bluuebunny/crossref_metadata_2025 huggingface dataset:
YLiSn — eine ternäre Verbindung mit verzerrtem Li-Sn-Wurtzitgerüst / YLiSn - a Ternary Compound with Distorted Li - Sn - Wurtzit - Type Lattice
Authors: Steinberg Gunter , Schuster Hans-Uwe
Published: February 2015

The X-ray structure determination of YLiSn showed that Li and Sn form a weakly distorted Wurtzit-type lattice, whose octahedral lacunas are occupied by Y. The lattice constants of the hoxagonally crystallizing compound are a = 929.6 pm and c = 734.6 pm, space group P 63mc, Z = 8
Elektrochemische und elektronenspektroskopische Messungen zur Natur einfach arsenverbriickter Metall-Metall-Bindungen/Electrochemical and Electron Spectroscopic Measurements on the Nature of Singly Arsenic Bridged Metal-Metal Bonds
Authors: Honrath Ute , Vahrenkamp Heimich
Published: February 2015

For a series of singly arsenic bridged dinuclear metal carbonyl complexes with metal-metal bonds electronic spectra and dc-voltammograms in 1,2-dichloroethane were recorded. There is a reasonable correlation between the σ→σ* transitions and the first reduction potentials which can both be taken as measures of the relative strength of the metal-metal bonds. The σ→σ* excitation energy and the negative reduction potential increase (a) with increasing atomic weight of the connected metal atoms, (b) with in­creasing number of CO groups present, (c) with decreasing intramolecular steric hindrance. Steric and electronic factors cannot be cleanly separated. There seems to be no correlation with metal-metal bond lengths. Terminal phosphine ligands decrease all redox potentials but hardly change the electronic absorptions.
Ein Beitrag zum Mechanismus der triplett- sensibilisierten Photoisomerisierung des Homofulven-Systems / On the Mechanism of the Triplet Sensitized Photo-Isomerization of the Homofulvene System
Authors: Jobst Helmuth , Brune Hans Albert
Published: February 2015

Photo-reactions initiated by triplet sensitized excitation of 1,2,3,5-exo-6-pentamethyl- 4-methylene-bicyclo[3.1.0]hex-2-ene (exo-1) and 1,2,3,5-endo-6-pentamethyl-4-methylenebicyclo[3.1.0]hex-2-ene (endo-1) are studied qualitatively and quantitatively. It is demonstrated, that - in contrast to the molecular rearrangement to 1,2,3,4,6-pentamethyl- 5-methylene-cyclohexa-1,3-diene following singlet excitation - under triplet excitation exclusively reversible erro-endo-isomerization occurs.
N-Organoquecksilber-Nucleoside / N-Organomercury Nucleosides
Authors: Peringer Paul
Published: February 2015

The synthesis of the N-organomercury nucleosides C6H5HgL (LH = guanosine, inosine, thymidine, uridine) is described.
Perfluormethyl-Element-Liganden, XXI [1]. Darstellung und Charakterisierung von Organoelement-Element-Verbindungen des Typs RnE–ERm (R = CH3, CF3; E = P, As, S, Se, Te; n,m = 1, 2) / Perfluoromethyl Element Ligands, XXI [1]. Preparation and Characterization of Organoelement Element Compounds of the Type RnE–ERm (R = CH3, CF3; E = P, As, S, Se, Te; n,m = 1, 2)
Authors: Dehnert Peter , Grobe Joseph , Hildebrandt Wilhelm , Van Duc le
Published: February 2015

Element-element compounds of the general type RnE-ERm (R = CH3, CF3; E = P, As, S, Se, Te; n,m = 1, 2) have been prepared by different synthetic methods. New compounds were characterized by analytical and spectroscopic (NMR, MS) investigations. Information about the most suitable preparative route for all possible combinations is given in Tables I to III.
Cyclische Diazastannylene, VIII [1]. Die Kristall- und Molekülstruktur eines Iminostannylens: Sn3(NC(CH3 )3)4H2 / Cyclic Diazastannylenes, VIII [1]. The Crystal and Molecular Structure of an Iminostannylene: Sn3(NC(CH3 )3)4H2
Authors: Veith M.
Published: February 2015

The crystal and molecular structure of the compound Sn3(NC(CH3)3)4H2 has been determined from X-ray data (R=0.044). The crystals are cubic, space group Pa3, with cell dimension a - 1713.6(8) pm and Z = 8. The molecules, which have a seco-norcubane like Sn3N4 framework, are statistically disordered, thus forming closed packed pairs of molecules. The Sn3N4 cage deviates strongly from a cube, the bond angles at Sn approaching 80°, and at N 100°. The averaged Sn-N bond distance is 223(1) pm.
The Topochemical Reaction of CaSi2 to a Two-Dimensional Subsiliceous Acid Si6H3(OH)3 ( = Kautskys’ Siloxene)
Authors: Weiss Armin , Beil Gerd , Meyer Heinrich
Published: February 2015

Kautsky’s siloxene was prepared in a topochemical reaction from large crystals of CaSi2. The structure model was revised. Siloxene is a subsiliceous acid [Si6]H3(OH)3 and consists of two-dimensional corrugated Si-layers with three Si-Si bonds per silicon and an OH-or H-ligand, respectively. Ordering of adjacent layers is turbostratic. The layer lattice is capable of forming intercalation complexes. On intercalation only the layer distance is changed.

The alkoxylated derivatives Si6H3(OCH3)3n and Si6H3(OC2H5)3n are also able to intercalate polar molecules.
Kupfer(II)-Komplexe mit dia- und paramagnetischen Carboxylatliganden / Copper(II) Complexes with Dia- and Paramagnetic Carboxylate Ligands
Authors: Fedrigolli Richard , Schwarzhans Karl E.
Published: February 2015

The stable free radicals 4-carboxy-2,2,6,6-tetramethylpiperidinooxyl, 4-carboxy-methylene-2,2,6,6-tetramethylpiperidinooxyl, 4-carboxymethyl-2,2,6,6-tetramethylpipe-ridinooxyl and 3′-carboxy-2,2,6,6-tetramethylpiperidine-4-spiro-2′-oxirane-l-yloxyl have been prepared and used as ligands in copper(II) complexes. The magnetic moments and the EPR spectra of the complexes and the free radicals have been investigated and compared with complexes containing diamagnetic cyclohexanecarboxylic acid or cyclo -hexaneacetic acid ligands. One of the copper(II) complexes shows a considerable inter-action between the nitroxyl radicals of the ligands.
Tetrachloroaluminate, -ferrate und -gallate: AIMIIICl4 (AI = Li-Cs, NH4, Tl, In; MiIII = Al, Fe, Ga) / Tetrachloroaluminates, -ferrates and -gallates: AIMIIICl4 (AI = Li-Cs, NH4, Tl, In; MIII = Al, Fe, Ga)
Authors: Meyer Gerd , Schwan Ellen
Published: February 2015

