共查询到18条相似文献,搜索用时 93 毫秒
1.
在355和532nm激光波长下用TOF质谱仪研究了C4H5N-(NH3)n系列氢键团簇体系的多光子电离.实验发现,两波长下除了得到一系列团簇离子外,还观测到一系列质子化产物C4H5N-(NH3)n-H+.这些质子化产物来自于光电离过程中团簇内部的质子转移反应;系列离子出现反常强度变化,即离子强度较离子明显减小;从头计算结果表明,上述现象是由于中性团簇稳定性的差异造成的. 相似文献
2.
在355、532nm激光波长下用TOF质谱研究了C4H5N-(H2O)n氢键团簇体系的多光子电离。二波长下均得到一系列C4H5N-(H2O)n+及质子化产物C4H5N-(H2O)nH+。355nm下可能存在双光子共振电离过程,使得该波长下吡咯母体及团簇离子信号较532nm有明显增强。从头计算结果表明质子化产物的质子更可能连接于吡咯环的α-C原子,而不是N原子上,即光电离过程诱发了一个簇内的质子转移反应。在532nm下质子化产物的生成主要来自于一个发生于团簇内部的Penning电离或电荷转移过程。团簇的形成对吡咯光解产物的稳定化作用使得团簇系列C4H4N-(H2O)n+出现反常强度变化。 相似文献
3.
用355 nm激光对脉冲分子束超声膨胀冷却的甲醇分子进行多光子电离, 飞行时间质谱仪观测到除甲醇碎片离子外的质子化甲醇团簇(CH3OH)nH+(n=1-16), 且离子的种类及相对强度与激光相对于脉冲分子束的延时无关, 取决于团簇离子内在结构的稳定性. 结合从头算密度泛函理论, 在B3LYP/6-31G(d)基组水平上优化得到了(CH3OH)n和(CH3OH)nH+(n=1-4)的稳定构型. 振动频谱分析显示, 团簇中最强的红外振动模主要来自氢键H伸缩振动的贡献. 团簇电离后发生于团簇内的质子转移反应也可能与激光电离引起的与氢键有关的振动模激发密切相关. 相似文献
4.
用355nm激光多光子电离解离飞行时间质谱观测到在超声分子束中形成的最多为12个分子的团簇离子及其碎片.用密度泛函方法对n=2~5的丙酮团簇结构进行计算,给出了优化构型及其基态能量.结果表明,两个丙酮分子组成团簇时稳定结构为近似垂直构型.3~5个丙酮分子组成团簇时以环状结构最稳定. 相似文献
5.
用从头计算法研究了 (N2 H4-CH3OH)氢键团簇体系。分别在HF/6 31G 和HF/6 31G 水平上对它们的中性和离子团簇进行几何全优化 ,得到了 3种中性混合团簇稳定构型和离子混合团簇稳定构型 ,并对其能量和稳定性进行了比较。讨论了 3种不同构型离子团簇可能的解离通道。给出了质子化混合团簇的稳定构型 ,并对其可能的解离通道进行了讨论。文中最后计算出N2 H4,CH3OH ,(N2 H4-CH3OH)团簇的质子亲和能 (PA) ,分别为 :2 0 6.7kcal/mol,1 78.3kcal/mol,2 2 7.5kcal/mol,其中质子亲和能PAcalc[N2 H4]与实验值PAexp[N2 H4]=2 0 4 .8kcal/mol符合得很好。 相似文献
6.
介绍了一种通过计算分子的同位素丰度模拟质谱峰型,根据比较质谱峰的位置和形状来帮助归属多元素团簇的飞行时间质谱的方法。这种方法不仅有助于归属完全分辨的低质量离子峰,还能从重叠的质谱峰中确定各个组份的相对含量。 相似文献
7.
对H2O,NH3单分子以及反式线性NH3…H2O双分子团簇应用HF,DFT,MR2,CCD ,QCISD等从头计算方法在不同的基组水平上进行几何结构优化和氨—水分子间相 互作用能计算。比较实验值和计算结果表明:对氨—水体系,MP2/6-31+G^**方法 能够满足氢键N-0键长误差为0.004nm,键角∠NOH误差为1°,NH3…H2O相互作用 能△E与CCD和QCISD偏差2.1kJ/mol计算精度的要求,并有较合理的计算代价。 相似文献
9.
