Sesterterpene metabolites from the sponge Hyatella intestinalis

The sponge Hyatella intestinalis from the Gulf of California contains the new scalarane-related sesterterpenes hyatelones A-C and hyatolides A-B, together with the new scalaranes hyatolides C-E, hyatelactam, 12-O-deacetyl-19-epi-scalarin and the new norscalarane 12-O-deacetylnorscalaral B. The structures of the new metabolites have been established by spectroscopic analysis of the natural products and, in some instances, of their acetyl derivatives. The new compounds hyatelone A, 19,20-di-O-acetylhyatelone B, hyatolide A, 20-O-acetylhyatolide C, hyatelactam, and 12-O-deacetylnorscalaral B have shown activity as growth inhibitors of several tumor cell lines.     

Synthese und Kristallstruktur von Tetraphenylphosphonium-Aquabis(tetrasulfido)thionitrosyl-Osmat,PPh4[Os(NS)(S4)2(H2O)]

Synthesis and Crystal Structure of Tetraphenylphosphonium Aqua-bis(tetrasulfido)thionitrosyl Osmate, PPh₄[Os(NS)(S₄)₂(H₂O)] PPh₄[Os(NS)(S₄)₂(H₂O)] has been prepared as redbrown crystals by reacting PPh₄[OsNCl₄] with a solution of excess disodium tetrasulfide in dimethylformamide/H₂O and characterized by IR spectroscopy and by a crystal structure determination. Space group P2₁/n, Z = 4, structure solution with 4162 independent reflections, R = 0.059 for reflections with I > 2σ(I). Lattice dimensions at ?40°C: a = 1138.9(5), b = 1301.4(4), c = 2092.7(7) pm, β = 104.74(3)º. Os? N, Os? O, and Os? S distances are 175.2(12), 219.8(12), and 237.5(4)?239.1(4) pm, respectively. The Os?N?S moiety is approximately linear, with an OsNS angle of 171.2(7)º.     

π‐Stacking Modulates the Luminescence of [(dppz)Ni(Mes)Br] (dppz = dipyrido[3,2‐a:2′,3′‐c]phenazine,Mes = 2,4,6‐trimethylphenyl)

The red colour of the novel organonickel complex [(dppz)Ni(Mes)Br] (dppz = dipyrido[3,2‐a:2′,3′‐c]phenazine, Mes = 2,4,6‐trimethylphenyl) originates from long‐wavelength MLCT/L′LCT charge transfer bands. However, luminescence in dilute solution comes presumably from the ³π‐π* (phenazine) excited state. The red‐shifted emission exhibited in concentrated solutions is assigned to dimers. In the solid state emission is quenched. The crystal structure reveals two different types of π‐π stacking along the crystallographic a axis.     

P,P′-(2,5-Dimethoxy-3,6-dimethyl-2,5-dioxo-2λ5,5λ5-[1,4,2,5]dioxadiphosphinan-2,5-diyl)-bis-phosphonsäuretetramethylester

P,P′-(2,5-Dimethoxy-3,6-dimethyl-2,5-dioxo-2λ⁵,5λ⁵-[1,4,2,5]dioxadiphosphinane-2,5-diyl)-bis-phosphonic acid tetramethylester The title compound 1 is formed by reaction of the corresponding phosphonic acid 2 and orthoformicacidmethylester as a mixture of four stereoisomeres. The RRSS isomer was separated. It crystallizes in the triclinic space group P ?1 with a = 649.2 pm, b = 976.1 pm, c = 1 571.7 pm, α = 80.9°, β = 88.1°, γ = 78.6° and Z = 2. The ³¹P and ¹³C NMR spectra (4 and 5 spin systems) are discussed.     