Tetrachloroaluminates, -ferrates and -gallates of formulae AIMIIICL4 with A1 = Cs, Rb, In, Tl, NH4 as well as the high temperature forms of the potassium compounds (KMIIICl4-III) crystallize with the baryte type structure. LiMIIICL4, NaMIIICl4, and KMIIICl4-II (MIII = AI, Fe, Ga), isotypic among themselves, belong -dependent on the size of the A+ ion -to three different structure types.
Ternäre Phosphide mit ThCr2Si2 -Struktur / Ternary Phosphides with the ThCr2Si2 Structure
Authors: Mewis Albrecht
Published: February 2015

Ten new compounds with the general formula AB2P2 (A = Ca, Sr, Eu, Ba; B = Cu, Ni, Co, Fe, Mn) have been prepared and their structures determined. They are isotypic and crystallize in the ThCr2Si2 structure (space group I4/mmm) with the following constants:

CaCu1.75P2 a = 401.4 1 pm, c = 962.7(1) pm

CaNi2P2 a = 391.6 1 pm, c = 936.3(1) pm

CaCo2P2 a = 385.8 1 pm, c = 959.3(1) pm

CaFe2P2 a = 385.5 1 pm, c = 998.5(1) pm

SrCu1.75P2 a = 416.6 1 pm, c = 960.7(1) pm

EUCU1.75P2 a = 411.0 1 pm, c = 959.1(1) pm

SrCo2P2 a = 379.4 1 pm, c = 1161.0(1) pm

SrFe2P2 a = 382.5 1 pm, c = 1161.2(1) pm

BaFe2P2 a = 384.0 1 pm, c = 1244.2(1) pm

BaMn2P2 a = 403.7 1 pm, c = 1306.1(1) pm

While in Ca(Sr,Eu)Cu1.75P2 the P atoms form pairs, they are isolated from each other in the other compounds.
Die Kristallstmktiir des Iodnitren-Komplexes Cl3V ≡ N-I / Crystal Structure of the Iodonitrene Complex, Cl3V≡N-I
Authors: Liebelt Wolfgang , Weller Frank
Published: February 2015

Cl3VNI crystallizes isotypically with Cl3VNCI in the triclinic space group P1̄. The crystals contain dimeric units which are formed via chlorine bridges. The VNI group is linear with an sp-hybridized nitrogen and a V-N triple bond, (angle VNI = 163°, V-N = 165 pm, N-I = 193 pm). A short contact distance of 307 pm between the I atom and a neighbouring Cl atom is observed.
Intercalationskomplexe von Eisen(ni)oxidchlorid FeOCl mit Alkanolen / Intercalation Complexes of Iron(III) Oxide Chloride FeOCl with Alkanols
Authors: Weiss Armin , Choy Jin Ho
Published: February 2015

n-Alkanol intercalation complexes of iron(III) oxide chloride FeOCl · a n-CxHx+1OH (x = 1-18) are obtained from the amine intercalates by replacement reaction or by a "propping-open" procedure. The alkanol content is slightly variable with a = 0.54 in the alkanol richest phases and 0.46 after heating to 110 °C. In the alkanol richest phases the long chain alkanol molecules (x ≤ 12) form bilayers in the interlayer region of the FeOCl with the major part of each chain in all trans conformation and perpendicular to the layers of the host lattice. The complexes undergo a series of reversible phase transformations on heating. The arrangement of short chain alkanols (x ≤ 6) is less regular. At higher temperatures ( > 130 °C) condensation to FeO(OR)nCl1-n is observed. The alkoxylated derivatives are also capable of forming intercalation complexes.
Darstellung und Eigenschaften von Natrium-und Kaliumtetrakis(trimethylsilyl)aluminat-Komplexen / Preparation and Properties of Sodium and Potassium Tetrakis(trimethylsilyl)aluminate Complexes
Authors: Rösch Lutz , Altnau Gerald
Published: February 2015

Sodium and potassium tetrakis(trimethylsilyl)aluminate are synthesized by reaction of sodium or potassium with bis(trimethylsilyl)mercury and tris(trimethylsilyl)aluminium. Sodium and potassium tetrakis(trimethylsilyl)aluminate complexes, coordinated with diethylether, tetrahydrofurane or 1,2-dimethoxyethane are available by dissolving the unsolvated compounds in the ethers. The IR, Raman, 1H and 13C NMR spectra are discussed.
Darstellung und Eigenschaften von Molybdäntetraethoxid / Preparation and Properties of Molybdenum Tetraethoxide
Authors: Hillebrand Uwe , Stumpp Eberhard
Published: February 2015

The title compound has been isolated from reaction of MOCl5 and KOEt in ethanol. The presence of bridging alkoxy groups was proved by means of 1H NMR spectra. Magnetic susceptibility and electronic spectra were measured, and the results are discussed in terms of octahedrally coordinated Mo(IV).
Ag8SnTe6, ein neuer Vertreter der Argyrodite / Ag8SnTe6 -a New Argyrodite
Authors: Matje Peter , Schön Günter
Published: February 2015

Ag8SnTe6 has been synthesized by different methods. The Dielectric Absorption Spectra point to a silver ion conductivity.
Über Chloro- und Bromomercurate MHg5X11 (M = Tl, K, Rb, Cs, NH4; X = Cl, Br) / On Chloro- and Bromomercurates MHg5Xu (M = Tl, K, Rb, Cs, NH4; X = Cl, Br)
Authors: Brodersen Klaus , Jensen Klaus-Peter , Thiele Gerhard
Published: February 2015

The structure of TlHg5Cl11, an example of the monoclinic phases MHg5X11 (M _ TI, K, Rb, Cs, NH4; X = Cl, Br), which are found in the system alkalihalide-mercury(II)halide, was determined by X-ray structure analysis. These compounds are double salts MX · 5 HgX3, because the structure is mainly formed from X - Hg - X units.
Halogen-Elpasolithe, VI [1] Erste Iod-Elpasolithe, Cs2BIMIIII6 (BI = Li, Na) / Halo-Elpasolites, VI [1] The First Iodo-Elpasolites, Cs2BIMIIII6 ( BI = L i , Na)
Authors: Meyer Gerd
Published: February 2015

Some iodo elpasolites Cs2LiMIIII6 (MIII = Sc, Lu, Tm, Ho) and Cs2NaMIIII6 (MIII = Sc, Lu, Tm, Er) have been prepared for the first time. According to Guinier-Simon X-ray powder photographs they belong to the elpasolite type structure (cubic K2NaAlF6-type and its tetragonal distorted variety: Cs2NaMI6) or to the Cs2LiGaF6-type structure (trigonal: Cs2LiMI6). The compounds Cs2LiTmX6 (X = CI, Br, I) are further characterized by Raman spectra and magnetic susceptibilities.
Metallkomplexe mit Tetrapyrrol-Liganden, XXIV [1]. Zur Kenntnis der Platin(IV)-Porphyrine / Metal Complexes with Tetrapyrrole Ligands, XXIV [1]. On the Knowledge of Platinum(IV) Porphyrins
Authors: Buchler Johann W. , Lay Kiong-Lam , Stoppa Harald
Published: February 2015

