Alkalimetallnitrido‐tecto‐metallate(VI) mit Netzwerken von Sechsringen spitzenverknüpfter Tetraeder [(MNN3/2)6] mit M = Mo,W der unerwarteten Zusammensetzung A9+x[M6N15] mit A = Rb,Cs und 0 < x < 1

Alkali Metal Nitrido Tecto Metallates(VI) with Networks of Six‐membered Rings of Corner‐sharing Tetrahedra [(MNN_3/2)₆] with M = Mo, W of the Unexpected Composition A_9+x[M₆N₁₅] with A = Rb, Cs and 0 < x < 1 Reactions of metal powders of Mo and W respectively with amides and azides of Rb and Cs lead to the compounds Rb_9+x[W₆N₁₅] and Cs_9+x[M₆N₁₅] with M = Mo, W and 0 < x < 1. The reactions are carried out at 650 °C in autoclaves for salt melts and are finished within 5 d. Crystals of the compounds are embedded in a matrix of the corresponding alkali metal. These metals result from the thermal decomposition of the amides and azides used in high molar ratios. The metals are washed out by liquid ammonia. Besides microcrystalline material of the above mentioned compounds single crystals suitable in size for x‐ray structure determinations were isolated. The compounds crystallize in the space group R3c (No. 167) with Z = 6 and the following lattice constants: Rb_9+x[W₆N₁₅]: a = 12.743(7) Å, c = 27.794(8) Å, c/a = 2.181 Cs_9+x[Mo₆N₁₅]: a = 13.104(5) Å, c = 28.430(9) Å, c/a = 2.170 Cs_9+x[W₆N₁₅]: a = 13.136(5) Å, c = 28.472(6) Å, c/a = 2.167 The metal centres of tetrahedra [MNN_3/2] are condensated to cyclohexane analogue six‐membered rings in chair‐form via nitrogen atoms and axial ones connect them to a three‐dimensional network. Nine – as to the formula unit – of the alkali metal atoms are located in vacancies of the anionic partial structure. The residual atoms with 0 < x < 1 centre the six‐membered rings and are coordinated planar hexagonal by N neighbours.     

Synthese und Struktur von [(Me2PhP)3Cl2ReN]2ReCl4, [(Me2PhP)3Cl2ReN]2ReCl4 · 2 SbCl3 und [Re(NH)Cl2(PMe2Ph)3][SbCl6]

Synthesis and Structure of [(Me₂PhP)₃Cl₂ReN]₂ReCl₄, [(Me₂PhP)₃Cl₂ReN]₂ReCl₄ · 2 SbCl₃ and [Re(NH)Cl₂(PMe₂Ph)₃][SbCl₆] The reaction of ReNCl₂(PMePh)₃ with SbCl₅ in toluene yields the trinuclear complex [(Me₂PhP)₃Cl₂Re≡N]₂ReCl₄ · 2 SbCl₃ ( 1 · 2 SbCl₃). It forms triclinic crystals with the composition 1 · 2 SbCl₃, as well as monoclinic crystals 1 · 2 SbCl₃ · 4 C₇H₈. The monoclinic crystals with the space group P2₁/c, and a = 1212.3(2), b = 2098.5(4), c = 1827.7(3) pm, β = 95.51(1)°, Z = 2, have been used for a crystal structure determination. In the centrosymmetric complex 1 two complexes ReNCl₂(PMe₂Ph)₃ coordinate with their nitrido ligands a square planar, central unit ReCl₄. The SbCl₃ molecules are coordinated by chlorine bridges to Cl atoms of 1 , and, in addition, connect the complexes 1 with each other. The SbCl₃ free compound 1 is obtained in good yield by the reaction of ReNCl₂(PMePh)₃ with ReCl₄(NCEt)₂. It crystallizes in the triclinic space group P1 with a = 1037.7(3), b = 1153.0(2), c = 1393.8(3) pm, α = 72.31(2)°, β = 74.06(2)°, γ = 67.94(2)°, and Z = 1. The bond lengths of the Re–N triple bonds are 172 pm in 1 and 170 pm in 1 · 2 SbCl₃. By the reaction of ReNCl₂(PMePh)₃ with SbCl₅ in CH₂Cl₂ the solvent is decomposed forming HCl which protonates the nitrido ligand to afford the imido complex [Re(NH)Cl₂(PMe₂Ph)₃][SbCl₆] ( 2 ) crystallizing in the monoclinic space group P2₁/n with a = 1221.4(2), b = 1358.6(2), c = 2177.3(1) pm, β = 92,72(1)° and Z = 4. The Re–N distance in the almost linear unit Re≡N–H is 169,1 pm.     

