Published by De Gruyter

Volume 51 Issue 12

Issue of Zeitschrift für Naturforschung B

Contents
Journal Overview

Open Access June 2, 2014

Gold(I) Complexes of Chiral Secondary Phosphines

Klaus Angermaier, Alexander Sladek, Hubert Schmidbaur

Page range: 1671-1674

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Abstract

The reaction of (dimethylsulfide)gold(I) chloride and bromide with methyl(phenyl)phosphine in ṯetraẖydrof̱uran affords high yields of the colorless, crystalline, chiral complexes [Me(Ph)HP]AuCl/Br ( 1a, b). Treatment of la with potassium iodide in thf leads to a conversion into the corresponding iodide [Me(Ph)HP] Aul ( 1c). The compounds were characterized by their analytical and spectroscopic data, and the crystal structures of la, b have been determined. The two compounds are isomorphous. In the lattice the monomers form chain-like supramolecular aggregates through auriophilic Au-Au contacts. The chains contain both enantiomers following the sequence ..R S R S R S.., with the individual components related by crystal symmetry.

Open Access June 2, 2014

Ein zweikerniger Vanadium(V)-Komplex mit (μ¹)- und (μ-μ²:μ²)-gebundenen Hydrazido(2-)-Liganden / A Dinuclear Vanadium(V) Com plex with (μ¹)- and (μ-μ²:μ²)-Bonded Hydrazido(2-) Ligands

Klaus Kopka, Rainer Mattes

Page range: 1675-1678

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Abstract

The title complex was obtained by reaction of guanidinium dioxodipicolinatovanadate(V) and N-methyl-N-phenylhydrazine. According to the single crystal structure analysis the dinuclear anion [(μ-PhNNH)(μ-OCH 3 ){(MePhNN(dipic)V)} 2 ] - with sevenfold coordinated metal centers contains two types of hydrazido ligands. The ligand [MePhNN] 2- is terminally bonded, and the VNN unit is linear with extensive electron delocalisation. The V-N and N-N bond lengths are 167.9(5) and 131.9(6) pm, respectively. The bonding of the bridging ligand is of the hitherto unknown μ-μ 2 :μ 2 type, with V-N and N-N bond lengths of 202.5(5) and 136.5(5) pm, respectively. The V(N 2 )V moiety is not planar. The compound was also characterized by 1 H and 51 V NMR spectroscopy.

Open Access June 2, 2014

Synthesis and Characterization of Bis(3-chloro-4-dodecyloxyphenyl) Malondialdehyde Complexes of Cu(II) and Ni(II)

V. Salas-Reyes, G. Soto-Garrido, C. Aguilera

Page range: 1679-1682

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Abstract

Bis (3-chloro-4-dodecyloxyphenyl) malondialdehyde copper(II), as well as its nickel(II) homologue have been synthesised. The copper(II) complex shows a narrow (15 °C) nematic phase below its clearing temperature. The nickel(II) complex is polymeric in nature.

Open Access June 2, 2014

Asymmetrie Ethynes. Syntheses of Ethynylferrocene Paradigms

Johann Polin, Herwig Schottenberger, Karl Eberhard Schwarzhans

Page range: 1683-1690

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Abstract

Synthetic methods to bifunctional ethynes have been examined. Direct ethynylation, the Stephens-Castro reaction, the Pd-catalysed Hagihara coupling, transmetalation reactions and nucleophilic additions have been evaluated in the preparation of substituted ferrocenylethynes with intended use of these materials in electrochemical and nonlinear optical investigations. Asymmetric ferrocenylethynes are promising candidates for applications in contemporary materials science. Synthetically, 1,4-bis(ferrocenylethynylene)benzene (1), 1,3,5-tris(ferrocenylethynylene) benzene (2), and 9 ,10-bis(ferrocenylethynylene)anthracene (3) are obtained in high yields, whereas 4-ferrocenylethynylene-2,3,5,6-tetrafluorostyrene (4) and potassium (ferrocenylethynylene) triphenyl borate (5) are accessible in only moderate yields. Further extension of this chemistry to additional heteronuclear bimetallic coordination compounds has been attempted, but without success due to severe difficulties in both preparation and characterization of these materials.