The first platinum(IV) porphyrin, dichloromeso-tetra(p-tolyl)porphinatoplatinum(IV) [Pt(TPP)Cl2**], is prepared by oxidation of the corresponding platinum(II) complex [Pt(TTP)**] with hydrogen peroxide in acidic media and treatment with hydrogen chloride. Pt(TTP)Cl2 is thermally stable up to 200 °C. Electrochemical reduction yields Pt(TTP), presumably by a two-electron step. The platinum-to-porphyrin π-backbonding known to exist in Pt(TTP) decreases on oxidation to Pt(TTP)Cl2 but does not vanish. An improved synthesis of Pt(TTP) is described. Evidence for the accessibility of Pt(OEP)Cl2 and Pd(TTP)Cl2 is also presented.
Konformationsuntersuchungen an benzokondensierten Achtringen / Conformation Analysis of Benzo-Condensed Eight-Membered Rings
Authors: Meier Herbert , Gugel Hansjörg , Barth Margret , Plücken Udo
Published: February 2015

The annellation of 1-4 benzene rings to carbocyclic 8-rings increases stepwise the activation barrier for the ring inversion. A drastic consequence of the steric hindrance in the transition state is the rigidity of 9,10-dihydro-tribenzo[a,c,e]cyclooctenes at room temperature. With the aid of a complete analysis of the 1H NMR spectra a decision is possible between fixed C2-conformations (e.g. 8) and Cs-conformations (e.g. 9).
Zur Struktur von verbrückten Photoisomeren der Cyclodieninsektizide / Structure of Bridged Photoisomers of Cyclodiene Insecticides
Authors: Schmitzer J. , Hustert K. , Parlar H. , Körte F.
Published: February 2015

Asymmetrically substituted chlorinated tetrahydro-4,7-methano-1H-indanes can be bridged photochemically into two types of isomerization products. These photoisomers can be distinguished on the basis of different geminal coupling constants in their 1H NMR spectra. The structural assignment is not always certain, given only one photoisomer; it is unambiguous when both isomers are available.
Notizen: Neues Triterpenoid von Primula denticulata / New Triterpenoid from Primula denticulata
Authors: Ahmad Viqar Uddin , Najmus-Saqib Q. , Usmanghani K. , Fuchs W. , Voelter W.
Published: February 2015

From the alcoholic extract of the plant Primula denticulata four main compounds could be isolated by column chromatography: Pridentigenin A, B, C and D. Several spectroscopic methods and the synthesis of several derivatives allow to determine the structure of Pridentigenin B.
Verfeinerung der Struktur des Nitrids MgSiN2 - eine Neutronenbeugungsuntersuchung / A Refinement of the Structure of the Nitride MgSiN2 - a Study by Neutron Diffraction
Authors: Wintenberger M. , Tcheou F. , David J. , Lang J.
Published: February 2015

The tetrahedral wurtzite type structure of MgSiN2 has been refined with the help of neutron diffraction. The interatomic distances for Mg-N and Si-N are in complete agreement with the previously known values and the SiN4 tetrahedra in the structure are slightly deformed.
The Chemistry of Heteroarylphosphorus Compounds, Part 14 [1] Effects of Heteroaryl Substituents at Phosphorus on the Steric Course of Wittig Reactions of Semistabilised and Stabilised Ylides
Authors: Allen David W. , Ward Helen
Published: February 2015

The cis-trans ratio of the stilbenes formed in Wittig reactions of semistabilised ylides (derived from benzyltri(hetero)arylphosphonium salts in ethanolic ethoxide) with benz-aldehyde decreases markedly in the series 2-furyl >2-thienyl >phenyl > 1-methylpyrrol-2-yl. The 2-furyl group favours a greater proportion of the cis-isomer than m-trifiuoro-methylphenyl, whereas the 1-methylpyrrol-2-yl group favours a greater proportion of the trans isomer than p-methoxyphenyl. Similarly, in Wittig reactions of carbonyl-stabilised ylides with benzaldehyde and acetaldehyde, the presence at phosphorus of 2-furyl groups results in a significant increase in the proportion of the cis-alkene compared to that formed from the related triphenylphosphonium ylide.

These results are discussed in terms of both betaine and cycloaddition mechanisms for the Wittig reaction. Also discussed is their relevance to recent proposals concerning the elimination of alkene from the intermediate oxaphosphetan.
Ternäre Natriumphasen mit Cadmium bzw. Quecksilber und Zinn bzw. Blei/Ternary Sodium Phases with Cadmium or Mercury and Tin or Lead
Authors: Matthes Reinhard , Schuster Hans-Uwe
Published: February 2015

Four ternary sodium phases with the formula Na2BX (B = Cd, Hg; X = Sn, Pb) were prepared and structurally investigated. The structures of the cubic phases Na2HgSn, Na2CdPb and Na2HgPb (space group F4̄3m) are closely related to Li3Bi, that of Na2CdSn (space group P 63mmc) to the hexagonal structure of Na3As.
Notizen: Cyclophosphazenes as Novel Antitumour Agents: Geometry of the Hexaziridinocyclotriphosphazene, N3P3Az6, from an X-ray Investigation of the Benzene Clathrate
Authors: Cameron T. Stanley , Chan Christine
Published: February 2015

Hexaziridinocyclotriphosphazene forms a 2:1 clathrate with benzene. The benzene makes a sandwich between the two phosphazene molecules with the planes of the rings parallel. The geminal aziridinyl groups have a most unusual eclipsed conformation.
Darstellung und Reaktionen der Oxovanadin(V)-tricarboxylate / Synthesis and Reactions of Oxovanadium(V) Tricarboxylates
Authors: Preuss Fritz , Towae Willi , Woitschach Joachim
Published: February 2015

Monomeric oxovanadium(V) tricarboxylates VO(RCOO)3 are prepared by reaction of VOCl3 with an excess of silver carboxylate in CH2Cl2 or by depolymerization of (VO2RCOO)n in carboxylic acid anhydride. Their properties are studied by IR and 1H NMR spectroscopy as well as by chemical reactions such as thermolysis, solvolysis, redistribution and complex formation. The structure of 2,2′-dipyridyl and 1,10-phenanthroline complexes [VO(RCOO)3 · B] (B = C10H8N2, C12H8N2) has been found to be octahedral with meridional arrangement of the carboxylate ligands. Syntheses of Na[VO(CH3COO)4] and Ba[VO2(CH3COO)3] · 2CH3COOH are described
Polydentate Ligands Containing Phosphorus, III [1]. Synthesis and Nuclear Magnetic Resonance Studies of Some Unsymmetrical Potentially Tridentate Phosphine Chalcogenide Ligands
Authors: Grim Samuel O. , Satek Larry C. , Mitchell J. Dale
Published: February 2015