Halogen‐bridged Cationic Complexes of the Type [{CpM(CO)3}2X]SbF6 (M = Mo,W; X = Cl,I), [{CpW(CO)2Cl2}2Cl]SbCl6, and the Trichloride CpW(CO)2Cl3

The reaction of CpMo(CO)₃X (X = Cl, I) with SbF₅ in toluene leads to the cationic, halogen bridged compounds [{CpMo(CO)₃}₂X]SbF₆ ( 1 , 2 ). CpW(CO)₃Cl reacts with SbF₅ to yield [{CpW(CO)₃}₂Cl]SbF₆ ( 3 ), whereas with SbCl₅, the oxidative substitution product [{CpW(CO)₂Cl₂}₂Cl]SbCl₆ ( 4 ) is formed, which decomposes in solution to yield the trichloride CpW(CO)₂Cl₃ ( 5 ). The strong Lewis acid SbF₅ separates the halide from CpM(CO)₃X (M = Mo, W), and the resulting cationic fragment “CpM(CO)₃⁺” reacts with a further CpM(CO)₃X forming a halonium bridge ( 1 – 3 ). The exclusive formation of SbF₆^– can be explained by the oxidizing power of SbF₅. The IR, MS and NMR spectra of the compounds 1 – 5 as well as the X‐ray structure analysis of 5 are reported and discussed.     

[Re{NB(C6F5)3}(Et2dtc)2]2 – Dimerisierung infolge der Ausbildung einer Nitridobrücke

[Re{NB(C₆F₅)₃}(Et₂dtc)₂]₂ – Dimerization as a Consequence of the Formation of a Nitrido Bridge The title compound is formed from [ReN(Et₂dtc)₂] with five‐coordinate Re atom upon reaction with B(C₆F₅)₃. As a consequence of the formation of a nitrido bridge between Re and B the structural trans influence of the nitrido ligand decreases and its trans position which is not occupied in the edduct becomes available for co‐ordination. The dimer is built up by two [Re{NB(C₆F₅)₃}(Et₂dtc)₂] units which are linked by weak bonds between the metal and each one sulphur atom of the neighbouring unit (Re–S: 2.856(6) and 2.835(6) Å, respectively).     

Synthese und Struktur von dreikernigen Heterometall-Komplexen mit Nitridobrücken zwischen Re und Sn

Synthesis and Structure of Threenuclear Heterometallic Complexes with Nitrido Bridges between Re and Sn The threenuclear heterometallic complex [(Me₂PhP)₂ClRe(μ-Cl)N]₂SnCl₄ results from the reaction of ReNCl₂(PMe₂Ph)₃ with SnCl₄ in CH₂Cl₂. The brown, air-sensitive complex is diamagnetic. It crystallizes with two solvate molecules as [(Me₂PhP)₂ClRe(μ-Cl)N]₂SnCl₄ · 2 CH₂Cl₂ in the space group P 1 with a = 1189.1(2), b = 1262.3(2), c = 1776.7(3) pm, α = 86.04(2), β = 89.27(2), γ = 72.75(1)°, Z = 2. In the threenuclear complex two fragments (Me₂PhP)₂ClReN, which are connected by two Cl bridges, coordinate with their nitrido ligands one SnCl₄ molecule. The two resulting nitrido bridges complete the coordination of the Sn atom to a distorted octahedron with a cis arrangement of the N atoms. The bent nitrido bridges (Re–N–Sn = 155) are asymmetrical with distances Re–N = 168 pm and Sn–N = 225 pm. An incomplete exclusion of water during the synthesis leads to the formation of [(Me₂PhP)₃ClRe(μ-Cl)N]Sn₂(OH)Cl₇ · 2 CH₂Cl₂ in form of air-stable, red-violett crystals (P 1, a = 1074.1(2), b = 1251.1(3), c = 1685.0(1) pm, α = 99.61(2), β = 91.49(2), γ = 92.69(2)°, Z = 2). In the diamagnetic complex one molecule ReNCl₂(PMe₂Ph)₃ is coordinated by the nitrido ligand and one Cl bridge to the Sn atoms of a unit Sn₂(OH)Cl₇. In this unit the two Sn atoms are connected by one Cl and one OH bridge. The distances in the almost linear nitrido bridge (Re–N–Sn = 164.6) are Re–N = 170.5 pm and Sn–N = 219.8 pm.     