用激光溅射-分子束技术研究了气相中Cu的等离子体与乙醇分子团簇的反应.观察到三种团簇正离子Cu+(C2H5OH)n、CuO+(C2H5OH)n、H+(C2H5OH)n和三种团簇负离子(C2H5OH)nC2H5O-、(C2H5OH)n(H2O)OH-、(C2H5OH)n(H2O)2OH-(n≤12).详细考察了在不同的载气压力下激光烧蚀等离子体作用于脉冲分子束, 以及在一定的压力下等离子体作用于分子束不同位置时,对团簇产物种类和团簇尺寸大小的影响.分析了Cu+(C2H5OH)n、CuO+(C2H5OH)n、H+(C2H5OH)n、(C2H5OH)nC2H5O-、(C2H5OH)n(H2O)OH-、(C2H5OH)n(H2O)2OH-等团簇的产生机理. 相似文献
10.
The one-color resonant two -photon ionization technique is employed to study jetcooled van der Waals(vdW) complex o-xylene?N2 through the S0-S1 transition around the band. The spectra obtained exhibit rich information about the complex intermolecular vdW vibrational modes. We have tentatively assigned all the observed spectral features. The structure of the complex has been obtained by calculation of the minimum energy structure. 相似文献
11.
Multiphoton ionization and the subsequent dissociation process of metal cluster complexes Os 3(CO) 12 and Ir 4(CO) 12, prepared in a supersonic jet, were studied by means of multiphoton ionization with time-of-flight (TOF) mass detection. The ionization energies of Os 3(CO) 12 and Ir 4(CO) 12 were determined to be 7.95 and 8.3 eV, respectively, from the laser wavelength at the ionization threshold. The coordination energies of Os 3(CO) 12+ and Ir 4(CO) 12+ ions were also determined to be 1.6 and 1.2 eV, respectively, from the excitation energy needed to cause the appearance of fragment ions. The observed values agreed reasonably well with the ones calculated by using the density functional theory method. 相似文献
12.
1-Allyl-4-aminopyridinium chloride reacts with Cu(NO 3) 2 · 3H 2O in an ethanolic solution under the conditions of ac electrochemical synthesis at copper electrodes to form crystals of compound
[(NH 2C 5H 4N(C 3H 5)) 2Cu 3Cl 3(NO 3) 2] ( I). The crystals of compound I are monoclinic: space group P2 1/ c, Z = 4, a = 25.770(7), b = 7.230(4), c = 12.505(5) ?, β = 92.58(3)°, V = 2328(2) ? 3. The direct interaction of 1-allylquinolinium nitrate with Cu(NO 3) 2 · 3H 2O in a methanolic solution in the presence of metallic copper yields crystals of compound [C 9H 7N(C 3H 5)Cu(NO 3) 2] ( II). The crystals of compound II are triclinic: space group P
, a = 6.756(3), b = 8.391(4), c = 12.489(5) ?, α = 77.18(3)°, β = 89.48(4)°, γ = 73.32(3)°, V = 662.0(5) ? 3. The structure of compound I is built of infinite linear anions: polymeric fragments {(NH 2C 5H 4N(C 3H 5)) 2Cu 3Cl 3(NO 3) 2}
n
. Each of two copper atoms (Cu(1) and Cu(2)) π-coordinates the C=C bonds of the allyl groups of the 1-allyl-4-aminopyridinium
cations, the oxygen atom of the nitrate ions, and two chlorine atoms. The third copper atom Cu(3) is linearly linked with
two chlorine atoms. Particular polymeric fragments are additionally joined by the N-H…O, C-H…O, C-H…Cl hydrogen bonds. The
crystal structure of compound II is built-up of the isolated L 2Cu 2(NO 3) 4 fragments (L is the 1-allylquinolinium cation). The metal atom is localized in the trigonal pyramidal coordination environment
of three oxygen atoms of the nitrate ions and of the C=C bond of the allyl group of the cation. The particular L 2Cu 2(NO 3) 4 fragments are additionally joined by the C-H…O hydrogen bonds.
Original Russian Text ? A.V. Pavlyuk, T. Lis, M.G. Mys’kiv, 2009, published in Koordinatsionnaya Khimiya, 2009, Vol. 35, No.
6, pp. 458–462. 相似文献
13.
