bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyacrylamid-Elektrophorese zur Beurteilung von Proteinen der Kartoffel (Solanum tuberosum L.)
Authors: Loeschcke Volkmar , Stegemann Hermann
Published: February 2015

Up to 25 proteins have been found in the sap of potato tubers by polyacrylamid electrophoresis. The mode of preparation and concentration of the plant material was investigated as well as the pretreatment of the polyacrylamid gel to avoid undue retardation of the migrating bands.

Sulfite was the most active inhibitor of sap-browning compared with ascorbic acid and cysteine. which did not influence the protein pattern except for one line. The juice had to be dialyzed or filtered through Sephadex G 25 to remove an unkown acidic material which interferes with the more acidic proteins and causes spreading and diffusing of bands. Proteins were concentrated by means of Carbowax MW 20000. For best results ionic contaminations inherent in the gels was removed by electrophoresis before applying the proteins or dyes. Very few proteins were affected by decreasing the pore size of the gel. Ammonium sulfate (40% saturation) precipitated mainly those proteins which are similar in electrophoretic behavior to the albumin- and transferrinregion of human plasma.
Die Inhaltsstoffe von Lecanora viridula (FLK.) HILLM., Lecanora polytropa (EHRH.) RABENH., Lecanora badia (HOFFM.) ACH. v. milvina RABENH. und Lecanora sulphurea (HOFFM.) ACH.
Authors: Huneck Siegfried
Published: February 2015

Es wird die Isolierung und Charakterisierung von Inhaltsstoffen aus vier Lecanoraceen beschrieben. L. viridula (FLK.) HILLM. enthält Aspicilin, L. polytropa (EHRH.) RABENH. Zeorin, das neue Triterpen Eulecanorol, ( + )-Usninsäure und Rangiformsäure, L. badia (HOFFM.) ACH. v. milvina RABENH. Lobarsäure und (+)-Usninsäure und L. sulphurea (HOFFM.) ACH. Zeorin und ( + )-Usninsäure.
The Nature of Electrode Processes of Guanine and its Derivatives
Authors: Janik B. , Paleček E.
Published: February 2015

At negative potentials in the region of background electrolyte decomposition, a product arises on the mercury electrode in solutions of guanine and its derivatives. The product is probably in its reduced form. An oxidation of this product is responsible for the origin of anodic identification on oscillograms of dE/dt against E or of anodic polarographic waves.
Zur Umsetzung von Malonimiden mit Grignard- Verbindungen
Authors: Flitsch W. , Heidhues R.
Published: February 2015

Malonimide reagieren mit Grignard - Verbindungen zu Amiden und tert. Carbinolen. Die Struktur der Reaktionsprodukte gestattet zusammen mit Versuchen, die unter anderem zur Isolierung von Zwischenprodukten führen, die Aufstellung eines Reaktionsschemas.
Zur Struktur eines Bi-pyridon-yls
Authors: Junek H. , Sterk H. , Schmidt A.
Published: February 2015

Dimeres Malonsäuredinitril reagiert in Eisessig mit 1-Methylamino-3-phenyl-propen- (1) -on (3) zu einer gelb gefärbten Verbindung. Mit Hilfe der Infrarot-, Massen- und Protonenresonanz-Spektren wird derselben die Struktur eines 3.3′-Cyan-4.4′-phenyl-6.6′-bi-pyridon- (2.2′) -yl zugeschrieben.
N, O-Acylwanderung bei Cobinamid - Gewinnung von Cobyrsäure aus Cobamiden
Authors: Müller Gerhard , Müller Otto
Published: February 2015

Bei der Behandlung von Cobinamid mit Flußsäure/Methanol/Zinkchlorid oder Zinkchlorid/Methanol erfolgt an der Carbonsäureamidgruppe f N,O-Acylwanderung zum Cobyrsäure- [β-aminoiso-propylester], der nach Acylierung der Aminogruppe mit Piperidin/Wasser zu Cobyrsäure hydrolysiert wird. Cobamide werden unter den Bedingungen der Umlagerung zu Cobinamid abgebaut, so daß sie ebenfalls zur Gewinnung des Esters dienen können.

Cobyrsäure- [β-aminoisopropylester] unterliegt in basischem Medium der O,N-Acylwanderung, wobei Cobinamid zurückgebildet wird. Durch Umsetzung mit salpetriger Säure erhält man aus Cobyrsäure- [β-aminoisopropylester] den Cobyrsäure- [β-hydroxyisopropylester]. In wasserfreier Flußsäure wird Cobinamid durch Essigsäureanhydrid, Buttersäureanhydrid und Benzoylchlorid in die entsprechenden O-Acyl-Derivate übergeführt.
Unbeeinflußbarkeit ihrer Wirkung auf Ribonuclease durch Cystamin und tiefe Temperaturen
Authors: Jung H.
Published: February 2015

Slow protons having energies below 1.5 keV dissipate their kinetic energy in matter through elastic nuclear collisions. By this process atoms are displaced out from their original positions in macromolecules. This was recently shown to cause biological damage with high efficiency. Experiments are described to test the possibility of modifying the sensitivity of ribonuclease towards elastic collisions by protective agents and by low temperatures. When cystamine is present during irradiation dry ribonuclease is protected against the action of “ionizing” fast protons (2 MeV), the dose reduction factor being 1.8. But no protection is observed when inactivation is achieved by elastic nuclear collisions (proton energy 1 keV and 1.4 keV). Similar results were obtained when the irradiations were carried out at different temperatures. Using 2 MeV protons the radiosensitivity of ribonuclease was found to be 3 times higher at room temperature than at 125 °K, but when using slow protons of 1.4 keV energy the inactivation cross section turned out to be independent of temperature. This shows that the action of elastic nuclear collisions can be modified neither by cystamine nor by low temperatures.
Arylazoisoxazolinthiones: Preparation and Reactions of 4-Arylazo-3-methyl-2-isoxazolin-5-thiones
Authors: Kassab Nazmi A. , Allah Sanaa. O. Abd , Elbahati Said A.
Published: February 2015

The arylazo derivatives (2) of 3-methyl-2-isoxazolin-5-thione were prepared. Alkylation of 2 with alkyl halides results in the formation of the S-alkyl derivatives (5). The S-acetate esters undergo thermal isomerisation to the corresponding 1,2,3-triazole derivatives (6). The thiones 2 condense with hydrazines and primary amines to afford the corresponding 5-hydrazones and 5-imines (8) and (10), respectively. Treatment of 2 with hydrazine hydrate and Phenylhydrazine in boiling alcohol effects ring cleavage with the formation of 9.
Zur Chemie des Kohlensubsulfids, III1 Formation of Pyrimidinthiones / Chemistry of Carbon Subsulphide, III1 Formation of Pyrimidinthiones
Authors: Stadlbauer Wolfgang , Kappe Thomas , Ziegler Erich
Published: February 2015