The synthesis via the useful lithium reagent intermediate, (C6H5)2P(S)CH2Li, is reported for eight compounds of the type [(C6H5)2P(X)][R2P(X)]2CH, where R is methyl or phenyl and X is an electron pair, oxygen, or sulfur in various combinations. Two related compounds with three and four phosphorus atoms, respectively, per molecule have also been prepared from the same lithium reagent. Tris(diphenylthiophosphoryl)methane has three equivalent phosphorus atoms as indicated by the room temperature phosphorus-31 NMR spectrum, but at reduced temperature a favored conformation exists which has two equivalent phosphorus atoms and a unique one. Other phosphorus-31 and proton NMR data are reported
Thermische Zersetzung nichtstöchiometrischer Cäsium-Silber-Gold(III)-Chloride und Darstellung von Mischkristallen zwischen Cs2AgAuCl6 und Cs2AuIAuIIICl6 / Thermal Decomposition of Nonstoichiometric Cesium-Silver-Gold(III)-Chloride and Preparation of Mixed Crystals of Cs2AgAuCl6 and Cs2Au<supI</supAuIIICl6
Authors: Berthold Hans Joachim , Ludwig Wolfgang
Published: February 2015

The thermal decomposition of cesium-silver-gold(III)-chloride Cs2Ag1-xAu1+x:/3Cl6 with 0 <x ≤ 0.63 at temperatures between 250 and 350 °C yields, under evolution of chlorine, mixed crystals of Cs2AgAuCl6 and Cs2AuIAuIIICl6. The composition of the latter can be described by the formula Cs2Ag1-y,Auy
IAuIIICl6 with y = 2x;/ (3-x). Apart from the formation of the mixed crystals the reaction leads to CsCl as a further phase, and in the case of x < 0.35 also to some Cs2AgAuCl6. Mixed crystals with 0.23 ≤ y < 1, free from additional solid phases, can be obtained from strong hydrochloric acid solutions of Cs2AgAuCl6 and Cs2AuIAuIIICl6, which contain an excess of cesium ions. The mixed crystals are isostructural with Cs2AuIAuIIICl6 (space group I4/mmm). The variation of the lattice constants with increasing silver content confirms that the univalent silver, in contrast to the univalent gold, shows no tendency toward the formation of linear dichloro complexes. Our investigations show that the "tetragonal modification of Cs2AgAuCl6", described by Elliott and Pauling and obtained by them by heat treatment of cubic cesium-silver - gold(III)-chloride, is, in fact, CS2Ag1-y/Auy
IAuIIICl6.
Synthese und Eigenschaften neuartiger eindimensionaler Leiter, 7 [1]. Poly-trans(alkinyl)phthalocyaninatosihcium(IV) / Synthesis and Properties of a New Kind of One-Dimensional Conductors. Poly-trans(alkynyl)phthalocyaninatosilicon (IV)
Authors: Mitulla Konrad , Hanack Michael
Published: February 2015

Dichloro(phthalocyaninato)silicon(IV) (1) reacts with various bis-bromomagnesium- alkynes to form the corresponding poly-trans(alkynyl)phthalocyaninat osilicon(IV) compounds (5), (11) and (18). The electrical conductivity of 5, 11 and 13 was measured with and without doping.
Über die Darstellung und Eigenschaften neuer Chloro-tris(carbonylmetaIIato)-zinn(IV)-Komplexe und die Kristallstruktur von ClSn[Fe(CO)2Cp]2[Co(CO)4]. Synthesis and Properties of New Chloro Tris(carbonylmetalato) Tin(IV) Complexes and the X-ray Structure Analysis of ClSn[Fe(CO)2Cp]2[Co(CO)4]
Authors: Moll Matthias , Behrens Helmut , Merbach Peter , Görting Klaus , Liehr Günter , Böhme Reinhild
Published: February 2015

The chloro-tris(carbonylmetalato)tin(IV) compounds, listed in Table I, are obtained by the reaction of TlCo(CO)4 or Tl[Mn(CO)5]3 with the dichloro(carbonylmetalato)tin(IV) complexes Cl2Sn[M(CO)5]2 (M = Mn, Re), Cl2Sn[Fe(CO)2Cp]2, Cl2Sn[Cr(CO)3Cp][Mn(CO)5] and Cl2Sn[Cr(CO)3Cp][Fe(CO)2Cp] in the molar ratio 1:1. Chloro-tris(carbonylmetalato)- tin(TV) compounds of the same type are also formed by treatment of TlCo(CO)4 with the trichloro(carbonylmetalato)tin(IV) complexes in the molar ratio 2 : 1. The new compounds are characterized by their analyses, mass, IR and FIR spectra. The X-ray analysis of ClSn[Fe(CO)2Cp]2[Co(CO)4] (space group P21/c) confirms the presence of 3 carbonyl - metalato groups attached to tin.
C-N-, Si-N- und P-N-Bindungsspaltung bei der Umsetzung von Phosphorpentafluorid mit einem N-Trimethylsilyl-N-tert-butylamino-substituierten Fluorphosphin und Fluorphosphoran / C-N, Si-N and P-N Bond Cleavage in Reactions of Phosphorus Pentafluoride with a Fluoro-phosphine and a Fluorophosphorane, Containing the N-Trimethylsilyl-N-tert<-butyl Group
Authors: Röschenthaler Gerd-Volker , Storzer Werner , Schmutzler Reinhard
Published: February 2015

PF5 reacts with Mo3Si(But)NPF2(E) (E = lone electron pair or OC(CF3)2C(CF3)2O) to give products whose formation can be rationalised in terms of assuming the decomposition of the intermediates F4PN(But)PF2(E) into ButF and F3P = N-PF2(E). ButF, in the presence of PF5, trimerises to give a 1 : 1 mixture of tri-iso-butene isomers. During this reaction HF is formed, giving rise to additional Si-N and P-N bond cleavage reactions in which the compounds ButNHPF2, F3P(E), ButNH3
+PF6- and NH4+PF6- are formed.
Synthese und Kristallstruktur eines Triazido-nitrido-bipyridyl-Komplexes des Molybdäns(VI): MoN(N3)3(bipy) / Synthesis and Crystal Structure of a Triazido Nitrido Bipyridyle Complex of Molybdenum(VI): MoN(N3)3(bipy)
Authors: Schweda Eberhard , Strähle Joachim
Published: February 2015