Open Access June 2, 2014

Untersuchungen zur Säurestärke von Alkanpolysulfonsäuren / Investigations on the Acid-Strength of Alkanepolysulfonic Acids

Ralf Jüschke, Peter Sartori

Page range: 1691-1700

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Abstract

The acid strength of alkanepolysulfonic acids was measured using the correlation between the 29 Si NMR shift of the corresponding trimethylsilylester of an acid and the pK S1 -value of the acid. Alkanepolysulfonic trimethylsilylesters XHC(SO 3 -SiMe 3 ) 2 , X 2 C(SO 3 -SiMe 3 ) 2 , XC(SO 3 - SiMe 3 ) 3 and Me 3 Si-O 3 S-(CR 2 ) n -SO 3 -SiMe 3 with X = H, F, Cl, Br, I and R = H, F and n = 1 - 5 were investigated.

Open Access June 2, 2014

Metallkomplexe mit Cyanoguanidin als Liganden: Kristallstrukturen von [Cd(cnge)₂F₂]·3H₂O , Cd(cnge)₂Br₂ und Hg(cnge)Cl₂ (enge = C yanoguanidin) / Metal Complexes with Cyanoguanidine as Ligand: Crystal Structures of [Cd(cnge)₂F₂]·3H₂O, Cd(cnge)₂Br₂ and Hg(cnge)Cl₂ (cnge = Cyanoguanidine)

Joachim Pickardt, Britta Kühn

Page range: 1701-1706

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Abstract

Crystals of [Cd(cnge) 2 F 2 ]·3H 2 O (1), Cd(cnge) 2 Br 2 (2) and Hg(cnge)Cl 2 (3) (cnge = cyanoguanidine) were obtained by crystallisation from solutions of CdF 2 , CdBr 2 or HgCl 2 and cyanoguanidine in water/ethanol or methanol. 1 crystallizes monoclinically, space group C2, Z = 2,a = 1629.2(4), b = 1056.6(4), c = 353.9( 1) pm, β = 101.05(2)°; 2 is monoclinic, space group P2 1 /n, Z = 2, a = 391.9(1), b = 850.7(2), c = 1722.1(4) pm, β = 94.06(2)°, 3 is triclinic, space group P1, Z = 1, a = 686.7( 1), b = 693.0(5), c = 387.2(4) pm, α = 94.45(5)°, β = 95.05(4)°, γ = 78.58(5)°. In 1 and 2 each Cd atom is bonded to four halogen atoms to form polymeric (CdF 2 ) n and (CdBr 2 ) n chains, resp., and to two cyanoguanidine molecules. In 3 each Hg atom is bonded to four chlorine atoms also forming (HgCl 2 ) n chains, which are connected via cyanoguanidine molecules acting as a bidentate bridging ligands to form a network.

Open Access June 2, 2014

Reaction of Borane in Tetrahydrofuran with 1,1,3,3-Tetramethyldisilazane and Cyclic Disilazanes - Competition Between N-Si and N-H Bond Cleavage

Bernd Wrackmeyer, Bernd Schwarze

Page range: 1707-1715

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Abstract

Borane in tetrahydrofuran (THF-BH 3 /THF; 1) reacts with 1,1,3,3-tetramethyldisilazane (2a) and the cyclic disilazanes (2b), 3 (2c), 4 (2d)] first by formation of amine-borane adducts (3a - d), and then to give /μ-aminodiboranes(6) by H 2 elimination (4a -,d) or cleavage of N-Si bonds (5a-d ), depending on the reaction conditions, in agreement with the results obtained for the reaction of 1 with hexamethyldisilazane. Further transformations proceed via the N,N-disilylaminoboranes 6a - d. In the case of the reaction between 1 and 2b, it proved possible to convert 4b and/or 5b quantitatively into the mixed diaminoborane 7b which served for the synthesis of N,N′,N″-tris[(2′-dimethylsilylethyl)dimethylsilyl]borazine (8b). The Si-H functions in 5b, 7b and 8b react with Co 2 (CO) 8 to afford the respective Si-Co(CO) 4 derivatives 11b - 13b. All compounds were characterized by their 1 H , 11 B, 13 C, 14/15 N and 29 Si NMR spectra.

