · H2O, has been synthesized and its crystal structure has been determined. The structure is built of the [Sb2Cl8]2? anions, C12H13N2O 3 + nalidixium cations, and H2O molecules joint by hydrogen bonds and π-π-and Cl?Cl interactions. The [Sb2Cl8]2? anion is a dimer of the SbCl5 E distorted octahedra sharing common Cl?Cl edge (E is the lone electron pair). The Sb polyhedra contain two short Sb-Cl bonds (2.387 and 2.395 Å), one bond of a medium length (2.508 Å), and two long bridging bonds (2.745 and 3.054 Å). 相似文献
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Powers MD Pregitzer KS Palik BJ 《Journal of the American Society for Mass Spectrometry》2008,19(9):1330-1335
Stable isotope ratios of carbon (delta(13)C) and oxygen (delta(18)O) are increasingly used to investigate environmental influences on plant physiology. Cellulose is often isolated for isotopic studies, but some authors have questioned the value of this process. We studied trends in delta(13)C and delta(18)O of whole foliage and holocellulose from seedlings of three Pinus species across three overstory environments to evaluate the benefits of holocellulose extraction in the context of a traditional ecological experiment. Both tissue types showed increasing delta(13)C from closed-canopy controls to thinned plots to 0.3 ha canopy gaps, and no change in delta(18)O between overstory environments. delta(13)C of P. resinosa and P. strobus was greater than delta(13)C of P. banksiana in whole foliage and holocellulose samples, and there were no differences in delta(18)O associated with species in either tissue type. Our results suggest whole foliage and holocellulose provide similar information about isotopic trends across broad environmental gradients and between species, but holocellulose may be better suited for studying differences in stable isotope composition between multiple species across several treatments. 相似文献
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Under hydrothermal conditions, two new ribbon-like structures, [Cu(C14H9O4)-analysis revealed that these structures were constructed by mixed ligands. The coordination polymer forms the basic architecture while the weak interactions extend the framework into a secondary structure. The whole structures of them are governed by collaboration of the strong and weak interactions. Compound 1 crystallizes in monoclinic, space group C2/c with a = 17.0485(3), b =1 1.0558(3), c = 22.7623(4) A, β = 102.465(1)°, V = 4189.2(2) A3, Z = 4, Mr = 915.44, Dc = 1.451g/mL, F(000) = 1900 andμ(MoKα) = 0.587 cm-1. The final R and wR are 0.0030 and 0.1022,respectively for 3037 observed reflections with I > 2σ(I). Compound 2 crystallizes in monoclinic,space group P21/c with a = 11.5963(4), b = 11.7004(5), c = 17.1254(5) A,β = 95.620(1)°, V =2312.4(1) A3, Z = 4, Mr = 556.35, Dc = 1.598 g/mL, F(000) = 1132 andμ(MoKα) = 0.912 cm-1The final R and wR are 0.0431 and 0.1050, respectively for 2629 observed reflections with I > 2σ(I). 相似文献
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The structure of the syn-isomer of 2-N,N′-dimethylamino-5-methylbenzophenone oxime is studied by X-ray diffraction and mass-spectrometry. This molecular compound crystallizes in the triclinic system. Unit cell parameters are: a = 19.5318(10) Å, c = 19.5439(17) Å, V = 6456.9(7) Å3, Z = 18, space group R $ \bar 3 The structure of the syn-isomer of 2-N,N′-dimethylamino-5-methylbenzophenone oxime is studied by X-ray diffraction and mass-spectrometry. This molecular
compound crystallizes in the triclinic system. Unit cell parameters are: a = 19.5318(10) ?, c = 19.5439(17) ?, V = 6456.9(7) ?3, Z = 18, space group R
. The molecules are linked into centrosymmetric pseudo dimers by hydrogen bonds O-H…N formed by the oxime groups. The pathway
of the electron-impact induced decomposition of the compound is discussed.