The reaction of MoCl4(bipy) with an excess of (CH3)3SiN3 in 1,2-dichloroethane results in the formation of a mixture of MoN(N3)3(bipy) and Mo(N2)Cl2(bipy). The latter is an insoluble, brownish compound of yet unknown structure. MoN(N3)3(bipy) is very soluble in 1,2-dichloroethane and easily hydrolysed. It can be crystallized from toluene in the form of explosive, red crystals of the space group P 21/n. The crystal structure is built up by monomeric complexes, in which the Mo atom has a distorted sixfold coordination. The three azido groups are located cis to the nitrido ligand, with their free electron pair at the α-N-atom pointing away from the closely neighbouring nitrido ligand. The bipyridine forms two bonds of quite different length (224,0 and 241,9 pm) with the Mo atom, as trans to the triply bounded nitrido ligand (Mo≡N = 164,2 pm) only a weak interaction is possible.
Reaktionen von 2.6.15.19-Tetrathia[7.7]paracyclophan mit Schwermetallsalzen / Reactions of 2,6,15,19-Tetrahia[7.7]paracyclophane with Heavy Metal Salts
Authors: Koray Ali R. , Ziegler Manfred L.
Published: February 2015

2,6,15,19-Tetrathia[7,7]paracyclophane reacts with salts of the soft acids Hg2+ , Ag+, Pt2+ and Pd2+ to give polymeric complexes which are insoluble in all common solvents. As expected, no products are obtained with hard acids like Li+, Na+, K+, Rb+ and Cs+.
Anwendung der 11B-NMR-Spektroskopie zur Untersuchung von Hydroborierungen, II [1]Hydroborierung von 1.5-Cyclooctadien mit Boran in Tetrahydrofuran / Application of 11B NMR Spectroscopy to the Study of Hydroboration, II [1] Hydroboration of 1,5-Cyclooctadiene with Borane in Tetrahydrofurane
Authors: Contreras Rosalinda , Wrackmeyer Bernd
Published: February 2015

The existence of various intermediates in the hydroboration of 1,5-cyclooctadiene with borane in tetrahydrofurane (BH3-THF) is revealed by 11B NMR spectroscopy. The presence of the THF adduct of 9-borabicyclo[3,3,1]nonane in solutions of the dimer in THF is proved for the first time, and the importance of the adduct in accelerating exchange reactions shown by 11B NMR spectroscopy.
Phasenbeziehungen im System Ag-As-S und thermochemisches Verhalten von Ag7MX6-Verbindungen (M = P, As, Sb; X = S, Se) / Phase Relations in the System Ag-As-S and Thermal Behaviour of Ag7MX6 Compounds
Authors: Blachnik Roger , Wickel Ulrike
Published: February 2015

The phase relations of the ternary system Ag-As-S were established by DTA and X-ray investigations. The quasibinary sections Ag2S-Ag7AsS6 and Ag7AsS6-Ag3AsS3 are described. The system Ag-As-S contains several stable compounds, including Ag7AsS6 as a member of the Argyrodit family. The compounds Ag7PS6, Ag7AsS6, Ag7PSe6, Ag7AsSe6 und AgvSbS6 were investigated by DSC and high-temperature X-ray methods. All compounds have a phase transformation from space group P213 to F4̅3m at higher temperatures. Lattice constants and transformation temperatures are given.
Kationische Thionitrosyl-Komplexe des Chroms / Cationic Thionitrosyl Complexes of Chromium
Authors: Herberhold Max , Haumaier Ludwig
Published: February 2015

A nitromethane solution of NS+PF6
-, obtained in situ from N3S3Cl3 and AgPF6 (1:3), reacts with benzene tricarbonyl chromium in acetonitrile solution to give the thionitrosyl-containing salt [Cr(NS)(NC-Me)5](PF6)2 (1)-In the presence of Zerf-butyl isocyanide and Zn powder, 1 is reduced to [Cr(NS)(CN-CMe3)5F6 (3), while subsequent oxidation of 3 with either NOPF6 or AgPF6 leads to [Cr(NS)(CN-CMe3)5](PF6)2 (5). The thionitrosyl-containing salts 1, 3 and 5 are compared with the corresponding nitrosyl complexes.
Über die Reaktion von Trifluorphosphin (PF3), Difluormethylphosphit (F2POCH3) und Trimethylphosphit [P(OCH3)3] mit Aquacobalamin in Methanol / On the Reaction of Trifluorophosphine (PF3), Difluoromethylphosphite (F2POCH3) and Trimethylphosphite [P(OCH3)3] with Aquacobalamin in Methanol
Authors: Bieganowski Rainer , Friedrich Wilhelm
Published: February 2015

Aquacobalamin reacts with trifluorophosphine in methanol. The products, fluoromethylphosphito- P-cobalamin and dimethylphosphito-P-cobalamin, were identified and characterized by means of electrophoresis, NMR (1H, 31P, 19F) and X-ray structure analysis. Both cobalamins were synthesized in a similar way using difluoromethylphosphite and trimethylphosphite as reagents. Fluoromethylphosphito-P-cobalamin is much less soluble in water than cyanocobalamin. Dimethylphosphito-P-cobalamin is lightsensitive. Both cobalamins crystallize from water and methanol/water.
Solubilization and Photoreaction of Thiazine Dyes in Reversed Micelles
Authors: Miyoshi Norio , Tomita Giiti
Published: February 2015

Thiazine dyes were solubilized very slowly in dodecylammonium propionate reversed micellar cyclohexanic solutions containing 0.5 M H2O. Light accelerated highly the solubilization of the dyes. The dye monomer band blue-or red-shifted by the solubilization dependent on the dye species. Thiazine dyes solubilized in the reversed micelles containing 0.1 M H2O exhibited a new absorption band at about 500 nm.

The photoreduction of thiazine dyes by allylthiourea was enhanced drastically by solubilizing the dyes in the reversed micellar solutions containing 0.5 M H2O, and the singlet oxygen production was also effectively photosensitized by the solubilized thiazine dyes. The relative quantum yields for the photoreduction of the dyes by allylthiourea and the furan oxidation by singlet oxygen produced by the photosensitization of the dyes were obtained in the reversed micellar solutions. Results obtained were discussed in connection with the solubilization.
Untersuchungen an natürlichen γ und δ-Laktonen, X [1] Synthese von Umuravumbolid und Epiumuravumbolid / Investigations on Naturally Occuring γ-and δ-Lactones, X [1] Synthesis of Umuravumbolide and Epiumuravumbolide
Authors: Achenbach Hans , Witzke Joachim
Published: February 2015