Open Access June 2, 2014

Heterometallische Mehrkernkomplexe von Zink und Cadmium mit cis-[Cr(OH)₂(en)₂]⁺-Liganden / Heterom etallic Polynuclear Complexes of Zinc and Cadmium with cis-[Cr(OH)₂(en)₂]⁺ Ligands

Frank Rominger, Ulf Thewalt

Page range: 1716-1724

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Abstract

A series of polynuclear heterometallic complexes containing chromium and zinc or cadmium were prepared by the reaction of cis-[CrCl 2 (en) 2 ]Cl and a zinc or cadmium salt in water and the molecular and crystal structures of 1 to 5 determined by X-ray structure analyses. The products contain chelating or bridging cis-[Cr(OH) 2 (en) 2 ] + groups. For the zinc complexes a tetrahedral coordination is observed, and the [Cr(OH) 2 (en) 2 ] + units are found to act as bridges. [[ZnCl 2 (μ-OH)Cr(en) 2 (μ-OH)]ClO 4 ] n (1) has a chain polymeric structure. [{ZnCl 2 (μ-OH)Cr(en) 2 (μ-OH)} 2 ]Cl 2 (2) has a cyclic structure. In the case of the cadmium complexes the [Cr(OH) 2 (en) 2 ] + units act as chelating ligands. For the three cadmium complexes [Cd 3 (μ-Cl) 4 Cl 4 {Cr(μ3-OH)(μ-OH)(en) 2 } 2 ]·4H20 (3), [[Cd(μ-Cl)(H 2 O) 2 {Cr(μ-OH) 2 (en) 2 }](ClO 4 )(NO 3 )·2H 2 O] n ; (4), and [Cd 2 (μ-Cl)2Cl 3 (H 2 O) 3 { Cr(μ-OH) 2 (en) 2 }] n ; (5) an octahedral coordination sphere is observed. The cadmium atoms in 3 to 5 are connected by at least one chloro bridge. In the centrosymmetrical pentanuclear complex 3 bridging occurs by face-sharing, and in the chain polymeric complexes 4 and 5 by edge-sharing of the coordination octahedra. In the crystal structures of all complexes a network of hydrogen bonds is observed, which contributes substantially to the stability of the conformation of the chain structures.

Open Access June 2, 2014

Ein neuer Heterocyclus, 2λ³,4λ⁵-[1,2,4]-Oxadiphosphinin (2), als Ligand eines zweikernigen Eisenkomplexes / A New Heterocycle, 2λ³, 4λ⁵ -[1,2,4]-Oxadiphosphinine (2), as Ligand of a Binuclear Iron Complex

Fred Rosche, Gernot Heckmann, Frank Weller, Ekkehard Fluck

Page range: 1725-1731

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Abstract

Preparation and properties of a coordination compound are described, in which a carbonyl group in bis[(dicarbonyl)(μ 5 -cyclopentadienyl)iron] is substituted by hitherto unknown octa- N-methyl-2λ 3 ,4λ 5 -[1,2,4]-oxadiphosphinine-2,4,4,6-tetramine (2). The 1 H , 31 P, and 13 C NMR spectra are recorded and discussed in detail. The molecular structure of the iron complex 4 is described and interpreted.

Open Access June 2, 2014

Synthese, Kristallstruktur und Eigenschaften von 1,1,1,3,3, 3 - Hexaamino - 1λ⁵,3λ⁵-diphosphazeniumehlorid [(NH₂)₃PNP(NH₂)₃]Cl / Synthesis, Crystal Structure, and Properties of 1,1,1,3,3,3-Hexaamino- 1λ⁵ ,3λ⁵-diphosphazenium Chloride [(NH₂)₃ PNP(NH₂)₃ ]Cl

Stefan Horstmann, Wolfgang Schnick

Page range: 1732-1738

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Abstract

[(NH 2 ) 3 PNP(NH 2 ) 3 ]Cl has been prepared by a three step synthesis. The last step is the ammonolysis of [Cl 3 PNPCl 3 ]Cl. Single crystals of 1,1,1,3,3,3-hexaamino-1λ 5 , 3λ 5 -diphosphazenium chloride were obtained from an acetonitrile solution in a temperature gradient between 60 °C and room temperature. Between room temperature and -100 °C [(NH 2 ) 3 PNP(NH 2 ) 3 ]Cl is subject to a phase transition. Therefore, the crystal structure was determined by single crystal X-ray methods at room temperature (P1̄, a = 584.7(1) pm, b = 732.1(1) pm, c = 1092.0(2) pm. q = 71.05(3)°, β = 76.36(3)°, γ = 89.83(3)°, Z = 2, R = 4.75 %, wR = 2.47 %). The cation [(NH 2 ) 3 PNP(NH 2 ) 3 ] + is built up by two corner sharing PN 4 tetrahedra. Remarkably short P-N bonding distances have been observed and both PN 4 tetrahedra exhibit a significant distortion resulting in two large and four small N-P-N bond angles.