Carbon Subsulphide, 2-Aminopyridine, N-Phenylbenzamidine, ß-Aminocrotonate Carbon subsulphide, C3S2, reacts with 2-aminopyridine (la) and N-phenylbenzamidine (lb) to yield the corresponding higher condensed derivatives 4 and 7. Attempts to obtain mesoionic compounds by reaction of N-substituted 2-aminopyridines or N,N'-disubsti-tuted benzamidines were not successful. Efforts to yield a pyridinethione derivative by reaction of C3S2 with /?-aminocrotonate (lc) failed. In this case the sulphur-bridged compound 8 could be isolated.
1.4-Dioxan · H2O · SbCl5; Schwingungsspektren, Kristall- und Molekülstruktur / 1,4-Dioxane · H2O · SbCl5; Vibrational Spectra, Crystal and Molecular Structure
Authors: Schwarz W. , Schmidt A. , Binder G. E.
Published: February 2015

The preparation of the 1:1:1 addition compound 1 of 1,4-dioxane, water and antimony(V) chloride is described. 1 crystallizes in the space group Cmcm with the lattice constants a = 8.494, b = 11.453, c = 13.030 Å with four formula units in the unit cell. The dioxane is strongly hydrogen bonded to an antimony(V) chloride water adduct. The vibrational spectra of the solid are assigned
Zur Struktur der Verbindungen BaZn2P2 und BaZn2As2 / The Crystal Structure of BaZn2P2 and BaZn2As2
Authors: Klüfers Peter , Mewis Albrecht
Published: February 2015

New AB2X2--compounds, BaZn2P2 and BaZn2As2, were prepared. The structures were determined by X-ray methods. In the case of BaZn2P2 (S.G. I4/mmm; a = 4.019 Å, c = 13.228 Å) layers of edgeshared ZnP4-tetrahedra alternate with Ba-layers; in the case of BaZn2As2 (S.G. Pnma; a = 10.010 Å, b = 4.246 Å, c = 10.910 Å) Zn and As build a 3D-network of edge and vertex shared tetrahedra with Ba in the holes of this network
Über die Perhydrolyse von Tris(alkoxy)boranen in Gegenwart einiger anorganischer und organischer Basen in nichtwäßrigen Lösungsmitteln / On the Perhydrolysis of Tris(alkoxy)boranes in the Presence of Some Inorganic and Organic Bases in Nonaqueous Solvents
Authors: Heller Gert , Marquard Dirk
Published: February 2015

Perhydrolysis of various tris(alkoxy)boranes B(OR)3 with R = CH3, n-C3H7, tert-C4H9 or n-C8H17 in the presence of lithium alkoxides LiOR′ where R′ = CH3, C2H5, n-C4H9 or tert-C4H9, or in the presence of RbO-n-C4H9, tert-butylamine or cyclohexylamine in alcoholic media other than methyl alcohol yields with H2O2/H2O (85:15 by weight) the peroxoborates LiBO3,7 · H2O, RbBO4 · 0,5 H2O, tert-C4H9NH3BO4 · 0,5 H2O or cyclo- C6H11NH3BO4 · H2O, with H2O2/H2O (98:2 by weight) LiBO3,8 - H2O, RbBO4,7 · H2O, tert-C4H9NH3BO5 · H2O or cyclo-C6H11NH3BO4,8 · H2O.

H2O2/H2O (98:2 by weight) was prepared by a modified method.

With reference to stabilities, IR spectra and NMR spectra, the structures of these noncrystalline polyborates are discussed. All the compounds contain the active oxygen in the form of B-O-O-groups
Selenium Heterocycles, III [1]. Synthesis of Selenolo(2,3-b)quinolines
Authors: Raja T. K. , Soundararajan N. , Bakthavachalam V. , Shanmugam P.
Published: February 2015

The synthesis of selenolo(2,3-b)quinolines is described starting from 2-chloro-3-(1′,2′- dibromoethyl) quinolines
Synthese von Tri-tert-butylstibin und Tetra-tert-butylcyclotetrastiban durch Reaktion von Di-tert-butylantimonchlorid mit Magnesium / Synthesis of Tri-tert-butylstibine and Tetra-tert-butylcyclotetrastibane by Reaction of Di-tert-butylantimonychloride with Magnesium
Authors: Breunig Hans Joachim
Published: February 2015

Di-tert-butylantimonychloride reacts with magnesium to tri-tert-butylstibine and tetra-tert-butylcyclotetrastibane
Synthese von Tetrakis(trimethylgermyl)- distiban / Synthesis of Tetrakis (trimethylgermyl)- distibane
Authors: Breunig Hans Joachim
Published: February 2015

Tris(trimethylgermyl)stibine reacts with alkylhalides with formation of tetrakis (trimethylgermyl)distibane
Zinn-Chalkogenheterocyclen, VIII [1]. Dimethylzinntellurid, ein Sechsring / Tin-Chalcogen Heterocycles, VIII [1]. Dimethyltin Telluride, a Six-membered Ring
Authors: Blecher Axel , Mathiasch Bernd
Published: February 2015

The first tin-tellurium six-membered ring, tris(dimethyltin telluride) is obtained by the reaction of dimethylstannane with tellurium. The trimeric character of this compound is proved by molecular weight determination and mass spectral data. Additional vibrational data are given
Über die Strukturen der CuZrF6-Modifikationen - Neutronenbeugungsuntersuchungen an den Kristallpulvern / A Neutron Diffraction Study on the Modifications of CuZrF6
Authors: Propach V. , Steffens F.
Published: February 2015

The structures of two modifications of CuZrF6 by means of neutron diffraction on powder samples in the temperature range from 298-560 K are reported. All modifications consist of octahedra, which share corners in three dimensions and which are centered alternately by Cu2+ or Zr4+. The high temperature α-modification crystallizes in space group Fm3 (No. 202) with α = 7.939 Å. There is experimental evidence, that the CuFe-octahedra are distorted by a static Jahn-Teller-effect. The space group P1̄ (No. 2) with Z = 2 is proposed for the low-temperature γ-modification.
Chalkogenide des As, Sb und Bi als positive Elektroden in Lithium-Batterien / Chalcogenides of As, Sb and Bi as Positive Electrodes in Lithium Cells
Authors: Besenhard Jürgen O.
Published: February 2015

Redox properties of layer type chalcogenides of main group V elements were investigated in molten salt and organic Li+-electrolytes. Even at room temperature, Bi2S3, Bi2Se3 and Bi2Te3 can be reduced with about 100% material efficiency to Li3Bi as final product. The reduction of Bi2S3 to Bi0 and Li2S can be reversed in organic electrolytes.
P-funktionell verbrückte Mangancarbonylkomplexe P-Functionally Bridged Manganese Carbonyl Complexes
Authors: Schäfer Hans
Published: February 2015