6-(3-Acetyloxy-1-heptenyl)-5,6-dihydro-2H-pyran-2-one (= umuravumbolide), the new α-pyrone recently isolated from leaves of the central African Iboza riparia, and its diastereomer, epiumuravumbolide, were synthesised.
Struktur-Wirkungsbeziehungen polyfunktioneller Diterpene des Tigliantyps, IV [1-3]. Derivate des Tiglians mit fehlendem oder geöffnetem Cyclopropanring und ihre irritierende und tumorpromovierende Wirkung / Structure-Activity Relationships of Polyfunctional Diterpenes of the Tigliane Type, IV [1-3]. Derivatives of Tigliane without or with Opened Cyclopropane Ring and their Irritant and Promoting Activity
Authors: Sorg Bernd , Gschwendt Michael , Thielmann Heinz Walter , Hecker Erich
Published: February 2015

The synthesis of the esters 6d-8d, 9 c and 10 c is described. These compounds are closely structurally related to the irritant and tumorpromoting 12-O-tetradecanoylphorbol-13-acetate (TPA, 2 a) and to phorbol-12,13-didecanoate (PDD, 2 c) except that they possess no cyclopropane ring. Biological tests show that opening or complete removal of the cyclopropane ring leads to nearly total loss of irritant or tumorpromoting (tested in the case of 9 c and 10 c) activity.
Reaktionen am Cyclotrisilazan-System - Synthese und Molekülstruktur eines 1.3.5.7-Tetraaza-2.4.6.8-tetrasila-bicyclo [4.2.0] octans / Reactions of the Cyclotrisilazane System - Synthesis and Molecular Structure of a 1,3,5,7-Tetraaza-2,4,6,8-tetrasilabicyclo[4,2,0]octane
Authors: Clegg William , Klingebiel Uwe , Sheldrick George M. , Skoda Lutz , Vater Norbert
Published: February 2015

1,3-Dilithio-5-trimethylsilyl-2,2,4,4,6,6-hexamethylcyclotrisilazane (1) reacts in a 1:2 molar ratio with difluorodimethyl- or trifluoromethylsilane to give substitution at the lithiated N atoms. The reaction of the bis(fluorodimethylsilyl)-substituted compound with more of 1 produces ring contraction, to form a silyl-bridged tris(cyclodisilazane). In the reaction of the bis(difluoromethylsilyl)-substituted cyclotrisilazane with more of 1, however, the title compound, a fused ring system, is formed. This compound has been characterised by crystal structure determination. The mechanism of its formation is discussed.
Acyl-und Alkylidenphosphane, XV 2.2-Dimethylpropylidinphosphan, eine stabile Verbindung mit einem Phosphoratom der Koordinationszahl 1/ Acyl- and Alkylidenephosphines, XV 2,2-Dimethylpropvlidynephosphine, a Stable Compound with a Phosphorus Atom of Coordination Number 1
Authors: Becker Gerd , Gresser Gudrun , Uhl Werner
Published: February 2015

In the presence of small amounts of solid sodium hydroxide, [2,2-dimethyl-l-(trimethylsiloxy)propylidene]-trimethylsilylphosphine reacts at + 20 °C to give hexamethyldisiloxane and 2,2-dimethylpropylidynephosphine (2). In contrast to similar alkylidynephosphines this compound is stable at room temperature. The IR and mass spectrum are discussed, and 1H, 13C and 31P NMR spectral data are given.
Solutions of Lithium Tetrahydrido Aluminates in Ethers: a 7Li and 27Al NMR Study
Authors: Nöth Heinrich , Rurländer Robert , Wolfgardt Peter
Published: February 2015

Solutions of LiAlH4 in tetrahydrofuran (THF), glycoldimethylether (monoglyme), diglycoldimethylether (diglyme) and triglycoldimethylether (triglyme) as well as solutions of LiAlH4/THF in toluene have been investigated by 7Li and 27Al NMR. It was found that δ27Al is nearly independent of the solvent as is 1J(AlH). However, the line width of the 27A1 NMR signal shows strong solvent influences and, in addition, concentration and temperature dependence. Intermolecular hydride exchange becomes rapid in solutions of monoglyme and triglyme at room temperature. This can also be shown by the H/D exchange between LiAlH4 and LiAlD4. δ7Li data indicate that Li is hexacoordinated in the series of glycoldimethylethers, and LiAlH4 in diglyme seems to be the system in which the AlH4 moiety is least affected by ion pair or triple ion formation.
Perfluormethyl-Element-Liganden, XXIV Organozinnverbindungen als Reagenzien, III Spaltungsreaktionen der Element-Element-Bindung in Verbindungen des Typs RnE-ERm(R = CH3, CF3·E =P, As, Se, Te · n,m = 1, 2)/Perfluormethyl Element Ligands, XXIV ; Organotin Compounds as Reagents, III Cleavage Reactions of the Element-Element-Bond in Compounds of the Type RnE-ERm (R = CH3CF3; E = P, AS, S, Se, Te; n,m=1, 2)
Authors: Dehnert Peter , Grobe Joseph , Le Van Duc
Published: February 2015

A systematic study of the cleavage of element-element bonds in compounds of the type RnE-ERm (R = CH3, CF3; E = P, As, S, Se, Te; n,m = 1, 2) by the group IV A element hydrides Me3M′H (M′ = Si, Ge, Sn; Me - CH3) has been carried out. To evaluate the reaction pathway, for a number of compounds the attack of H2O, CH3OH, HBr and HI has been investigated. Possible reaction intermediates have been synthesized by independent routes and tested under comparable conditions.
Notizen: Eine nicht erwartete intramolekulare Photoreaktion eines Hexachloroctahydrodimethanonaphthalins/An Unexpected Intramolecular Photoreaction of a Hexachlorooctahydrodimethanonaphthaline
Authors: Parlar H. , Inanici Y.
Published: February 2015

Photoreactions of 1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo, endo-5,8-dimethano-naphthaline (1) were studied in acetone with wavelengths above 290 nm. With the help of column chromatography an unusual isomerisation product (4) could be isolated, whose structure was established by spectral data obtained by mass spectrometry infrared spectroscopy, 1H and 13C nuclear magnetic resonance measurements.
Darstellung von Natrium-Chelaten des Methylen-bis[iminodiphenylphosphorans] [1] / Synthesis of Sodium-Chelates of Methylen-bis[iminodiphenylphosphorane] [1]
Authors: Appel Rolf , Waid Karl
Published: February 2015

The methanido-bis(aminophosphonium) salts

3a-d can easily be synthesized by CCl4-reaction of Ph2PCH2PPh2. Their structure is confirmed by 31P{1H} and 13C{1H} NMR data. Dehydrohalogenation by NaH yields the methanidobis( phosphoranylamide/imide) 4 c. Several possible tautomers of 4c are discussed. With excess NaH the salts 3 a-d react to form the sodium-[methanido-bis(diphenylphosphoniumimides)] 5 a-d, sodium chelates of 4.
Zur Reaktion aromatischer Phosphanderivate mit Elektronen, I. / On the Reaction of Aromatic Phosphane Derivatives with Electrons, I.
Authors: Kaim Wolfgang
Published: February 2015