Open Access June 2, 2014

N-Iod-triphenylphosphanimin. Synthese und Kristallstrukturen von [Me₃SiNPPh₃· ICl] und Ph₃PNI / N -Iodo-triphenylphosphaneimine. Synthesis and Crystal Structures of [Me₃SiNPPh₃ · ICl] and Ph₃PNI

Jutta Grebe, Frank Weller, Kurt Dehnicke

Page range: 1739-1743

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Abstract

N-Iodo-triphenylphosphaneimine, Ph 3 PNI, has been prepared by thermolysis of the donor acceptor complex [Me 3 SiNPPh 3· ICl] in boiling acetonitrile in the presence of potassium fluoride. Both compounds have been characterized by IR spectroscopy and by crystal structure determinations. [Me 3 SiNPPh 3 · ICl]: Space group P1̄, Z = 2, a = 888.3(1), b = 1070.7( 1), c = 1310.2( 1) pm, α = 95.15( 1)°, β = 108.67( 1)°, γ = 97.78( 1)° at 20°C. The complex has a molecular structure in which the N atom of the phosphaneimine is connected with the iodine atom of the ICI molecule in a linear arrangement N-I-Cl with bond lengths N-I = 232.7 pm, I-Cl = 255.37 pm. \ Ph 3 PNI: Space group P2 1 /n, Z = 4, a = 952.8(1), b = 1800.8(2), c = 1003.6(1) pm, β = 110.25(1)° at -50°C. The compound forms monomeric molecules with bond lengths PN = 159.1 pm, I-N = 205.6 pm and an INP bond angle of 113.3°.

Open Access June 2, 2014

Zur Erzeugung von Silaethenen des Typus R₂Si=CH(SiR₃ ) und R₂Si=CH₂ durch thermische Salzeliminierung sowie zur Kenntnis von R₂Si=CH(SitBu₃) (R = Me, tBu ) / On the Generation of Silaethenes of the Types R₂Si=CH(SiR₃) and R₂Si=CH₂ by Thermal Salt Elimination and on the Knowledge of R₂Si=CH(SitBu₃) (R = Me, tBu)

Nils Wiberg, Ch. M. M. Finger, T. Passler, S. Wagner, K. Polborn

Page range: 1744-1760

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Abstract

The generation of silaethenes Me 2 Si=CH(SiMe 3 ) (1), Me 2 Si=CH(SitBu 3 ) (2), tBuMeSi=CH(SitBu 3 ) (3), and tBu 2 Si=CH 2 (4) from metal organyls >SiX-CM< (X = Br, F; M = Na, Li) by elimination of MX is investigated. The metal organyls are prepared from >SiX-CBr< and RM (R = tBu 3 Si, nBu, Ph) by Br/M exchange (for preparation of >SiX-CBr< cf. Scheme 1). Only the sterically overcrowded silaethenes 2 and 3. generated from Me 2 SiF-CHNa(SitBu 3 ) and tBuMeSiF-CHNa(SitBu 3 ), have been identified by trapping with isobutene and dimethylbutadiene under formation of ene and Diels-Alder adducts. Analogous products are not found from Me 2 SiBr-CHNa(SiMe 3 ) and tBu 2 -SiBr-CH 2 -Li. In the absence of trapping agents, compounds 1, 2, and 3 form cyclodimers. A reaction intermediate of the formation of 1 × 1 has been isolated and the structures of 2 × 2 and 3 × 3 have been solved by X-ray analysis. No dimer is observed for 4. In this case compounds are formed which may be interpreted as insertion products of 4 into the CLi bond of the precursor.