Mn(CO)5Br and (Me3Si)3P react to give Mn2(CO)8 (μBr) (μP(SiMe3)2) 3. Using methanol, both Si-P bonds of 3 can be cleaved, forming Mn2(CO)8 (μBr) (μPH2) 4. On dissolving 4 in CCl4 a P-H, C-Cl̲ exchange reaction is observed, yielding Mn2(CO)8 (μBr) (μPCl2). IR and NMR data are reported.
Darstellung und Charakterisiening der Spezies R-C7H7Mo(CO)3 und die Röntgenstrukturanalyse von / Synthesis and Characterisation of the Species R-C7H7Mo(CO)3 and the X-ray Structure Determination of
Authors: Sommer Margret , Weidenhammer Klaus , Wienand Henning , Ziegler Manfred L.
Published: February 2015

The species R−C7H7Mo(CO)3 (R=−CH2COCH3,−CH(CH3)COCH3,−CH(CH)(CH3)2COCH3) have been synthesized by electrolysing [η7-C7H7Mo(CO)3]+, η7-C7H7Mo(CO)2Br and the dimers [C7H7Mo(CO)3]2 and (C7H7)2Mo(CO)3, respectively, in suitable ketones and HBr. 1H NMR spectra and the X-ray structure determination of (CH3−CO−CH(CH3)−C7H7)Mo(CO)3 revealed the CH3−CO−CH(CH3)-group being bonded to the cycloheptatriene ligand via the α-carbon atom of the ethyl group.
Sila-Pharmaka, 9. Mitt. [1] Darstellung und Eigenschaften potentiell curarewirksamer Silicium-Verbindungen, I / Sila-Drugs, 9th Communication [1] Preparation and Properties of Silicon Compounds with Potential Curare-Like Activity, I
Authors: Tacke Reinhold , Niedner Roland
Published: February 2015

Organosilicon compounds 8, 9 and 10 with potential curare-like action and their precursors 5, 6 and 7 were synthesized for the first time. 5−10 were characterized by their physical and chemical properties, and their structures were confirmed by analyses, 1 H NMR and mass spectroscopy (only for 5−7). The pharmacological and toxicological data of 8, 9 and 10 are reported.
Aromatische Photosubstitutionsreaktionen halogenierter Benzoesäurebenzylester [1] / Aromatic Photosubstitution Reactions of Halogenated Benzoic Acid Benzylesters [lj
Authors: Bak Claudia , Praefcke Klaus
Published: February 2015

A photorearrangement of the benzylester of benzoic acid in ethanol as discribed under formation of 2-benzyl-resp. 4-benzylbenzoic acid does not occur. In dependence of irradiation time and used UV lamp the only definate product found is benzoic acid in different yields (5-21%). On irradiation through Pyrex or Solidex filter glass the benzylester does not react. Benzylesters of 2-halogenated resp. 2,4-or 2,6-dichlorated benzoic acids undergo a photosubstitution of halogens in 2-position against hydrogen or phenyl from the solvent ethanol or benzene resp. A photochemical cleavage of the C-Cl-bond in 4-position as well as a substitution of halogens against benzyl under formation of 2-benzyl-or 4-benzyl-benzoic acids are not observed. But in some cases benzoic acid or benzylhalides are isolated.
Novel Aspects in the Preparation of Phorone
Authors: Konieczny Maria , Sosnovsky George
Published: February 2015

The condensation of acetone using anhydrous hydrogen chloride results after three weeks at room temperature, in a 15% yield of phorone (4) and a 75% yield of mesityl oxide (5). In the presence of one weight percent of the Lewis acid, aluminium chloride, the yield of 4 is increased to 39%. An increase in the amount of the Lewis acid, aluminium chloride, to ten weight percent results in a 22% yield of phorone (4) and a 68% yield of mesityl oxide (5). In the presence of one hundred weight percent of aluminium chloride,

in the absence of hydrogen chloride, the condensation produces a 62% yield of mesityl oxide (5) and no phorone (4). In the course of this investigation, two intermediates, 6 and 7

were isolated and characterized for the first time. These intermediates are the actual products formed in the condensation of acetone with hydrogen chloride, and not the “free” phorone (4) and mesityl oxide (5). The conversion of 6 and 7 to 5 and 4, respectively, occurs during the isolation stage using a saturated solution of ethanolic potassium hydroxide.
ε-In2S3, eine Hochdruckmodifikation mit Korundstruktur / ε-In2S3, a High Pressure Modification with Corundum Type Structure
Authors: Range Klaus-Jürgen , Zabel Manfred
Published: February 2015

A quenchable high pressure modification of In2S3 was prepared at 35kbar and 500 °C. ε-In2S3 (Space group R3̅c, a = 656,1 pm, c = 1757.0 pm, Z = 6) is isotypic with Lu2S3 (Corundum type structure).
Darstellung und Struktur von (Di)kalium[sulfeno-thioxoacetat (2-)], K2[O2C−C(S)SO] · H2O, dem Salz einer gemischten 0. S-Persäure / Preparation and Structure of Dipotassium Sulfeno-thioxo-acetate( 2-), K2[O2C−C(S)SO] · H2O, the Salt of a Mixed O,S-Peracid
Authors: Bielak Siegfried , Mennemann Karl , Mattes Rainer
Published: February 2015

The structure of K2[O2CC(S)SO] · H2O, an oxidation product of 1,1-dithio-oxalate, has been determined by X-ray crystallography. The orthorhombic unit cell of the disordered struc­ture contains only one formula unit. The di­negative anion is planar; it may be considered as a peroxothioacid anion.
Stereochemie der Metall-Metall-Bindung: Darstellung und Struktur von Co2(CO)4C5H5P(CH3)2 / Stereochemistry of the Metal-Metal Bond: Preparation and Structure of Co2(CO)4C5H5P(CH3)2
Authors: Keller Egbert , Vahrenkamp Heinrich
Published: February 2015

The title complex 4 was prepared from η-C3H5Co(CO)3 and η-C5H5(CO)Co-P(CH3)2H. It completes the series of PR2-and AsR2-bridged homodinuclear complexes C2(CO)7C5H5-As(CH3)2, Mn2(CO)6C5H5As(CH3)2, and Fe2(CO)5C5H5P(CH3)2. Its crystal structure analysis reveals the systematic variation of the ligand distribution along the series which depends only on the number of ligands present and not on given coordination geometries. The metal-metal bond length in 4 is mainly determined by the stereochemical require-ments of the bridging phosphido ligand.
AB2X2-Verbindungen im CaAl2Si2-Typ, V[1] Zur Struktur der Verbindungen CaMn2P2, CaMn2As2, SrMn2P2 und SrMn2As2 / AB2X2-Compounds with the CaAl2Si2 Structure, V [1] The Crystal Structure of CaMn2P2, CaMn2As2, SrMn2P2, and SrMn2As2
Authors: Mewis Albrecht
Published: February 2015

Four ternary compounds with the formulas CaMn2P2, CaMn2As2, SrMn2P2, and SrMn2As2 have been prepared and investigated by X-ray methods. They are isotypic and crystallize trigonally in a CaAl2Si2-type structure (space group P3̅m 1-D3
3d) with the lattice constants:

CaMn2P2 a = 4,096 ± 0,001 Å, c = 6,848 ± 0,002 Å,

CaMn2As2 a = 4,239 ± 0,001 Å, c = 7,027 ± 0,003 Å,

SrMn2P2 a = 4,168 ± 0,001 Å, c = 7,132 ± 0,001 Å,

SrMn2As2 a = 4,306 ± 0,001 Å, c = 7,315 ± 0,001 Å.

