Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. 63. Darstellung und Kristallstruktur von Tetramethyltitan-tetrahydrofuran

Contributions to the Chemistry of Transition Metal Alkyl Compounds. 63. Preparation and Crystal Structure of Tetramethyltitanium Tetrahydrofuran Me₄Ti · 2THF 1 dissoziates partially in n-pentane. The formed Me₄Ti · THF 2 could be isolated. According to X-ray structure determination the molecules of 2 have a trigonalbipyramidal shape with the THF molecule in axial position.     

Synthese und Struktur von Li3RhH6, einem ternären Hydrid mit isolierten [RhH6]3−-Oktaedern

Synthesis and Structure of Li₃RhH₆ — a Ternary Hydride with Isolated [RhH₆]^3? Octahedra The ternary rhodium hydride Li₃RhH₆ was synthesized by the reaction of lithium hydride with rhodium under a hydrogen pressure of 80 bar. X-ray investigations on powdered samples and an elastic neutron diffraction experiment on the deuterated compound led to the complete structure determination (space group: Pnma, Z = 4). The atomic arrangement is isotypic to the Na₃RhH₆ structure type. The crystal structure contains isolated [RhH₆]^3? octahedra, which are separated by the lithium ions.     

新型化合物[Ni(en)3]2[Ni(en)2(H2O)2][As6V15O42]·4H2O晶体的水热合成与表征

金属氧酸盐因其在医药临床、工业催化、功能材料等方面的广泛应用而引起人们的关注[1～6], 其中, 有关钒化学的研究一直很活跃, 钒具有与钼、钨明显不同的结构特性, 钒可以采取VO4, VO5和VO6方式配位, 同时, 钒的价态可以是+3, +4和+5价. 由于钒可采取多种配位方式及多种价态, 与钼酸盐和钨酸盐相比, 钒酸盐更具有结构柔顺性, 同时易形成低价或混合价态物种.在以往的文献中, 有关P-V-O体系多金属氧酸盐的水热合成的研究已有大量的报道[7], 在常规溶液合成中, 人们已对As-V-O体系进行了相对深入的研究, 而有关水热合成的研究报道却很少, 已见报道的砷钒化合物有K6*6H2O[8,9], 4-[10], 6-[11](X=SO2-3, SO2-4, H2O). 为了探究水热条件下As-V-O体系的反应特性, 我们开展了这方面的研究工作, 并取得了突破性进展. 本文采用中温水热技术合成了含有机基团的砷矾超分子化合物2**4H2O, 探讨这类化合物的非线性光学性质、催化性质及其它功能特性将是一个非常有意义的研究领域.     

Synthesis, crystal structure and studies on properties of trisodium 5,3′,5′-trisulfonate-2,3,4,4′-tetrahydroxy-deoxybenzoin

A new water soluble compound trisodium 5,3′,5′-trisulfonate-2,3,4,4′-tetrahydroxy-deoxybenzoin (TTDB) was synthesized and characterized by IR, UV, ¹H NMR, and elemental analysis. The single crystal of TTDB was determined by X-ray single crystal diffraction. The scavenging effect of compounds on hydroxy radicals was detected by fluorescent spectrophotometry. The electrochemical behavior of compounds in nonaqueous solution DMF was carried out by means of cyclic voltammetry. The experimental result shows that the crystal [C₁₄H₁₇Na₃O₁₈S₃] belongs to monoclinic, space group C2/c with unit cell constants a = 1.4223(4) nm, b = 2.4327(8) nm, c = 1.3596(4) nm, α = 90°, β = 113.044(5)°, γ = 90°, Z = 8, V = 4.329(2) nm³, D _c = 1.925 mg/m³, F(000) = 2568, F _w = 638.43, R ₁ = 0.0950, wR ₂ = 0.2648. The half effective concentration EC₅₀ of scavenging hydroxy radicals of compound THDB is 53.1 μmol/L, while that of scavenging hydroxy radicals of compound TTDB is 47.3μmol/L. The electrochemistry redox processes of THDB and TTDB are different from each other. __________ Translated from Chemical Journal of Chinese Universities, 2005, 26(9) (in Chinese)     