The compounds ;p-Me2P(X)-C6H4-P(X)Me2, X = O, S, Se, NPh undergo one-electron reduction at a mercury cathode or on reaction with solvated electrons in a K/18-crown-6/THF mixture. The radical anions formed are persistent and have been characterized by ESR. They may be described as complexes of the spin-bearing moiety p-Me2P-C6H4-PMe2 · with the coordinated groups X.
(Aminoethinyl)metallierimgen, IX [1] Umsetzungen von Inaminen mit Cyanketenen / (Aminoethynyl)metallations, IX [1] Reactions of Ynamines with Cyanoketenes
Authors: Himbert Gerhard , Fachbereich Lothar Henn
Published: February 2015

Ynamines 2 bearing methyl or phenyl groups at their C/C triple bond react with tert-butylcyanoketene 1a to give the cyclobutenones 3 and/or the allene carboxamides 4. 3 and 4 are the products of two different [2 + 2] cycloaddition reactions.

β-Silylated, β-germylated and β-stannylated ynamines 5 add the cyanoketenes 1 under "(aminoethynyl)metallation" to furnish the new enynamines 6. These compounds were characterized by IR and 1H NMR spectroscopy and partly by mass spectrometry.

The stannyl derivatives of 6 hydrolyze very easily to the corresponding acyl ynamines 7 and react with 4-nitrobenzoyl chloride to give the 1-(aminoethynyl)vinyl benzoates 8. The diazo compound 9 is formed by the interaction of tosyl azide on the enynamine 6 c, which is probably first hydrolyzed to 7a. N,N-Diethyl-N-(triphenylsilylethynyl)amine (5e) reacts with two molecules of tert-butylcyanoketene (1a) to give the allene derivative 10, probably via the corresponding enynamine 6 (R1 = R2 = Et, MR3
3 = SiPh3, R4 -tBu).
Redox Properties of Platinum Uracil "Blues": A New Type of Paramagnetic Species
Authors: Seul M. , Neubacher H. , Lohmann W.
Published: February 2015

The observation of a new type of ESR spectrum in the course of redox experiments on a platinum uracil "blue" compound is reported. Some characteristic features of the ESR and optical absorption spectra are described. A tentative analysis of the ESR spectrum is pre-sented, based on the assumption of localized states.
Interhalogen-Kationen: Darstellung und Kristallstrukturen (143 K) von I3Cl2SbCl6, I3Cl2AlCl4 und I3Br2SbCl6 / Interhalogen Cations: Preparation and Crystal Structures (143 K) of I3Cl2SbCl6, I3Cl2AlCl4 and I3Br2SbCl6
Authors: Pohl Siegfried , Saak Wolfgang
Published: February 2015

The title compounds were prepared and their crystal structures determined from low temperature single crystal X-ray data. The structures contain the anions SbCl6
- and AlCL4
-and the novel interhalogen cations I3Cl2
+ and I3Br2
+ . Anions and cations are linked to infinite chains by weak covalent bonds.
Zum Thermolyseverhalten von 2.2-Dihydro-1.4.2-oxazaphosphol-4-enen, I. Über die Dimerisierung von bis(trifluormethyl)substituierten Nitril-yliden [1, 2] / Thermolysis of 2,2-Dihydro-1,4,2-oxazaphosphol-4-enes, I. Dimerization of Bis(trifluoromethyl) Substituted Nitrile Ylides [1, 2]
Authors: Burger Klaus , Goth Herbert , Einhellig Kurt , Gieren Alfred
Published: February 2015

3,3-Bis(trifluoromethyl)-2,2,2-trimethoxy-2,2-dihydro-1,4,2-oxazaphosphol-4-enes (1) on thermolysis undergo a 5→[3 + 2]cycloreversion reaction with formation of trifluoro- methyl substituted nitrile ylides (2). The latter dimerize to produce 3,6-diazaocta-2,4,6- trienes (3a, 6) which may react further to yield 6,12-dihydro-dibenzo[c,h][1,5]naph- thyridines (10), and syn/anti 4-ethylimino-1,4-dihydroisoquinolines (12/13). The naphthyridines (10) on treatment with cone. KOH are transformed into 3,3'-bis(1H-isoindoles) 11. Lithium aluminium hydride reduction of the 4-ethylimino-1,4-dihydroisoquinolines (12/13) yields 4-ethylimino-1,2,3,4-tetrahydroisoquinolines (14). A reaction mechanism for the 1,3-dipole dimerization of bis(trifluoromethyl)substituted nitrile ylides is discussed.
Kinetische Untersuchungen zur Wasserstoffübertragung von Dihydropyridinen auf Hydrazyle / Kinetic Investigation on the Hydrogen Transfer from Dihydropyridines to Hydrazyls
Authors: Abou-Elenien G. , Rieser J. , Ismail N. , Wallenfels K.
Published: February 2015

The results of a kinetic study on the hydrogen transfer between different dihydropyridines and mono-, bis-and trishydrazyls of the tricyanobenzene series are described. The reactions have been found to obey in all cases a second-order law. The influences of solvent medium, redox-potentials of the reactants and temperature on the rates of reactions have been investigated.
Energiebilanz einer Reaktion zwischen Radikal-Kation und Radikal-Anion / Energy Turnover of a Reaction between Radical Cation and Radical Anion
Authors: Stanienda Alfred
Published: February 2015

⊿G for the reaction R·+ + R·- → 2 R + ⊿G was calculated according to ⊿G = -(IP-EA) = -⊿ E1 for the reaction in gas phase under ideal conditions. The result was compared with ⊿H in solution measured calorimetrically and the entropy term measured voltammetrically according to ⊿G = ⊿H - T⊿S. Both values for ⊿G agreed satisfactorily. From this it was derived that the solvation energies of R·+ and R·- compensate mutually. The Coulomb energies have little influence on ⊿G only
Temperature Dependent ESR Studies on Platinum Pyrimidine “Blues”: Evidence for a Structural Instability ?
Authors: Seul M. , Neubacher H. , Lohmann W.
Published: February 2015

Frozen samples of aqueous solutions of oxidized Pt 6-methyl-uracil “blue” were studied by ESR spectroscopy at temperatures T ranging between - 196 °C and - 10 °C. When T was raised a distinct change in the line pattern was observed at about -35 °C. The resulting type of spectrum is very similar to the ESR spectrum of MAGNUS’ Green Salt. The observed effect is suggested to be due to a change of the nature of the system’s electronic states possibly indicating a structural rearrangement
Tl2Sn2S5, ein Thallium(I)thiostannat(IV) mit fünffach koordiniertem Zinn / Tl2Sn2S5, a Thallium(I) Thiostannate(IV) with Fivefold Coordinated Tin
Authors: Eulenberger Günther
Published: February 2015