The lattice constants of BaMn2P2 and BaMn2As2 are given
Zur Synthese von N-(Chlormethyl)carbimidoylchloriden / Synthesis of N-(Chloromethyl)carboximidoyl Chlorides
Authors: Böhme Horst , Ahrens Kurt Henning , Drechsler Hans-Joachim , Rumbaur Georg
Published: February 2015

From N-(hydroxymethyl)- and N-(chloromethyl)carboxylic acid amides (3) and (4) respectively by treatment with 2 or 1 mol phosphorus pentachloride respectively N- (chloromethyl)carboximidoyl chlorides (10) are formed. As side products in addition to acyl chloride (6) and carbonitrile (14) can be isolated tris(chloromethyl)amine (7), N- (chloromethyl)carboximidic acid chloromethylester (15), N-bis(chloromethyl)phosphoramidic dichloride (11) and l,3-bis(chloromethyl)-2,2,2,4,4,4-hexachloro-2,2,4,4-tetrahydro- l,3,2,4-diazadiphosphetidin (12)
Die Kristallstruktur von β-NaSbS2 / The Crystal Structure of β-NaSbS2
Authors: Volk Klaus , Schäfer Herbert
Published: February 2015

β-NaSbS2 crystallizes monoclinically, C2/m, with a = 1284(2) pm, b = 582.5(8) pm, c = 581.3(3) pm, β - 118.74(7)°. In the structure there are ψ-SbS5-octahedra, which are connected by common edges to sheets separated by the Na ions.
The Crystal and Molecular Structure of (Pentane-2,4-dionato)-tetrafluorophorane
Authors: Sheldrick W. S. , Hewson M. J. C.
Published: February 2015

(Pentane-2,4-dionato)-tetrafluorophosphorane crystallises in the space group P21/c, Z = 8, with a = 8.896(2), b = 13.760(4), c = 13.316(2) Å, β = 93.42(3)°. The structure was refined to R = 0.053 for 2445 reflections. Small but significant differences are observed in the bond angles at phosphorus and in the chelate ring conformations of the two indepen­dent molecules. These display an approximate mirror plane perpendicular to the chelate rings, which are in the boat form with P and C(3) displaced from the plane of the remaining ring atoms. The average P-O distance of 1.719(2) Å is similar to that for a σ-bond. 19F and 31P NMR and mass spectral data are reported. The basis peak is formed by the cleavage of the two P-0 bonds resulting in the ion PF4+ (m/e 107).
Die Cyanat-induzierte Umwandlung von Calciumhydrogenphosphat in Calciumdiphosphat -eine präbiotische Schlüsselreaktion ? / The Conversion of Calcium Hydrogenphosphate into Calcium Diphosphate by Cyanate - a Prebiotic Key Reaction ?
Authors: Seel F. , Schinnerling F.
Published: February 2015

The conversion of calcium phosphate into calcium diphosphate through cyanate in an aqueous suspension, discovered by Miller and Parris [1], has been reinvestigated thor-oughly. The reaction is initiated through the disproportionation of calcium hydrogen phosphate to give hydroxylapatite and calcium dihydrogen phosphate, which reacts with cyanate via carbamoylphosphate to yield calcium diphosphate and urea. In particular, it could be shown that the process of phosphate condensation may also be initiated when cyanate is generated by a photochemical oxidation of hydrocyanic acid. -The importance of this reaction with respect to the prebiotic synthesis of biopolymers is discussed.
The Isolation and Characterization of Square Planar, Square Pyramidal, and Octahedral Copper(II) Complexes with Mixed Ligands
Authors: Aly M. M.
Published: February 2015

Substitution of an acetylacetonate by a carboxylate in the neutral (acac)2Cu(II) was achieved by its reaction with tri- and dichloroacetic acid in benzene (HCO2R where R = CCl3 or CHCl2; Hacac = acetylacctone) which led to the formation of the mixed chelate square planar complex (acac)Cu(OCOR). The later complex, R = CCl3, reacted with heterocyclic bases to produce the square pyramidal complexes (acac)Cu(OCOR) (base), (base = 2- methylpyridine or quinoline); with ethylenediamine (en) to give the octahedral [(en)2Cu(OCOR)]Cl, and with methanol and piperidine or boiling methanol alone to give the methoxo-bridged (acac)Cu(OCH3)2Cu(acac). The reaction of acetylacetonate-carboxy- late-copper(II) complex (R = CHCl2) with heterocyclic bases led to the cleavage of the acetylacetonate ligand and the formation of the octahedral Cu(OCOCHCl2) · 2 base (base = pyridine, 2-, 3- or 4-methylpyridine). The same cleavage reaction took place, and also with R = CCl3, in their reaction with 8-hydroxyquinoline to form the mixed chelates (ROCO)Cu(Oxinate). These formulations are based on chemical analyses, electronic and vibrational spectra, and on conductance measurements.
NOTIZEN: Ein neues Darstellungsverfahren von Carbo- und Schwefeldiimiden / A New Method for the Preparation of Carbo- and Sulfurdiimides
Authors: Klingebiel Uwe
Published: February 2015

In the reaction of lithio-aminofluorosilanes with trimethylsilylisocyanate or trimethylsilylthionylimide LiF is eliminated and carbodiimides and sulfurdiimides are formed, respectively.
Eine einfache Methode zur Darstellung von wasserfreien Natrium-dithiocarboxylaten / A Convenient Preparation Method of Anhydrous Sodium Dithiocarboxylates
Authors: Kato Shinzi , Ito Khoji , Hattori Rikizo , Mizuta Masateru , Katada Tomonori
Published: February 2015

It has been found that anhydrous sodium dithiocarboxylates are readily obtained by the reaction of dithiocarboxylic acid with sodium metal or sodium hydride.
Über das Verhalten von 5-Hydroxy-Kawainen gegen Alkali / Behaviour of 5-Hydroxykawain Derivatives under Mild Alkaline Conditions
Authors: Hansel R. , Pelter A. , Ayoub M. T. , Reinhardt R.
Published: February 2015