[Cp 4Fe 4(CO) 4] ( 1) reacts with p-BrC 6H 4Li and MeOH in sequence to afford the functionalized cluster [Cp 3Fe 4(CO) 4(C 5H 4- p-C 6H 4Br)] ( 2), while the reaction of 2 with n-BuLi and MeOH produces [Cp 2Fe 4(CO) 4(C 5H 4Bu)(C 5H 4- p-C 6H 4Br)] ( 3). The double cluster [Cp 3Fe 4(CO) 4(C 5H 4)] 2( p-C 6H 4) ( 4) has been prepared by treatment of [Cp 4Fe 4(CO) 4] with p-C 6H 4Li 2 and MeOH in sequence. The electrochemistry of 2 and 4, as well as the crystal structure of 4 have been investigated. 相似文献
14.
LnCl 3 (Ln=Nd, Gd) reacts with C 5H 9C 5H 4Na (or K 2C 8H 8) in THF (C 5H 9C 5H 4 = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C 5H 9C 5H 4)LnCl 2(THF) n (orC 8H 8)LnCl 2(THF) n], which further reacts with K 2C 8H 8 (or C 5H 9C 5H 4Na) in THF to form the litle complexes. If Ln=Nd the complex (C 8H 8)Nd(C 5H 9C 5H 4)(THF) 2 (a) was obtained: when Ln=Gd the 1 : 1 complex [(C 8H 8)Gd(C %H 9)(THF)][(C 8H 8)Gd(C 5H 9H 4)(THF) 2] (b) was obtained in crystalline form. The crystal structure analysis shows that in (C8H8)Ln(C5H9C5H4)(THF)2 (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η5), cyclooctatetraenyl (η8) and two oxygen atoms from THF are coordinated to Nd3+ (or Gd3+) with coordination number 10. The centroid of the cyclopentadienyl ring (Cp′) in C5H9C5H4 group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd3+ (or Gd3+). In (C8H8)Gd(C5H9C5H4)(THF), the cyclopentyl-cyclopentadienyl (η5), cyclooctatetraenyl (η8) and one oxygen atom are coordinated to Gd3+ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd3+, which is almost in the plane (dev. -0.0144 Å). 相似文献
15.
IR and Raman spectra of gaseous and solid CpGeX 3 species (Cp C 5H 5 and X = Cl, Br, I) are reported. The results are compared with those obtained previously for CpTiCl 3. Internal rotation barriers and thermodynamic functions are reported. 相似文献
16.
A novel nickel(Ⅱ) complex with 2,4-dihydroxybenzalidene benzoylhydrazone and pyridine ligands, Ni(C 14H 10N 2O 3)(C 5H 5N), has been synthesized and characterized by elemental analysis and IR. The crystal structure of the title complex has been determined by single crystal X-ray diffraction techniques. The crystal belongs to orthorhombic, space group Pbca. The cell parameters are: a=1.580 20(19) nm, b=1.362 18(16) nm, c=1.616 50(19) nm, and V=3.479 5(7) nm 3, Z=8, Dc=1.497 Mg·m -3, μ(Mo Kα)=1.139 mm -1, F(000)=1 616, R=0.032 9 and wR=0.077 0 for 2 772 observed reflections ( I>2 σ(I)) out of 3810 unique ones. The nickel(Ⅱ) ion lies in a distorted square-planar environment composed of two oxygen atoms, one nitrogen atom of tridentate acyhydrazone schiff base ligand and one nitrogen atom of the pyridine ligand. The analysis of the crystal structure indicates that the complex has a one-dimensional chain structure, which is formed by intermolecular hydrogen bonds. CCDC: 244668. 相似文献
17.
The title coordination compound with N-substituted-salicyl Schiff ligand, Cu(C 15H 12N 2O 3)(C 5H 5N), has been synthesized. The coordination compound crystallizes in orthorhombic system, space group Pbca with a=2.037 62(7) nm, b=0.698 45(2)nm, c=2.508 76(9)nm, V=3.570 4(2) nm 3, Z=8, F(000)=1 688, Dc=1.529 g·cm -3, Mr=410.91, μ=1.250 mm -1, R=0.031 3 and wR=0.077 0. In the coordination compound, one phenolate oxygen, one carbonyl oxygen and one hydrazine nitrogen atom from the dianionic ligand N-salicylaldehyde- N′-(4-methoxybenzoyl) hydrazone and one pyridine nitrogen atom coordinate to Cu(Ⅱ) ion, forming a distorted square plane. CCDC: 218182. 相似文献
18.
Ohne Zusammenfassung 相似文献
|