Halogeno-Nitrosylkomplexe von Molybdän und Wolfram. Die Kristallstrukturen von [Na2(15-Krone-5)2(CH3CN)][MoCl4(NO)2] und [Na(15-Krone-5)]2[MoF4Cl(NO)]

Halogeno-Nitrosyl Complexes of Molybdenum and Tungsten. Crystal Structures of [Na₂(15-Crown-5)₂(CH₃CN)][MoCl₄(NO)₂] and [Na(15-Crown-5)]₂[MoF₄Cl(NO)] MoCl₂(NO)₂ and WCl₂(NO)₂, respectively, react with excess sodium fluoride in acetonitrile at room temperature and in the presence of 15-crown-5 to give crystalline mixtures, which consist of the title compounds, respectively of [Na(15-crown-5)]₂[WCl₄(NO)₂] and [Na(15-crown-5)]₂[WF₄Cl(NO)], and which can be separated by selection. The complexes are characterized by their i.r. spectra, the molybdenum compounds additionally by crystal structure determinations. [Na₂(15-crown-5)₂(CH₃CN)][MoCl₄(NO)₂]: Space group P2₁, Z = 2, 5415 independent unique reflexions, R = 0.039. Lattice dimensions at ?10°C: a = 984.3, b = 1231.1, c = 1483.0 pm, β = 105.67°. The compound consists of cations [Ne(l5-crown-5)(CH₃CN)]⁺, in which the sodium ion is surrounded by the five O-atoms of the crown ether and by the N-atom of the acetonitrile molecule, as well as of anions, which form an ion pair {Na(15-crown-5)[MoCl₄(NO)₂]}^?. In the in pairs the sodium ion is coordinated by the five oxygen atoms of the crown ether and by two chlorine atoms of the [MoCI₄(NO)₂]^2? unit. The nitrosyl ligands take the cis-position a t the molybdenum atom which is in a distorted octahedrally fashion. [Na(15-crown-5)]₂[MoF₄Cl(NO)]. Space group C2/c, Z = 4, 1933 independent unique reflexions, R = 0.078. Lattice dimensions at ?7O°C: D : 1.585.8, b = 1171.5, c = 1771.5 pm, β = 114.91°. The compound forms an ion triple, in which the sodium ions are linked to five oxygen atoms each of the crown ether molecules, and to two F-atoms of the [MoF₄Cl(NO)]^2? unit. The F-atom which is arranged in trans-position to the nitrosyl ligand coordinates with both sodium ions; thus an unusual T-shaped arrangement results for this F-atom. The sole terminal F-Atom and the Cl-atom are disordered in two positions.     

金属Ni熔化前后结构变化的分子动力学模拟

使用Tight-binding势函数, 对FCC-Ni升温熔化过程的结构变化进行了分子动力学模拟. 在定压条件下模拟得到的Ni的熔点在1850 K与1900 K之间. 计算得到了体系在各温度下的径向分布函数和配位数分布等静态结构信息以及动力学性质. 计算得出的液体Ni的扩散系数在1900 K时约为5.02×10−9 m2•s−1, 与实验数据相符. 对液态体系中FCC短程有序结构可能发生的畸变以及由此导致的H-A键型变化进行了分析, 结合配位体构型搜索和键对分析方法计算了各温度下不同短程有序结构的分布. 计算表明, Ni在熔化之后仍保留有部分晶态短程结构, 但发生了较大的畸变, 同时液态中有少量的缺陷二十面体结构存在. 而液体Ni中大多数的配位体的几何构型介于FCC与缺陷二十面体之间.     

仿贝壳结构的自组装有机-无机纳米复合薄膜的制备及结构表征

利用超分子自组装法在玻璃表面制备了聚合前后DMTB/SiO2和DMCB/SiO2复合薄膜.在所制备的复合薄膜中,表面活性剂DMTB和DMCB既作结构导向剂,又作聚合单体.用FTIR,XRD和TEM等表征了薄膜的结构.结果表明,所制备的薄膜具有有机-无机有序交替的层状结构.DMCB/SiO2和DMTB/SiO2复合薄膜有机层与无机层间的距离分别为聚合前3.48和3.44nm,聚合后2.84和2.92nm.     