Treatment of cis-dihydroxykawainol = rel (5R, 6R)-(±)-5-hydroxy-4-methoxy-6- phenylethyl-5,6-dihydro-2H-pyran-2-on (cis-3) with potassium hydroxide in methanol (2.5%, 1 h, room temp.) leads to a 1:1 mixture of the corresponding erythro-butenolide 7 and threo-butenolide 8 by a ring contraction process that may have analogies with the biosynthesis of the piperolides 15. Trans-3 gives the same yields (about 70%) of the same mixture (7 and S), which can be separated by silica-gel columns. Starting from mixtures of cis-5-hydroxykawain (cis-4) and trans-5-hydroxykawain (trans-4), there were prepared and described the two epimeric dehydro-butenolides 9 and 10 and their O-methylderivatives 11 and 12. The threo- and erythro-series show consistant differences between J5,6 and the 1H NMR spectra. The constitution and configuration of (± )-erythro-5- (1-methoxy-3-phenylallyl)-4-methoxy-2(5H)-furanone (11) were established by X-ray analysis.
Structure of 4-Arylazo-3-methylisoxazol-5- thiones
Authors: Summers Lindsay A.
Published: February 2015

Contrary to a recent report, 4-arylazo-3- methylisoxazol-5-thiones exist predominately as the 3 -methyl - 4-arylhydrazono-isoxazol- 5-thione tautomer.
NMR-Spektroskopie an paramagnetischen Komplexen, XIX 13C-und 1H-NMR-Zugang zu gewinkelten Titanocenen/NMR Spectroscopy on Paramagnetic Complexes, XIX 13C and 1H NMR Access to Bent Titanocenes
Authors: Köhler Frank H. , Cozak Daniel
Published: February 2015

From [(RC5H4)2TiCl]2, R = H (1), CH3 (2) and C2H5 (3), (C5H5)2TiBH4 (4) and (C5H5)2Ti(CH3CN)Cl (5) the first paramagnetic 13C and 1H NMR spectra in the series of bent titanocenes have been obtained. Broad signals shifted to low field originate from the cyclopentadienyl protons while the corresponding 13C signals appear at high field relative to a diamagnetic reference. This is ascribed to π-polarisation which dominates the transfer of unpaired electrons onto the five-membered ring while σ-polarisation delocalizes them onto other ligands. The NMR shifts indicate that titanocene halides are antiferromagnetically coupled in solution, the extent depending on the solvent and on five-membered ring substituents. In the gas phase only monomers are found by mass spectroscopy. Paramagnetic NMR further reveals proton exchange in 4 and ligand dissociation in 5.
Über neue zweikernige Metallcarbonylkomplexe mit Cyclohexadienyl-cycloheptatrien-und Cyclohexadienyl-isonitril-Brücken/On New Dinuclear Metal Carbonyl Complexes with Cyclohexadienyl Cycloheptatriene and Cyclohexadienyl Isonitrile Bridges
Authors: Moll Matthias , Würstl Peter , Behrens Helmut , Merbach Peter
Published: February 2015

The reactions of the electrophilic [C6H7Fe(CO)3]+ -and [C6H7Fe(CO)2CNEt]+-cations with theextremely nucleophilic [C7H7Fe(CO)3]- -anion lead to the formation of the dinuclear cyclohexadienyl cycloheptatriene bridged complexes (OC)3FeC6H7-C7H7Fe(CO)3 and EtNC(OC)2FeC6H7-C7H7Fe(CO)3. In a similar reaction the tricarbonyl cation [CeH7Fe(CO)3]+ with [Cr(CO)5CN] _ yields the dinuclear cyclohexadienyl isonitrile bridged compound (OC)3FeC6H7-NCCr(CO)5. The mass, IR and NMR data of the new complexes are reported.
Chemie polyfunktioneller Liganden, 48 [1]. Synthese, Schwingungsspektren, Molekül-und Kristallstruktur eines Organocyclotriarsan-pentacarbonylchrom-Komplexes / Chemistry of Polyfunctional Ligands, 48 [1]. Synthesis, Vibrational Spectra, Molecular and Crystal Structure of an Organocyclotriarsane-pentacarbonylchromium Complex
Authors: Ellermann Jochen , Lindner Helmut A. , Schössner Horst , Thiele Gerhard , Zoubek Gerd
Published: February 2015

The organocyclotriarsane, CH3C(CH2As)3 (1), reacts with chromium hexacarbonyl on ultraviolet irradiation to give the complex CH3C(CH2As)3Cr(CO)5 (2), in which the cyclo-triarsane is behaving as a monodentate ligand. The crystal structure of 2 has been determinated by X-ray diffraction. The monoclinic unit cell (space group P21/n) contains 4 isolated molecules in a hexagonal closest packing. The mass spectrum of 2 shows the parent peak and clear fragmentation patterns. The infrared and Raman spectra are reported for 1 and 2 in the 3000-30 cm-1 region. Most of the fundamental vibrations are assigned.
Synthese einiger phenyl-und trifluorvinylsubstituierter Phosphane / Synthesis of Some Phenyl and Trifluorovinyl Substituted Phosphanes
Authors: Horn Hans-Georg , Köntges Reinhold , Kolkmann Friedrich , Christian Heimich
Published: February 2015

Trifluorovinyl substituted phosphanes have been synthetized by reactions of halogenated phosphanes and trifluorovinyllithium. Some reactions of diphenyltrifluorovinylphosphane have been investigated and 31P as well as 19F NMR spectra have been measured. 19FNMR data - shifts and coupling constants - have been calculated for comparison with measured spectra.
3-Mercaptodihydrocarvone (True Carvone Hydrosulphide) and (1S, 4S, 5S)-4,7,7-Trimethyl-6-thia-1,5-bicyclo-[3,2,1]-octan-3-one
Authors: Hargreaves Michael , McDougall Ronald , Rabari Laljibhai
Published: February 2015

True carvone hydrosulphide has been prepared and its CD and ORD spectra examined. The spectra of another product from the reaction of carvone and hydrogen sulphide, which is probably a bi-cyclic thiane, have also been recorded.
Synthesen von Heterocyclen, CCVIII [1]. Zur Chemie der vicinalen Triketone, XI [2]. Ringverengungsreaktionen von Chinolintrionen / Syntheses of Heteroeycles, CCVIII [1]. The Chemistry of Vicinal Triketones, XI [2]. Ringcontractions of Quinolinetriones
Authors: Wittmann Helga , Günzl Friedrich
Published: February 2015