Coordination chemistry of 2,6-bis(diphenylphosphorylmethyl)-4-methylphenol

The trifunctional ligand, 2,6-bis(diphenylphosphorylmethyl)-4-methylphenol (L ₂), forms complexes with cerium(III) nitrate having a ligand to metal ratio of 1: 1, 2: 1, and 3: 1. The structures of these complexes in the solid state and in solution were studied by X-ray diffraction, IR and NMR (¹H and ³¹P) spectroscopy, and conformational analysis (molecular mechanics). The 2: 1 complexes of L ₂ with lanthanum(III) and neodymium(III) nitrates were synthesized and characterized. In all complexes, the neutral ligand is coordinated through both phosphoryl oxygen atoms. The hydroxy oxygen atom is coordinated only in some complexes, and the hydrogen atom of the hydroxy group is involved in hydrogen bonding. The compositions and structures of the resulting complexes depend on the method of synthesis and the nature of solvent. The ligand was found to undergo easy inner-sphere oxidation. The structure of one of the transformation products was established by X-ray diffraction. Unlike the coordinated ligand, the free ligand is very stable to oxidation. Dedicated to Corresponding Member of the Russian Academy of Sciences T. A. Mastryukova. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2440–2454, November, 2005.     

Darstellung und Kristallstruktur von Rb2Ni3Se4

Preparation and Crystal Structure of Rb₂Ni₃Se₄ The compound Rb₂Ni₃Se₄ was synthesized by heating a mixture of rubidium carbonate, nickel and selenium at 850°C in an atmosphere of hydrogen. The compound has a golden lustre and crystallizes with the K₂Pd₃S₄-type structure; a = 10.555(3) Å, b = 27.588(6) Å, c = 6.031(6) Å, Z = 8, Fddd (No. 70). The structure can be described as a stacking of layers of the composition Rb₂Ni₃Se₄ with a stacking sequence abcd. The electrostatic part of lattice energy (MAPLE) will be discussed for compounds of the compositions A₂M₃X₄ (A K, Rb, Cs; M Ni, Pd, Pt and X S, Se).     

Influence of conjugated nitrogenous bases on the spectra and structure of mixed-ligand nickel(II) chelates containing β-diones

The infrared and electronic excitation spectra of a series of new nickel(II) chelates containing an-diimine (or nitrogenous base, enR) and the anion of a-dione (1,3-ketoenol or 1,3-ketoester,H) were obtained in the solid state and in solution. The composition and the overall structure of the new chelates in the solid state depends on ligand concentration, the substituents within the-dionato moiety and the counterion present. The IR and electronic excitation spectra of [Ni(enR)₂ ]NO₃ and [Ni(enR)(O₂NO)] indicate, in conjunction with other physicochemical measurements, bidentate coordination of the ligands, while the spectral shifts reveal replacement of the (O,O)nitrato group by basic solvents. The existence of the nickel(II) in an octahedral environment is confirmed by an X-ray structure analysis of [Ni(dpamH)₂acac]NO₃ · CH₃OH (monoclinic, space groupP2_l/n, a=17.296(1),b=7.462(1),c=21.604(3) å,=95.65(1),Z=4, R=0.0534,Rw=0.0600), where dpamH denotes the 2,2-dipyridylamine.     

Crystal Structure of (6S,9S,13R,14S)-7,8-Didehydro-3,7-dimethoxy-17-methylmorphinan-4,6-diol

1 INTRODUCTION (9S,13R,14S)-7,8-Didehydro-3,7-dimethoxy-4-hydroxy-17-methylmorphinan-6-one I is an impor- tant natural product that was used to ease pain, decrease blood pressure and diminish inflammation. In order to study the stereochemistry of the reduction of I with potassium boronhydride, the crystal structure of the title compound II was determined by X-ray diffraction method. 2 EXPERIMENTAL 2. 1 Instrument The melting point was measured on a Yanagimoto MP-500 apparatus…     

Preparation and reactivity of metal-containing monomers

Mono- and disubstituted cluster metal-containing monomers were obtained under mild conditions on interaction of Rh₆(CO)₁₆ with 4-vinylpyridine (4-ViPy) in the presence of N-trimethylaminoxide. These products were characterized by IR and¹H NMR spectroscopy and by elemental and X-ray analyses. Rh₆(CO)₁₅(4-ViPy) was found to be an octahedral cluster with eleven terminal and four ₃-bridging carbonyl ligands. 4-ViPy is linked with the Rh(3) atom through the N atom and occupies the coordination site of the twelfth CO terminal ligand. The mean value of the Rh-Rh bond length is 2.762 Å. The unsaturated ligand has little or no effect on the geometry of the starting cluster and its double bond retains the ability to undergo addition reactions.For part 28, seeRuss. Chem. Bull., 1993, 453.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 975–979, May, 1993.