The new compound Tl2Sn2S5 was prepared by fusion of a stoichiometric mixture of the elements followed by prolonged heating at 300 °C. The compound crystallizes in the monoclinic system in space group C2/c with lattice constants a - 11.115(2), 6 = 7.723(1), c = 11.492(2) Å, and β = 108.60(1)° (Z = 4). The Sn atoms are coordinated by five S atoms forming a considerably distorted trigonal bipyramid (mean distance Sn-S: 2.497 Å). By common edges the SnS5 bipyramids are linked into chains extending in the [110] and [11̄̄0] directions, respectively. The chains are cross-linked by sharing the remaining equatorial vertices of the SnSs bipyramids, thus forming a three-dimensional framework which is related to that described for Na4Sn3S8 [1]. The Tl atoms located in channels running parallel to the b axis are surrounded by nine S atoms. The distances Tl-S vary from 3.073 to 3.897 Å.
Untersuchungen über den Verlauf der Hydrolyse einiger Borsäurealkylester und den Nachweis von Zwischenprodukten / Investigations on the Course of the Hydrolysis of Some Tris(alkoxy)boranes and the Identification of Intermediates
Authors: Steinfeldt Karl-Peter , Heller Gert , Baumert Reinhard
Published: February 2015

In the course of the hydrolysis of tris(alkoxy)boranes B(OR)3 (R = methyl, n-butyl, or 2-ethylhexyl) with a small amount of water in organic solvents, both possible intermediates (RO)2BOH and ROB(OH)2 have been unambiguously identified by Raman spectroscopic measurements. Lines have been found for (CH3O)2BOH at 772.8 cm -1 and for CH3OB(OH)2 at 814.6 cm -1 . The compounds are in equilibrium with the starting material B(OCH3)3 and the product B(OH)3.

Potentiometrie and conductometric investigations likewise indicate the existence of these species. A mechanism of the hydrolysis reaction is based on kinetic considerations.

With hydroxide ions in non-aqueous solvents or aqueous hydroxide ions the hydrolysis reactions occur differently because in the first case the end product of the hydrolysis is the orthoborate ion [B(OH)4]-, whereas in the second case in concentrated aqueous solutions poly borates are formed.
10B-, 11B-, 13C-NMR-Untersuchungen von closo-Pentaalkyl-1.5-dicarbapentaboranen(5) / 10B-, 11B-, 13C NMR Studies of closo-Pentaalkyl-1,5-dicarbapentaboranes(5)
Authors: Köster Roland , Wrackmeyer Bernd
Published: February 2015

NMR parameters [chemical] shifts (δ11B, δ13C) and coupling constants (1J(13C1H), 1J(13C11B), 1J(13C13C), 1J(11B11B) of closo-pentaalkyl-1,5-dicarbapentaboranes(5) were determinated by 10B, 11B, and 13C NMR spectroscopy. The magnitudes of 1J(13C11B) and 1J(13C13C) correspond to 1J(11B1H), 1J(13C11B) and 1J(13C1H) in the parent compound 1,5-C2B3H5 . According to predictions from MO calculations 1J(11B11B) was found to be < 10 Hz. Together with these data the δ11B and δ13C values show that neither the structure nor the bonding situation in the polyhedron are significantly affected by alkyl substitution.
Phosphate Production and Analysis in the Non-Enzymatic Activation of Amino Acids by ATP when Using Hydroxylamine as a Trapping Agent
Authors: Mullins Dail W. , Lacey James C.
Published: February 2015

Phosphate Production, Hydroxylamine, ATP Saygin and Decker [6, 7] have reported that the formation of hydroxamic acids in solutions containing ATP, MgCl2, hydroxylamine and an acidic acceptor (acetic acid or amino acids) is not accompanied by the release of inorganic phosphate from ATP. Using an ion exchange chromatography method developed by Lowenstein [8] to separate the various components of such reaction mixtures, we now show that inorganic phosphate, as well as some pyrophosphate, is produced during incubation at 50 °C. Evidence is also presented to indicate that the failure of Saygin and Decker [6, 7] to detect phosphate is due to a total inhibition of their phosphate assay system by ATP.
Solvent Induced Circular Dichroism in Conformational Analysis: Bile Pigments
Authors: Lehner Harald , Krauss Corinna , Scheer Hugo
Published: February 2015

The applicability of solvent induced circular dichroism (SICD) for the conformational analysis of bile pigments has been investigated. The S-(-)-ethyl lactate induced rotational strengths for octaethylbilindion (4) and its dihydroderivative 5 are remarkably high. Related compounds, e.g. the isomeric purpurines 1 and 2 and formyltripyrrinon 3 exhibit an optical activity which is smaller by more than one order of magnitude. 1-3 are essentially free from steric strain so that a flat arrangement of the chromophore is most likely. On the other hand the closed conformations of 4 and 5 experience considerable steric repulsion of their terminal rings, so that a helical topology is energetically favoured. This distinction is reflected in the magnitude of the SICD observed and demonstrates its applicability for the conformational analysis of bile pigments.
Elektrochemisches Verhalten der Nitrophenole und ihrer Reduktionsprodukte an Graphitelektroden/ Electrochemical Behavior of the Nitrophenols and Their Reduction Products at Graphite Electrodes
Authors: Theodoridou Elli , Jannakoudakis Dimitrios
Published: February 2015

The electrochemical reduction of the isomeric nitrophenols at graphite electrodes is investigated in aqueous solutions with pH = 1-13 and is compared with the electro-chemical oxidation of their reduction products. o-Nitrophenol and p-nitrophenol are reduced to the corresponding amines, as the observed oxidation peaks in their cyclic voltammograms can be simulated by those of o-and p-aminophenol. m-Nitrophenol is reduced to m-hydroxylaminophenol, as its oxidation peak appears at much more negative » potential than that of m-aminophenol, within the potential range of the oxidation of phenylhydroxylamine.

The pH-dependence of the reduction potentials of the nitrophenols at the graphite electrodes is discussed in comparison with that at a hanging mercury drop electrode.
Azulen-Naphthalin-Umlagerung. Thermolyse von [4.7-13C2] -Azulen/ Azulene-Naphthalene Rearrangement. Thermolysis of [4,7-13C2] Azulene
Authors: Zeller Klaus-Peter , Wentrup Curt
Published: February 2015

The mixture of 13C2-labelled naphthalenes obtained by flash vacuum thermolysis of [4,7-13C2] azulene (9) consists of [1,4-13C2]- (14) and [2,10-13C2] naphthalene (10) as major products and [1,3-13C2]naphthalene (11) as a minor product. Traces of [1,6-13C2]- (12) and [1,7-13C2] naphthalene (13) are also detectable. The recently proposed vinylidenenorcaradiene mechanism [5] correctly predicts the major products.