1,2,3-Trioxo-2,3,6,7-tetrahydro-1 H,5H-benzo [ij] quinolizine (I) does not react with 2-aminopyridine to give a Schiff base [2], but reacts by ringcontraction to the spiroindolone 1/I, which can be hydrolysed to 1-(2-pyridyl-amino)1,2,5,6-tetrahydro-4 Hpyrrolo[ 3,2,1-ij]quinoline-2-one (2/1). In the same way the reaction of I resp. 1-phenylquinolinetrione (II) with tert-butylamine in aliphatic alcohols yields by ringcontraction the indolone acid esters 5 a-c. Reaction of I with tert-butylamine without solvent forms the ringcontracted amide 5c/I.
Bis(tetrachloromolybdän)diazen, [MONCl4]2/Bis (tetrachloromolybdenum )diazene, [MoNCl4]2
Authors: Liebelt Wolfgang , Dehnicke Kurt
Published: February 2015

Bis(tetrachloromolybdenum)diazene, [MoNCl4]2 is prepared by the reaction of molybdenum pentachloride with iodine azide as well as by the reaction of molybdenum pentachloride with nitrogen trichloride. The IR spectrum, the mass spectrum and the magnetic moment (μeff = 1.63 B.M.) are in agreement with a N-N-bonded dimeric structure and Mo ≡ N-triple bonds.
Chalkogenolat-Ionen und ihre Derivate, V Kristall- und Molekülstruktur von 2.8-Dimethyldibenzo [c.g] [1.2.5.6] tetrathiacyclooktadien, einem Oxidationsprodukt von 4-Methylbenzol-1.2-dithiol/Chalcogenolates and their Derivatives, V Crystal and Molecular Structure of 2.8-Dimethyldibenzo[c,g][1,2,5,6]tetrathiaocin, an Oxidation Product of 4-Methylbenzene-1,2-dithiol
Authors: Kopf Jürgen , Deuten Klaus von , Nakhdjavan Bahman , Klar Günter
Published: February 2015

The structure of 2,8-dimethyldibenzo[c,g][1,2,5,6]tetrathiaocin (1b) has been determined by X-ray methods and discussed in connection with the preferred conformations of diaryl disulfides. The compound has the anti-form I. The SS-distance is 205.8 pm, the mean CSS-angle 104.1°, and the CSS/SSC-dihedral angle 111.1°.
Reaktion von Carboxamiden mit Chinolinium-Salzen bei Einwirkung von Base/Reaction of Carboxamides with Quinolinium Salts under the Influence of Base
Authors: Gündel Wolf-Hellmut , Berenbold Helmut
Published: February 2015

Carboxamides react under basic conditions with quaternary 3-cyanoquinolinium salts to give stable insertion products with 1,2-or 1,4-dihydroquinoline structure. Six examples are given.
Darstellung von Triphenylsilyl-diphenylphosphin/ Synthesis of Triphenylsilyl Diphenylphosphine
Authors: Antoniadis Antonios , Kunze Udo
Published: February 2015

The general synthetic routes to aromatic triorganylelement(IV b) diorganylphosphines are summarized and briefly discussed. By metathetical reaction of lithium or sodium diphenylphosphide and triphenylelement(IVb) chloride, triphenyltin diphenylphosphine (1) and the new compound triphenylsilyl diphenylphosphine (2) are obtained in good yields.
Chemischer Strukturbeweis für Photobilin c und ein Beitrag zu seinem Bildungsmechanismus/Chemical Structure Determination for Photobilin c and a Contribution to the Formation Mechanism
Authors: Risch Nikolaus , Belter Clemens
Published: February 2015

The structure of photobilin c is determined by oxidative degradation of 18O-labeled material which is prepared by photooxidation of a derivative of bacteriochlorophyll c in the presence of molecular 18O2.
Darstellung und Eigenschaften von Mono-, Isopoly-und Heteropolymolybdaten organischer Kationen / Preparation and Properties of Mono-, Isopoly-and Heteropolymolybdates with Organic Cations
Authors: Fuchs Joachim , Thiele Axel
Published: February 2015

In the presence of small quantities of water MoO3 is degradated by amines. In the process solvent free octa-, hepta-or monomolybdates are produced, or monomolybdates containing water of crystallization. The extent of the degradation is not dependent on the basicity of the amines but rather on the number of hydrogen-bridged bonds that the ammonium cation can form. The IR spectra indicate that the monomolybdates may be classified into 3 different structural types. In the reaction of monomolybdates with Te(OH)6, Ni(NO3)2 · 6 H2O or FeCl3 · 6 H2O in methanol hexamolybdato-tellurate, niccolate or ferrate were obtained. The solubility of iso and heteropolymolybdates in organic solvents was investigated.
Planare Komplexe von unsymmetrisch substituierten Alkyl- und Aryl-α.β-diondioximen mit den Ionen Nickel(II), Palladium(II) und Platin(II) / Planar Complexes of Unsymmetrically Substituted Alkyl and Aryl-1,2-dionedioximes with the Ions Nickel(II), Palladium(II) and Platinum(II)
Authors: Keller H. J. , Lehmann R.
Published: February 2015

A series of new planar bis(α,β-dionedioximato) metal(II) complexes of the ions Ni(II), Pd(II), Pt(II)using unsymmetrically substituted glyoximes as ligands are reported. Typical ligands being unsymmetrically substituted benzildioximes, phenylglyoxime or butan-1,2-dionedioxime.The solid state properties and in some cases the X-ray data suggest, that most of the isolated complexes crystallize in columnar stacks. Compared with the known symmetrical derivatives the solubility of the isolated neutral compounds in organic solvents like ethanol, chloroform or 1,2-dichlorobenzene is highly increased. Most of the compounds can therefore be obtained in good crystalline form. The good solubility is an advantage in the efforts to extend the polarizable ligand system of the complexes.
β,β-Diacyl-enamines and -enoles, III Formylation of CH2-acidic Compounds via the Anilinomethylene Derivatives
Authors: Wolfbeis Otto S. , Junek Hans
Published: February 2015

Three component condensation of active methylene compounds with aniline and trialkyl orthoformate gives anilinomethylene-1,3-dicarbonyls, which can be hydrolysed with aqueous K2CO3, KOH or HCl, depending on the sensitivity of the hydroxymethylene derivative thus formed. The reactions sequence is fairly generally applicable: Cyclohexan-1,3-diones, pyrimin-3,5-diones (including barbituric acids), pyrazolones and pyrazolin-3,5-diones, indan-1,3-dione, (thio)phthalide, indoxyl, oxindole, anthrone, 2,6- and 2,7-dihydroxynaphthalene, and pentan-2,4-dione have been formylated. Using orthoacetate or orthopropionate, tetronic acid, pyrazolones and pyrazolin-3,5-diones,resp.,could also be acylated by this method.
Mass Spectroscopic Fragmentation Reactions, XXI Factors Influencing the Loss of Xylene and Toluene from the Polyene Chain of Carotenoids
Authors: Johannes B. , Brzezinka H. , Budzikiewicz H.
Published: February 2015