Open Access June 2, 2014

Phosphonio-substituierte Tetrahydro-1,3-diphosphinine und Tetrahydro-1,2,6-azadiphospliinine / Phosphonio-Substituted Tetrahydro-1,3-diphosphinines and Tetrahydro-1,2,6-azaphosphinines

Georg Jochem, Martin Schmidt, Heinrich Nöth, Alfred Schmidpeter

Page range: 1761-1767

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Abstract

The bis(triphenylphosphonio)propenide cation 1 provides two reactive CH sites in 1,3- position and can be condensed with the bis(dichlorophosphanyl)methylene triphenylphosphorane 2 or the bis(dichlorophosphanyl)aniline 3 to form cationic six-membered rings: A tetrahydro-1,3-diphosphinine (4) with three phosphonio or phosphoranediyl substituents in 2,4,6-position and a tetrahydro-1,2,6-azadiphosphinine (5) carrying two such substituents in 3,5-position. The bromide of the latter was used for an X-ray structure analysis. The P III ring members of the cations 4 and 5 can be oxidized in two steps by elemental sulfur to give the monothioxo and dithioxo derivatives 6. 7 and 8, 9. respectively. A crystal of the mixed chloride/bromide of 8 was used for another X-ray structure analysis.

Open Access June 2, 2014

Synthetic Epimers of Ajmaline and Isoajmaline

M. Ataullah Khan, Humaira Raees

Page range: 1768-1770

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Abstract

Two new epimers of ajmaline (1) and isoajmaline (2) were synthesized by means of tosylation followed by hydrolysis with NaOH/CH 3 OH. Displacement of tosyl with hydroxyl group yielded C 21 epimers of these alkaloids. The structures were identified by various spectroscopic techniques.

Open Access June 2, 2014

Experimental and Computational Studies on Aminoguanidine Free Base, Monocation and Dication, Part I: The Crystal and Molecular Structure of Aminoguanidine Monohydrochloride and the ab Initio Structure of the Endiamine Tautomer of Aminoguanidine Free Base

Jere T. Koskinen, Mikko Koskinen, Ilpo Mutikainen, Berit Mannfors, Hannu Elo

Page range: 1771-1778

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Abstract

The crystal and molecular structure of aminoguanidine monohydrochloride, CN 4 H 7 + .CL - in which aminonoguanidine exists in the monocation form, was determined by single-crystal X-ray diffraction. The structure of the monocation is largely similar to that of aminoguanidine dication as present in previously studied divalent salts. The monocation was found to exist in the form of the tautom er that allows strong resonance in the guanyl group. As compared to the dication, the terminal hydrazine nitrogen atom bears one hydrogen atom less. The monocation is planar, the only atoms deviating from the plane being the hydrogens attached to the terminal hydrazine nitrogen. Quantum chemical calculations on the endiamine tautomer of aminoguanidine free base as well as on aminoguanidine monocation and dication were also perform ed by using the HF and MP2 ab initio methods and also the B3- LYP and B-LYP methods based on density functional theory. On the basis of the calculations, a predicted structure of the endiamine tautom er of aminoguanidine free base is presented

Open Access June 2, 2014

Synthesis of a New bis-Harmine Selenide

M. Ataullah Khan, Humaira Raees

Page range: 1779-1780

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Abstract

Harmine ( 1) upon refluxing with selenium dioxide in acetic acid for 15 hours yielded bisharmine selenide (4) via the intermediates 2 and 3.

Open Access June 2, 2014

Regio- und Stereoselektive Ringöffnung von Epoxypyranosiden durch Isopropoxytitanreagenzien und Sml₂: Ein einfacher Zugang zu Ioddesoxyzuckern / Regio- and Stereoselective Ring Opening of Epoxy Pyranosides with Titanium Isopropoxide Reagents and Sml₂: A Straightforward Access to Iododeoxy Sugars

Noshena Khan, Yousef Al-Abed, Hans-Jürgen Kohlbau, Farzana Latif-Ansari, Wolfgang Kowollik, Wolfgang Voelter

Page range: 1781-1790

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Abstract

A regioselective synthesis of 3-iodo-3-deoxy sugars is described by trans-diaxial cleavage of the oxirane ring of 2.3-anhydropyranosides with halogenated titanium isopropoxide reagents and samarium iodide.

Open Access June 2, 2014

Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXX. 3-Hydroximino-1-alkyl(aryl)-isoindoline und 3-Hydroxylamino-1-alkyl(aryl)-1Hisoindole - Modellverbindungen für Struktur- und Reaktivitätsuntersuchungen - / Studies on the Chemistry of Isoindoles and Isoindolenines, XXXX. 3-Hydroximino-1-alkyl(aryl)-isoindolines and 3-Hydroxylamino-1-alkyl(aryl)-1Hisoindoles - Model Compounds for Investigations of Structure and Reactivity -

Andrea Clemens, Richard P. Kreher, Johannes Preut

Page range: 1791-1810

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Abstract

3-Hydroximino-isoindolines and 3-hydroxylamino-1 H-isoindoles with substituents at the five membered ring have been prepared by condensation of substituted 3-alkoxy-1 H-isoindoles with hydroxylamine and O-/N -substituted hydroxylamines. Constitution and configuration of semi-cyclic amidoximes were derived from spectroscopic investigations and deduced on the basis of orientating chemical transformations. These results have been established by a crystal structure determination of a representative 3-hydroximino-isoindoline.

