Darstellung und spektroskopische Eigenschaften von Nitridophthalocyaninatorhenium(V)

Preparation and Spectroscopical Properties of Nitridophthalocyaninatorhenium(V) Nitridophthalocyaninatorhenium(V) ([ReNPc^2?]) is prepared by the reaction of dirheniumheptoxide with ammoniumiodide in molten 1,2-dicyano-benzene. The diamagnetic complex is chemically und thermically extremely stable. In the Uv-vis spectra the typical π-π*-transitions of the Pc^2? ligand are observed. Extra bands in the solid state spectrum are due to strong excitonic coupling of ca. 2.8 kK. In the resonance Raman spectra the intensity of the Re≡N stretching vibration (v(Re≡N)) at 969 cm^?1 is selectively enhanced by laser excitations above 19.0 kK. v(Re≡N) is a dominant m.i.r. absorption at 976 cm^?1.     

Metal ion distribution and solubility of Mn1−xCux(HCOO)2 · 2 H2O Mixed Crystals [1–5]

The metal ion distribution on the two metal sites of monoclinic Mn_1?xCu_x(HCOO)₂ · 2(H,D)₂O mixed crystals are studied by infrared and Raman spectroscopic methods. The spectral regions 3 200–3 400 cm^?1 (v_OH), 2 875–2 990 cm^?1 (v_CH), 2 330–2 500 cm^?1 (v_OD of matrix isolated HDO molecules), 1 350–1 400 cm^?1 (symmetric CO₂ stretching modes), 570–950 cm^?1 (H₂O librations), and 490 cm^?1 (M? O lattice modes) are mostly sensitive to the metal ions present. The frequency shifts of these bands with increasing content of copper show that Cu²⁺ prefers the M(1) site, coordinated by HCOO^? only. The strengths of the hydrogen bonds increase on going from manganese to copper formate, due to the increased synergetic effect of Cu²⁺. Solubility and X-ray data of the mixed crystals are included. Irrespective of the same crystal structure, two series of mixed crystals are formed: eutonic area at 0.65 ≥ x ≥ 0.5.     

Transition Metal Atom Sites in Ternary ZrO2-TiO2-SiO2 Xerogels

There has been much work on the binary TiO₂-SiO₂ and ZrO₂-SiO₂ materials prepared by sol-gel because of the beneficial properties resulting from incorporation of Ti and Zr. In contrast the ternary TiO₂-ZrO₂-SiO₂ xerogels have been relatively little studied. We report the results of a study of those xerogels having Zr:Ti:Si ratios of 5:15:80, 10:10:80 and 15:5:80 heated to 750°C and to 1000°C. The study includes X-ray diffraction, small angle X-ray scattering, X-ray absorption spectroscopy at Ti and Zr K-edges, and ¹⁷O MAS-NMR. The study has benefited from close comparison with similar previous studies of the binary systems. The metal atoms in the ternary systems are shown to be predominantly homogeneously mixed in the silica network, as observed for the respective binary systems. The clear exception is for the sample with a minority of Zr, which after heat treatment at 750°C shows the presence of phase separation attributed to the formation of an amorphous precursor of ZrTiO₄; at 1000°C this phase crystallises. In samples with higher Zr content the crystallisation of a ZrO₂ tetragonal phase was observed. The data obtained illustrate well the strength of a research methodology in which a common batch of samples is studied using a coherent suite of modern structural probes.     

Chiral resolution of diphenylalanine by high-performance liquid chromatography on a crown-ether-based chiral stationary phase and by NMR spectroscopy

Summary The enantiomers of diphenylalanine (DPA) were well separated by chiral HPLC and NMR spectroscopy on the chiral stationary phase (CSP) derived from (18-crown-6)-2,3,11,12-tetracarboxylic acid (18-C-6-TA). The chromatographic parameters such as separation factors and retention times were greatly influenced by the mobile phase conditions. The (+)-18-C-6-TA used in the CSP was also employed as a chiral solvating agent for the enantiodiscrimination of the DPA enantiomers by NMR spectroscopy. The proton of the DPA analyte showing the chemical shift nonequivalences was used in determining the enantiomeric composition of the analyte.     

Thermal and other properties of complexes of Mn(II), Co(II) and Ni(II) with 2,2'-bipyridine and trichloroacetates

Complexes of the general formulae Mn(2-bpy)₂(CCl₃COO)₂, Co(2-bpy)₂(CCl₃COO)₂·H₂O and Ni(2-bpy)₂(CCl₃COO)₂·2H₂O (where: 2-bpy=2,2'-bipyridine) have been prepared and characterized by VIS and IR spectroscopy, conductivity and magnetic measurements. The thermal properties of complexes in the solid state were studied under non-isothermal conditions in air atmosphere. During heating the complexes decompose via different intermediate products to the oxides Mn₃O₄, CoO and NiO. A coupled TG-MS system was used to detection the principal volatile products of thermal decomposition and fragmentation processes of obtained compounds. The principal volatile products of thermal decomposition of complexes are: H₂O⁺, CO₂ ⁺, Cl₂ ⁺ and other. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal properties of rare earth elements complexes with 1,3,5-benzenetricarboxylic acid

Summary Rare earth elements 1,3,5-benzenetricarboxylates were prepared as solids of the general formula Ln(C₉H₃O₆)·nH₂O, where n=6 for La-Dy and n=4 for Ho-Lu,Y. Their solubilities in water at 293 K are of the order 10^-4-10^-6 mol dm^-3. The IR spectra of the complexes indicate that the carboxylate groups are bridging and bidentate chelates. Hydrated 1,3,5-benzenetricarboxylates lose water molecules during heating in one step (La-Tb), two steps (Y, Ho-Tm) or three steps (Dy, Yb, Lu). The anhydrous complexes are stable up to 573-742 K and decompose to oxides (Ce-Lu) at higher temperatures.     

Additional Isoquinoline Alkaloids from Lltsea Cubeba

By combination of centrifugal partition chromatography (CPC) and common separation methods, seven additional known bases were isolated and characterized from the reinvestigation of L. cubeba besides three previously isolated bases- isocorydine (10), N-methyllaurotetanine (9), and boldine (2). They are laurolitsine (1), laurotetanine (3), isoboldine (4), norisocorydine (5), N-methyllindcarpine (7), isodomesticine (8), and glaziovine (6). Among these, compound 9 is the most abundant (7.5 × 10^?4) and will be modified for pharmacological tests. This work will be of value for chemotaxonomy.     

水杨酰腙与磷酰二氯的缩合反应

一些水杨酸的衍生物具有生物活性早有报道.本文研究水杨酰腙与硫代磷酰二氯或磷酰二氯缩合时可能发生的不同关环方式,并通过对反应产物的生物活性测定寻找有效的杀菌剂. 我们发现,在三乙胺存在下水杨酰腙1与硫代磷酰二氯2在四氢呋喃中反应主要以酮式关环生成3类化合物,而与磷酰二氯反应则主要以烯醇式关环生成4类化合物.     

2,4,5-三氧-1,3,2,4-二氮二磷杂环戊烷衍生物的合成和结构

本文报道了七个新的2,4,5-三氧-1,3,2,4-二氮二磷杂环戊烷衍生物的制备, 产物的结构经IR, ^1H和^31P NMR, MS以及元素分析证实, 并利用^31P NMR和GC-MS区分了化合物的顺式和反式异构体。