By examining suitably substituted analogs of carotenoids the steric and electronic influences governing the elimination of xylene and toluene from the polyene chain have been clarified.
Organische Schwefelverbindungen, XXXIII CO2-Eliminierung aus Radikalkationen von Thiolestern in der Gasphase: Intramolekulare Sauerstoff-Wanderung vom (C+3/C+3)-Typ / Organic Sulfur Compounds, XXXIII CO2 Elimination from Gaseous Radical Cations of Thiol Esters: Intramolecular Oxygen Transfer of (C+3/C+3)-Type
Authors: Kohne Bernd , Praefcke Klaus , Schwarz Helmut
Published: February 2015

It is shown for the first time that under electron impact conditions an intramolecular oxygen transfer is possible from the thiol ester funtion onto the carbon atom of a second thiol ester group. The reaction sequence is terminated by CO2 elimination and the proposed structure of the resulting product ion is based on 13 carbon labelling experiments and collisional activation mass spectrometry. In addition, some unusual examples of ring contraction processes in the gas phase are reported.
The Alkyl Inductive Effect, II Theoretical Calculation of Inductive Parameters
Authors: Widingand Harry F. , Levitt Leonard S.
Published: February 2015

Three models of alkyl groups, “derealization”, “through-the-bond”, and “electric field” models, are presented, all of which enable the calculation of σI (R) from first principles, and excellent agreement is demonstrated for the calculated and experimental values of σI (R) . For the “delocalization” model it is found that - σI (R) = 0.0455 + 0.0232(1-1/n), where n is the number of C atoms in an n-alkyl group, and for an infinite C-chain R group, σI( R∞) is - 0.0687, identical to the value found b y a different method in Part I of this series. The “through-the-bond” model gives - σI(R) = - 0.0559 +

, where Ci is the number of C-atoms in the i th position from X in RX; and for the “electric field” model, we obtain - σI(R) = 0.0463 + 0.0102

, where di is the calculated distance from C1 to Cn in the most probable conformation of the R-group. It is concluded that Taft's σI(R) values have a real significance whether or not the physical and chemical effects of alkyl substitution reside ultimately in an internal induction mechanism, or in alkyl group polarization by charged centers in the molecule, or a combination of the two.
Notizen: Darstellung und Kristallstruktur des Na2AgSb / Preparation and Crystal Structure of Na2AgSb
Authors: Schuster Hans-Uwe , Mues Cornelia , Jung Walter
Published: February 2015

Na2AgSb crystallizes orthorhombically, space group Cmcm, with a = 929.2 pm, b = 790.3 pm, c = 577.3 pm. The structure contains Ag-Sb-zigzag-chains with ∢ Ag-Sb-Ag = 180° and ∢ Sb-Ag-Sb = 64.9°.
Notizen: Umwandlung gewellter Si-Schichten in einen Si-Raumnetzverband / Transformation of Corrugated Si-Layers into a Three-Dimensional Si-Network
Authors: Evers Jürgen , Oehlinger Gilbert , Weiss Armin
Published: February 2015

Corrugated Si-layers in trigonal Ca0,65Sr0,35Si2 (EuGe2 type of structure, D3d
3 -P 3̄m l, a = 389.1 pm, c = 504.8 pm, Z = 1, zSi = 0,420) are transformed by a high pressure-high temperature treatment into a tetragonal three-dimensional Si-network (a = ThSi2 type of structure, D4h
19-I 41/amd, a = 433.6 pm, c = 1367 pm, Z = 4, zSi = 0.414).
Reaktionsprodukte yon Oxylsäuremethylester-N-methylamiden mit Antimon(V)-chlorid. Molekülspektren und Struktur / Reaction Products of Oxalic Acid Methylester-N-methylamides and Antimony(V) Chloride. Molecular Spectra and Structure
Authors: Rössler M. , Schwarz W. , Schmidt A.
Published: February 2015

Oxalic acid dimethylester and the oxalic acid methylester-N-methylamides 2 and 4, resp., react with antimony(V) chloride to yield the 1 : 1 addition compound 5 or the cyclic tetrachloroantimony(V) compounds 1, 3 and 6, resp., which represent SbO2C2 and SbONC2 five ring systems, resp. Li oxalic acid methylester-N-methylimide (9) and anti-mony(V) chloride gives the bicyclic octachloro-N-methylamido oxalato-O,O′-O,N-diantimony(V) (10). The crystal and molecular structure of tetrachloro-N-methylamino oxalato-O,O′-antimony(V) (3) is determined by X-ray analysis. The vibrational and 1H NMR spectra of 2-10 are reported and discussed.
Abhängigkeit der Chlor-Isotopenseparation vom Vernetzungsgrad eines stark basischen Anionenaustauschers / Dependence of Chlorine Isotope Separation on the Degree of Cross Linkage of a Strongly Basic Anion Exchange Resin
Authors: Heumann Klaus G. , Roßmann Paul , Schwarz Anni , Windfelder Alfred
Published: February 2015

Using ion exchange chromatography, the dependence of the chlorine isotope separation on the degree of cross linkage of a strongly basic anion exchange resin was investigated. With increasing degree of cross linkage the elementary separation effect for the two stable isotopes 35Cl and 37Cl increases. In all experiments 35Cl- is enriched in the resin phase, whereas 37Cl- is enriched in the solution, using 0.1 M NaNO3 as an eluant. Within the degree of cross linkage of 2 to 10 per cent investigated, there is a linear correlation of the elementary separation effect of the chlorine isotopes with the selectivity coefficient between the ions NO3- and Cl-. The results show that the electrolyte behavior of anionic isotope exchange reactions is comparable with that of cations. The 35Cl/37Cl isotope ratio is determined using thermal ionization mass spectrometry.
Field Desorption Mass Spectra of Gastrine Peptides and Glutathione Derivatives
Authors: Przybylski Michael , Lüderwald Ingo , Kraas Ekkehard , Voelter Wolfgang , Nelson Sidney D.
Published: February 2015

Oligopeptides comprising the sequence of the C-terminal tetrapeptide of gastrine, Trp-Met-Asp-Phe-NH2, and several derivatives of glutathione, γ-Glu-Cys(SR)-Gly, were characterized by field desorption mass spectrometry. The field desorption mass spectra obtained at various field ion emitter temperatures reveal abundant molecular ions and fragmentation reactions that yield partial sequence information. In the series of glutathione derivatives investigated, characteristic ions formed by cleavage of the γ-Glu-Cys peptide bond determine the substituent at the Cys residue and can therefore be used to identify corresponding conjugation products of drug metabolites with glutathione.
Notizen: Pyrazolylphosphoran- Dimerisierung [1]. / Pyrazolyl Phosphorane Dimerisation [1].
Authors: Criegern Thomas von , Schmidpeter Alfred
Published: February 2015