Open Access June 2, 2014

Molecular Structure of Tri(2-thienyl)borane

Bernd Wrackmeyer, Wolfgang Milius, Elias Molla

Page range: 1811-1814

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Abstract

The molecular structure of tri(2-thienyl)borane (1) was determined [monoclinic, space group P2 1 / c; a = 12.216(2), b = 7.765(2), c = 12.605(2) Å, β = 93.13(2)°]; two of the three thienyl groups are disordered, as is also indicated by the solid-state 13 C CP/MAS NMR spectrum of 1. The 13 C NMR spectra of 1 were measured at variable tem perature in solution and the barrier to rotation about the B-C bonds was found to be <35 kJ/mol. Thus, CB(pp)π interactions must be regarded as rather weak, in spite of suggestive δ 11 B. δ 13 C data and structural parameters.

Open Access June 2, 2014

On the Preparation of 5-(α-DiazoethyI)tetrazoles

Dietrich Moderhack, Andreas Beißner

Page range: 1815-1818

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Abstract

Hydrazone dehydrogenation with silver(I) oxide in the presence of sodium hydroxide was found an efficient approach to the title compounds, whereas application of the Bamford-Stevens reaction proved unsatisfactory.

Open Access June 2, 2014

Subject Index

Page range: 1819-1854

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Open Access June 2, 2014

Authors Index

Page range: 1855-1858

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About this journal

Objective
Zeitschrift fuer Naturforschung B (ZNB) publishes novel research in all areas of inorganic chemistry, organic chemistry, and analytical chemistry. In particular, the journal focuses on solid state chemistry, coordination chemistry, main group element chemistry, synthetic organic chemistry, natural product chemistry and, to a lesser extent, on analytical chemistry. For more than 65 years Zeitschrift fuer Naturforschung B has been open to contributions from all fields of experimental and theoretical chemistry. Zeitschrift fuer Naturforschung B publishes 12 issues per volume/year. Sometimes double issues occur.

Topics

Solid state chemistry
Coordination chemistry
Main group element chemistry
Organic chemistry
Natural product chemistry

Article formats
Original (full) papers, research notes and preliminary communications, reports on specific research topics of current interest (reviews)

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Volume 51 Issue 12

Issue of Zeitschrift für Naturforschung B

Gold(I) Complexes of Chiral Secondary Phosphines

Abstract

Ein zweikerniger Vanadium(V)-Komplex mit (μ1)- und (μ-μ2:μ2)-gebundenen Hydrazido(2-)-Liganden / A Dinuclear Vanadium(V) Com plex with (μ1)- and (μ-μ2:μ2)-Bonded Hydrazido(2-) Ligands

Abstract

Synthesis and Characterization of Bis(3-chloro-4-dodecyloxyphenyl) Malondialdehyde Complexes of Cu(II) and Ni(II)

Abstract

Asymmetrie Ethynes. Syntheses of Ethynylferrocene Paradigms

Abstract

Untersuchungen zur Säurestärke von Alkanpolysulfonsäuren / Investigations on the Acid-Strength of Alkanepolysulfonic Acids

Abstract

Metallkomplexe mit Cyanoguanidin als Liganden: Kristallstrukturen von [Cd(cnge)2F2]·3H2O , Cd(cnge)2Br2 und Hg(cnge)Cl2 (enge = C yanoguanidin) / Metal Complexes with Cyanoguanidine as Ligand: Crystal Structures of [Cd(cnge)2F2]·3H2O, Cd(cnge)2Br2 and Hg(cnge)Cl2 (cnge = Cyanoguanidine)

Abstract

Reaction of Borane in Tetrahydrofuran with 1,1,3,3-Tetramethyldisilazane and Cyclic Disilazanes - Competition Between N-Si and N-H Bond Cleavage