The Structure of cis‐[Chloro(dimethylsulfoxide)bis(1, 10‐phenanthroline)ruthenium(II)]‐tetraphenylborate, [RuCl(DMSO)(1, 10‐phen)2][BPh4]

The complex cis‐[RuCl(DMSO)(phen)₂]BPh₄, where DMSO is dimethylsulfoxide and phen is 1, 10‐phenanthroline, crystallizes in the monoclinic space group P2₁/c with a = 19.505(4), b = 10.045(2), c = 21.199(4) Å, β = 90.137(4)°, V = 4153(2) ų, Z = 4, D_calc = 1.430 g cm^—3. The ruthenium coordination geometry is that of a slightly distorted octahedron with a cis‐RuN₄ClS arrangement of the ligand donor atoms. The Ru—Cl distance is 2.421(1) Å and the Ru—S distance 2.250(2) Å. The four Ru—N distances are 2.057(6), 2.066(4), 2.073(4), and 2.086(4) Å with the Ru—N bond trans to Cl the second shortest and the Ru—N bond trans to S the longest one.     

Hydrothermal Synthesis, Crystal Structure and Electrochemical Properties of the Complex Cu(o-Methylbenzoic acid)2(2,2''-bipy)·(H2O)

The title complex (C26H24CuN2O5, Mr = 508.01) has been synthesized by o-methylbenzoic acid, 2,2'-bipyridine (bipy) and copper perchlorate in the mixed solvent of water and methanol. It crystallizes in orthorhombic, space group P212121 with a = 0.70814(10), b = 1.6953(3),c = 1.9539(3) nm, V= 2.3457(6) nm3, Dc= 1.439 g/cm3, Z= 4,μ = 0.971 mm-1, F(000) = 1052, R= 0.0432 and wR = 0.0860. The structural determination shows that the copper atom is coordinated by three oxygen atoms from two o-methylbenzoic acids and one water molecule together with two nitrogen atoms from 2,2'-bipyridine, giving a distorted square-pyramidal coordination geometry.The cyclic voltammetric behavior of the complex is also discussed.     

Recent Advances in the Chemistry of “Clusters” and Coordination Polymers of Alkali,Alkaline Earth Metal and Group 11 Compounds

This contribution gives an overview on the different subjects treated in our group. One of our fundamental interests lies in the synthesis and study of low‐dimensional polymer and molecular solid state structures. We have chosen several synthetic approaches in order to obtain such compounds. Firstly, the concept of cutting out structural fragments from a solid state structure of a binary compound will be explained on behalf of BaI₂. Oxygen donor ligands, used as chemical scissors on BaI₂, allow obtaining three‐, two‐, one‐ and zero‐dimensional derived compounds depending on their size and concentration. Thus, a structural genealogy tree for BaI₂ can be established. This method, transferred to alkali halides using crown ethers and calix[n]arenes as delimiting ligands, leads us to the subject of one‐dimensional ionic channels. A second chapter deals with the supramolecular approach for the synthesis of different dimensional polymer structures derived from alkaline earth metal iodides, and based on the combination of metal ion coordination with hydrogen bonding between the cationic complexes and their anions. Under certain circumstances, rules can be established for the prediction of the dimensionality of a given compound, thus contributing to the fundamental problem of structure prediction in crystal engineering. A third part describes a fundamentally new synthetic pathway for generating pure alkaline earth metal cage compounds as well as alkali and alkaline earth mixed metal clusters. In a first step, different molecular precursors, such as solvated alkaline earth metal halides are investigated as a function of the ligand size and reactivity. They are then reacted with some alkali metal compound in order to partially eliminate alkali halide and to form the clusters. The so obtained unique structures of ligand stabilized metal halide, hydroxide and/or alkoxide and aryloxide aggregates are of interest as potential precursors for oxide materials. Approaches to two synthetic methods of the latter, sol‐gel and (MO)‐CVD, are investigated with our compounds. In order to generate single source precursors for oxide materials, we started to investigate transition metal ions, especially Cu and Ag, using multitopic ligands. This has led us into the fundamental problematic of “crystal engineering” and solid state structure prediction and we found ourselves confronted to numerous interesting cases of polymorphism and pseudo‐polymorphism. Weak interactions, such as π‐stacking, H‐bonding and metal‐metal interactions, and solvent, counter ion and concentration effects seem to play important roles in the construction of such low‐dimensional structures. Finally, the physical properties of some of our compounds are described qualitatively in order to show the wide spectrum of possibilities and potential applications for the chemistry in this field.