Original Russian Text Copyright ? 2008 by O. V. Kulikov, L. Kh. Minacheva, and A. V. Mazepa
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Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 4, pp. 791–794, May–June, 2008. 相似文献
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K. Hohenlohe-Oehringen 《Monatshefte für Chemie / Chemical Monthly》1958,89(6):635-648
Zusammenfassung Die Annahme einer chinolartigen Struktur für das Diazid C16H13N7 (I), dessen Synthese durch Umsatz des -(p-Tolyl)-zimtsäurenitrildibromides (IV) mit Silberazid in der 4. Mitt. über die Benzylumlagerung beschrieben wurde1, wird durch die Ergebnisse verschiedener chemischer und physikalischer Angriffe auf dieses Molekül (I) erhärtet. diese Angriffe führten sämtlich infolge der Aromatisierungstendenz des Diazides (I) zu Umlagerungen, welche nach zwei prinzipiell verschiedenen Richtungen verliefen:Chemische Einwirkungen führten zu einer Eliminierung von HN3 unter Abspaltung der -Azidogruppe und Bildung eines aromatischen Reaktionsproduktes (II) bzw. dessen Folgeprodukten.Bei rein thermischer Behandlung dagegen in verschiedenen Lösungsmitteln aromatisierte sich die Diazidoverbindung (I) durch bloße Isomerisierung zu (III).Der aus der Strukturformel von diazid I zu erwartende ungesättigte desaromatisierte Charakter von I und der aromatisch gesättigte Charakter des zu I isomeren Diazides III wurde durch eine Reihe von Reaktionen unterstrichen. Die Struktur von II bzw. Folgeprodukten wurde durch Zweitsynthesen, die Struktur von III durch Abbau-und Umwandlungsreaktionen sichergestellt. 相似文献
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《Polyhedron》2003,22(14-17):1777-1782
(PPh4)2[Mn12O12(O2CCHCl2)16(H2O)4] (3) has been prepared by the two-electron reduction of [Mn12O12(O2CCHCl2)16(H2O)4] (2) using iodide. Crystallization from CH2Cl2/hexanes yields a mixture of two crystal forms, 3·4CH2Cl2·H2O (3a) and 36CH2Cl2 (3b), which are triclinic and monoclinic, respectively. They are both trapped valence 2Mn(II), 6Mn(III), 4Mn(IV). DC magnetization data for dried, unsolvated 3 in 1.80–4.00 K and 10–70 kG ranges were fit to give S=10, D=−0.28 cm−1, g=2.00. Frequency-dependent out-of-phase (χ″M) signals in AC susceptibility studies on crystalline sample of 3a and 3b combined with DC relaxation decay data were fit to the Arrhenius equation to give an effective energy barrier of Ueff=18.5 and 30.3 K, respectively. Magnetization vs. DC field sweeps on single crystals of 3a and 3b gave hysteresis loops containing steps due to quantum tunneling of magnetization (QTM). The step separations yielded ∣D∣/g values of 0.087 and 0.14 cm−1, and consequently U=20 and 39 K (for g=2) for 3a and 3b, respectively, suggesting that the differences in Ueff are primarily caused by changes to D. This work demonstrates the sensitivity of the magnetic properties of [Mn12]2− single-molecule magnets to subtle differences in their environment. 相似文献
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S. P. Solodovnikov E. G. Gal'pern I. V. Stankevich A. L. Chistyakov 《Russian Chemical Bulletin》1999,48(7):1246-1249
Electronic structure of the C120
·+ radical cation and the paramagnetic C120O2+ dication and C120O2− dianion in the triplet state was calculated by the MNDO/PM3 method in the valence approximation. The density distributions
of the unpaired electrons in these systems were found and the ESR spectra of the above species were interpreted.
Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 7, pp. 1257–1260, July, 1999. 相似文献
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在合成一种新的杂多化合物(K13PV12Cr2O42)的基础上,进一步考察了反应温度、过氧化氢起始浓度,以及该杂多化合物作为催化剂时的用量对过氧化氢分解反应的催化作用;并将其与同结构的杂多化合物K7PV12Mo2O42对该反应的催化作用进行了比较。在30~50℃范围内得到了催化反应的速率常数,并由Arrhenius公式计算出反应的活化能约为70.63kJ·mol-1,表明所合成杂多化合物对H2O2分解具有良好的催化性能,也说明Cr3+对V5+的取代有助于改善杂多化合物的催化性能。推导出了H2O2催化分解反应的速率方程。 相似文献
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采用内脏式CO激光磁共振(LMR)技术测量了~(14)N~(16)O的X~X Zeeman跃迁谱,并对其进行了标识、在Hund情形(a)双原子分子结构模型的基础上,采 用先进的同位素分子参数标度函数,对已发表的~(14)N~mO(m= 16, 17, 18)光谱实验数据及 测量的 LMR光谱数据进行了统一的分析计算,得到~14N~16O分子基态的精确结构参数, 其精度比前人的结果提高了 1- 2个数量级,并由此推导出~(14)N~(17)O及~(14)N~(18)O等同位素分 子的结构参数. 相似文献