Abstract

Heterometallische Mehrkernkomplexe von Zink und Cadmium mit cis-[Cr(OH)2(en)2]+-Liganden / Heterom etallic Polynuclear Complexes of Zinc and Cadmium with cis-[Cr(OH)2(en)2]+ Ligands

Abstract

Ein neuer Heterocyclus, 2λ3,4λ5-[1,2,4]-Oxadiphosphinin (2), als Ligand eines zweikernigen Eisenkomplexes / A New Heterocycle, 2λ3, 4λ5 -[1,2,4]-Oxadiphosphinine (2), as Ligand of a Binuclear Iron Complex

Abstract

Synthese, Kristallstruktur und Eigenschaften von 1,1,1,3,3, 3 - Hexaamino - 1λ5,3λ5-diphosphazeniumehlorid [(NH2)3PNP(NH2)3]Cl / Synthesis, Crystal Structure, and Properties of 1,1,1,3,3,3-Hexaamino- 1λ5 ,3λ5-diphosphazenium Chloride [(NH2)3 PNP(NH2)3 ]Cl

Abstract

N-Iod-triphenylphosphanimin. Synthese und Kristallstrukturen von [Me3SiNPPh3· ICl] und Ph3PNI / N -Iodo-triphenylphosphaneimine. Synthesis and Crystal Structures of [Me3SiNPPh3 · ICl] and Ph3PNI

Abstract

Abstract

Phosphonio-substituierte Tetrahydro-1,3-diphosphinine und Tetrahydro-1,2,6-azadiphospliinine / Phosphonio-Substituted Tetrahydro-1,3-diphosphinines and Tetrahydro-1,2,6-azaphosphinines

Abstract

Synthetic Epimers of Ajmaline and Isoajmaline

Abstract

Experimental and Computational Studies on Aminoguanidine Free Base, Monocation and Dication, Part I: The Crystal and Molecular Structure of Aminoguanidine Monohydrochloride and the ab Initio Structure of the Endiamine Tautomer of Aminoguanidine Free Base

Abstract

Synthesis of a New bis-Harmine Selenide

Abstract

Regio- und Stereoselektive Ringöffnung von Epoxypyranosiden durch Isopropoxytitanreagenzien und Sml2: Ein einfacher Zugang zu Ioddesoxyzuckern / Regio- and Stereoselective Ring Opening of Epoxy Pyranosides with Titanium Isopropoxide Reagents and Sml2: A Straightforward Access to Iododeoxy Sugars

Abstract

Abstract

Molecular Structure of Tri(2-thienyl)borane

Abstract

On the Preparation of 5-(α-DiazoethyI)tetrazoles

Abstract

Subject Index

Authors Index

Ein zweikerniger Vanadium(V)-Komplex mit (μ¹)- und (μ-μ²:μ²)-gebundenen Hydrazido(2-)-Liganden / A Dinuclear Vanadium(V) Com plex with (μ¹)- and (μ-μ²:μ²)-Bonded Hydrazido(2-) Ligands

Heterometallische Mehrkernkomplexe von Zink und Cadmium mit cis-[Cr(OH)₂(en)₂]⁺-Liganden / Heterom etallic Polynuclear Complexes of Zinc and Cadmium with cis-[Cr(OH)₂(en)₂]⁺ Ligands

Ein neuer Heterocyclus, 2λ³,4λ⁵-[1,2,4]-Oxadiphosphinin (2), als Ligand eines zweikernigen Eisenkomplexes / A New Heterocycle, 2λ³, 4λ⁵ -[1,2,4]-Oxadiphosphinine (2), as Ligand of a Binuclear Iron Complex

Synthese, Kristallstruktur und Eigenschaften von 1,1,1,3,3, 3 - Hexaamino - 1λ⁵,3λ⁵-diphosphazeniumehlorid [(NH₂)₃PNP(NH₂)₃]Cl / Synthesis, Crystal Structure, and Properties of 1,1,1,3,3,3-Hexaamino- 1λ⁵ ,3λ⁵-diphosphazenium Chloride [(NH₂)₃ PNP(NH₂)₃ ]Cl

N-Iod-triphenylphosphanimin. Synthese und Kristallstrukturen von [Me₃SiNPPh₃· ICl] und Ph₃PNI / N -Iodo-triphenylphosphaneimine. Synthesis and Crystal Structures of [Me₃SiNPPh₃ · ICl] and Ph₃PNI