The 3,5-dimethylpyrazolyl-bis(o-phenylenedioxy)- spirophospborane reversibly forms a diastereomeric dimer, gives a labile adduct with more pyrazole and with the sodium salt of pyrazole the stable bis(pyrazolyl)phosphate anion, potentially a chelating ligand.
Die Stabilisierung von Phosphanen P(NHX)3 durch Ligandenreaktionen am Pentacarbonyl(trichlorophosphan)molybdän(0) / The Stabilization of Phosphanes P(NHX)3 by Ligand Reactions of Pentacarbonyl(trichlorophosphane)molybdenum(0)
Authors: Maisch Hartmut
Published: February 2015

Phosphanes P(NHX)3, which are usually unstable, were prepared as ligands in the complexes (CO)5MoP(NHX)3 (X = H, Me, i-Pr, Ph, PhNH) (2-6) by reactions of (CO)5MoPCl3 with ammonia, primary amines, and Phenylhydrazine. Attempts to prepare (CO)5MoP(NH-t-Bu)3 were unsuccessful: however, (CO)5MoPCl3 reacts with an excess of t-BuNH2 under similar conditions to give (CO)5MoNH2-t-Bu (7) and (CO)5Mo[P(NH-t-Bu)N2-Bu]2 (8). The diazadiphosphetidin complex 8, in which the metal is bound to phosphorus, can also be prepared directly by UV-irridation of a THF solution of Mo(CO)6 and the free ligand.
Diazadistibetidine / Diazadistibetidines
Authors: Kuhn Norbert , Scherer Otto J.
Published: February 2015

Diazadistibetidines of the type (XSbNCR3)2, with X = Cl, Br and R = CH3, have been synthesized by reacting SbX3 with LiN(CR3)SiR3-The initial reaction products R3C(R3Si)NSbX2 (1) split off R3SiX with formation of the four-membered rings 2. The silylated bis(amino)-halostibines 3 do not eliminate R3SiX even at 200 °C.
Synthese und Eigenschaften von μ2 Silandiyl-Eisencarbonylen [1] / Synthesis and Properties of μ2-Silanediyl Iron Carbonyls [1]
Authors: Schmid Günter , Welz Eckhard
Published: February 2015

The synthesis of dinuclear complexes of the types [(CO)4FeSiR 1 R 2 ]2 and Fe2(CO)7(SiR 1 R 2)2 is described. IR, mass and Mössbauer spectroscopic data are discussed.
XPS Spectra of Copper and Nickel Biuret Complexes — Observations of Intense Satellite Structure in the 2P Spectrum of a Copper(III) System
Authors: Brown Dennis G. , Weser Ulrich
Published: February 2015

A series of copper and nickel biuret complexes has been studied by X-ray photoelectron spectroscopy (XPS). The results include one of the first reports of the XPS spectrum of a copper(III) complex. Significantly, this diamagnetic complex exhibits intense satellite structure in both the Cu 2P3/2 and Cu 2Pi/2 regions. The isoelectronic nickel(II) complex shows no comparable satellite structure.
Eine pentagonal pyramidale Koordination des Bismuts. Kristallstruktur von Methylbismutbis( diethyldithiocarbamat) / A Pentagonal Pyramidal Coordination of Bismut. Crystal Structure of Methylbismuthbis( diethyldithiocarbamate)
Authors: Burschka Christian , Wieber Markus
Published: February 2015

Methylbismuth-bis(diethyldithiocarbamate), X-ray The crystal structure of the title compound, recrystallized from ethanol, was solved by means of X-ray diffraction methods and could be refined to an i?-value of 0.050 with 2126 reflections observed. In contrast to its behaviour in benzene solution, where the compound is monomeric, in the crystalline state dimeric units are formed by intermolecular Bi-S-interactions. The bismuth atoms are coordinated in form of a slightly distorted pentagonal pyramid with the free electron pair presumably directed opposite the apical C-atom.
11B—NMR- spektroskopische Untersuchungen an wäßrigen Polyboratlösungen / 11B NMR Spectroscopic Studies on Aqueous Polyborate Solutions
Authors: Janda Ralf , Heller Gert
Published: February 2015

The 11B nuclear magnetic resonance spectra of sodium, potassium and ammonium polyborates in aqueous solutions, - as a function of concentration and pH - , provide information of the hydrolysis equilibria. Two 11B NMR lines are observed in aqueous solutions of Na[B5O6(OH)4], K[B5O6(OH)4] and NH4[B5O6(OH)4]. Only one 11B NMR line is recorded in aqueous solutions of (NH4)2[B4O5(OH)4] and Na2[B4O5(OH)4]. The results of the 11B NMR spectra are discussed and compared with the results obtained from Raman studies of aqueous polyborate solutions
Borverbindungen, 12. Mitteilung Das Kristallisationsverhalten der Poly(2-phenyl-1.3.2-dioxabora-cycloalkane) / Boron Compounds, Part 12 The Crystallizing Behaviour of Poly(2-phenyl-l,3,2-dioxybora-cycloalkanes)
Authors: Gerwarth Ulrich W .
Published: February 2015

The metathetic rearrangement of boron heterocycles containing an O - B (R) - O group with trivalent boron leads to oligomeric and/or polymeric ring systems. The equilibrium between the rings of different size is disturbed when crystallisation takes place. It is most probable that the monomeric rings can build up associated molecular structures with tetravalent boron atoms thus inhibiting the metathesis. But the rearrangement mechanism again rules the behaviour of the substances after melting the crystals
Nematic Liquid Crystals with High Positive Dielectric Anisotropy
Authors: Osman Maged A.
Published: February 2015

Alkylamino- and formyl alkylamino-cyano Schiff's base, biphenyl and phenylbenzoate liquid crystals were synthesized. The mesomorphic behaviour of these compounds is described. The introduction of the formyl group in the higher homologues lead to the disappearance of the mesophase. The alkylamino and formylalkylamino substituents are strong electron donating groups and lead to nematic phases with remarkably high positive dielectric anisotropy
Modifikation der N-terminalen 2-Methylthio-ethoxycarbonyl-(Mtc)-Sehutzgruppe von Peptiden mit Bromcyan / Modification of the N-Terminal 2-Methylthioethoxycarbonyl Protective Function of Peptides Using Cyanogen Bromide
Authors: Bartheis Regina , Kunz Horst
Published: February 2015

The 2-methylthio-ethoxycarbonyl (Mtc) amino protecting function of dipeptide esters (3) is converted into 2-thiocyanato-ethoxycarbonyl derivatives (6) b y treatment with cyanogen bromide. This behaviour of the Mtc-group contrasts with the cleavage of the N-acyl methionyl peptides, due to the differing nucleophilicity of the respective carbonyl oxygens