桥梁多模态耦合抖振控制方法研究

目前已证实调谐质量阻尼器(TM D)可以有效控制桥梁抖振响应,并已在工程中得到应用。然而,传统桥梁抖振被动控制理论是基于单模态叠加SRSS法,无法考虑多模态参与作用和模态间气动耦合效应,本文基于Scan lan多模态耦合抖振理论和多重调谐质量阻尼器(M TM D)被动控制理论,提出一种桥梁多模态耦合抖振M TM D控制方法,该方法可以考虑多模态参与作用、模态间气动耦合效应和单模态中各模态位移分量的气动耦合,且对各TM D在主梁上的安装位置没有任何限制。本文最后采用时域仿真方法对该方法进行了验证,两者计算结果吻合良好,表明本文所提出的方法的正确性。     

Influence of fluorination of xerogels on the intensity of photoluminescence of gamma-irradiated sol-gel quartz glasses

We investigated the influence of fluorination of xerogel on the intensity of luminescence with a maximum at 1.9 eV attributable to nonbridging oxygen atoms in gamma-quanta irradiated sol-gel quartzglasses. It is established that in samples with a high content of hydroxyl groups (more than 8 ppm) the intensity of this luminescence correlates with the content of hydroxyl in the initial samples. Fluorination of gels at the technological stage before sintering substantially reduces the number of silanol groups, improves the quality of glass, and increases their radiative-optical stability. Translated from Zhurnal Priklandoi Spektroskopii, Vol. 67, No. 2, pp. 266–268, March–April, 2000. This work was carried out with financial support from the Belarusian Republican Foundation for Fundamental Research, project F98-139.     

悬索桥颤振稳定性分析的精细时程积分法

研究精细时程积分法在悬索桥颤振稳定性分析中的应用,首先,将 气流整个作为一个系统,组集系统关于模态广义坐标的状态空间方程,然后,应用精细时程积分法计算状态的向量的时程响应,根据状态向量时程响应的对数衰减率判断系统的颤振稳定性,最后,以英国塞文悬索桥为数值算例,验证了本文方法的正确性。     

液相色谱/电喷雾质谱(LC/ESI/MS)在蛋白质分析鉴定中的应用

对液相色谱／电喷雾质谱（LC／ESI／MS）在蛋白质分子量测定、一级结构的分析、蛋白质和多肽纯度的鉴定、肽质量酶谱、蛋白质分子内二硫键的定量和定位、磷酰化位置的测定以及在蛋白质组中的应用等方面进行了综述和讨论。     

Umsetzungen von Cp*NbCl4 und Cp*TaCl4 mit Trimethylsilyl‐azid,Me3Si‐N3. Molekülstrukturen der bis(azido)‐oxo‐verbrückten Komplexe [Cp*NbCl(N3)(μ‐N3)]2(μ‐O) und [Cp*TaCl2(μ‐N3)]2(μ‐O) (Cp* = Pentamethylcyclopentadienyl)

Reactions of Cp*NbCl₄ and Cp*TaCl₄ with Trimethylsilyl‐azide, Me₃Si‐N₃. Molecular Structures of the Bis(azido)‐Oxo‐Bridged Complexes [Cp*NbCl(N₃)(μ‐N₃)]₂(μ‐O) and [Cp*TaCl₂(μ‐N₃)]₂(μ‐O) (Cp* = Pentamethylcyclopentadienyl) The chloro ligands in Cp*TaCl₄ (1c) can be stepwise substituted for azido ligands by reactions with trimethylsilyl azide, Me₃Si‐N₃ (A) , to generate the complete series of the bis(azido)‐bridged dimers [Cp*TaCl_3‐n(N₃)_n(μ‐N₃)]₂ ( n = 0 (2c) , n = 1 (3c) , n = 2 (4c) and n = 3 (5c) ). If the solvent CH₂Cl₂ contains traces of water, an additional oxo bridge is incorporated to give [Cp*‐TaCl₂(μ‐N₃)]₂(μ‐O) (6c) or [Cp*TaCl(N₃)(μ‐N₃)]₂(μ‐O) (7c) , respectively. Both 6c and 7c are also formed in stoichiometric reactions from [Cp*TaCl₂(μ‐OH)]₂(μ‐O) (8c) and A . Analogous reactions of Cp*NbCl₄ (1b) with A were used to prepare the azide‐rich dinuclear products [Cp*NbCl_3‐n(N₃)_n(μ‐N₃)]₂ (n = 2 (4b) , and n = 3 (5b) ), and [Cp*NbCl(N₃)(μ‐N₃)]₂(μ‐O) (7b) . The mononuclear complex Cp*Ta(N₃)Me₃ (10c) is obtained from Cp*Ta(Cl)Me₃ and A . All azido complexes were characterised by their IR as well as their ¹H and ¹³C NMR spectra; X‐ray crystal structure analyses are available for 6c and 7b .