bluuebunny/crossref_metadata_2025 huggingface dataset:
Notizen: Chiralität durch gehinderte Rotation: Isolierung optisch aktiver Naphthylamine / Chirality Caused by Hindered Rotation: Isolation of Optically Active Naphthylamines
Authors: Herbst Thomas , Schiemenz Günter P.
Published: March 2015

Racemic 1-[(ethyl)(methyl)amino]-8-[(hydroxy)-di(phenyl)methyl]-naphthalene was resolved by column chromatography. The enantiomers are stable at room temperature.
Notizen: Chirale Ruthenium-Halbsandwichkomplexe des Schwefelmonoxids und Schwefeldioxids [1] / Chiral Ruthenium Halfsandwich Complexes of Sulfur Monoxide and Sulfur Dioxide [1]
Authors: Schenk Wolfdieter A. , Karl Ute
Published: March 2015

Chiral halfsandwich complexes of sulfur monoxide and sulfur dioxide, [C5Me5RuCl(PR3)(SOx)] (R = isopropyl, cyclohexyl, x = 1, 2), were prepared from the coordinatively unsaturated precursors [C5Me5RuCl(PR3)]. The new compounds were characterized by 1H 13C, 31P and IR spectroscopy.
Übergangsmetallkomplexe mit Schwefelliganden, XLVIa. Zn-, Cd-, Hg-, Sn-, Pb-, Sb-, Bi- und Ti-Komplexe mit den zwei- und vierzähnigen Thiolatliganden 'buS2
'2- = 3,5-Di(t-butyl)benzol-1,2-dithiolat(2—), 'S4
'2- = 1,2-Bis(2-mercaptophenylthio)ethan(2—) und 'buS4
'2- = 1,2-Bis(3,5-di(t-butyl)-2-mercaptophenylthio)ethan(2–) / Transition Metal Complexes with Sulfur Ligands, XLVIa. Zn, Cd, Hg, Sn, Pb, Bi and Ti Complexes with the Bi- and Tetradentate Thiolato Ligands 'buS2
'2- = 3,5-Di(t-butyl)benzene-1,2-dithiolate(2–), 'S4'2 = 1,2-Bis(2-mercaptophenylthio)ethane(2–) and 'buS4'2- = 1,2-Bis(3,5-di(t-butyl)-2-mercaptophenylthio)ethane(2 – )
Authors: Sellmann Dieter , Freyberger Gerhard , Moll Matthias
Published: March 2015

Syntheses of neutral 'buS2'-, 'S4'- and 'buS4'- and of anionic .buS2-complexes with various main group and transition metals are described. The complexes were prepared by reacting the neutral sulfur ligands or their alkali salts with the metal halide or alkoxide. The ligands coordinate to metal ions in normal as well as high oxidation states. No redox reactions occur in the latter case. The complexes are usually soluble in organic solvents and were characterized by elemental analysis and spectroscopic means.
Stereoselective Synthesis of a Phenylphosphido-Bridged Dimetallic Complex: Crystal and Molecular Structure of [(R̲*,R̲*),(R̲*)]-(±)-[η5-C5H5){1,2-C6H4(PMePh)2}FePHPh{Cr(CO)5}] · 2 H2O · 0.5 CH2Cl2 · 0.5 C4H8O
Authors: Hey Evamarie , Willis Anthony C. , Wild S. Bruce
Published: March 2015

Deprotonation of (R̲*,R̲*)-(±))-[η5-C5H5){1,2-C6H4(PMePh)2}Fe(PH2Ph)]PF6 with n-BuLi in tetrahydrofuran at 20°C, followed by treatment of the intermediate phenylphosphido-iron complex with [Cr(CO)5(NMe3)] produces a separable 3: 2 mixture of the diastereomers [(R̲*,R̲*),(R̲*)]- and [(R̲*,R̲*),(S̲*)]-(±)-[(η5-C5H5){1,2-C6H4(PMePh)2}Fe-PH(Ph) → Cr(CO)5]. The major component of the mixture crystallizes from dichloromethane-tetrahydrofuran in the atmosphere as the mixed solvate (R̲*,R̲*)-(±))-[η5-C5H5){1,2-C6H4(PMePh)2}Fe(PH2Ph)]Fe-PH(Ph) → Cr(CO)5]· 2 H2O-0.5 CH2Cl2 · 0.5 C4H8O in the triclinic space group P1̅ with two formula units in the unit cell; the lattice constants are a = 10.933(2) Å, b = 13.161(4) Å, c = 15.249(3) Å, α = 76.83(1)°, β = 75.62(3)°, and γ = 79.31(1)°. In the structure, the pyramidal phenylphosphido group bridges the dissimilar metals via relatively long metal-phosphorus bonds, viz., Fe-P = 2.285(5) Å, Cr-P = 2.511(4) Å.
Aliphatic Bis(acyl) Selenides — Synthesis and Characterization
Authors: Kageyama Hideki , Tsutsumi Hideharu , Murai Toshiaki , Kato Shinzi
Published: March 2015

A series of aliphatic bis(acyl) selenides 1 were isolated from the reaction of acyl chlorides with sodium selenide and characterized.
Bioanorganische Modellkomplexe für Metalloproteine des Eisen(III): Synthese, Kristallstrukturen und Magnetismus der zweikernigen Komplexe [L2Fe2
III(µ-O)(μ-SO4)2] · 3 H2O und [L2Fe2
III(μ-O)(μ-SO3)2] · 5/3 NaClO4 · (H2O)3.67 (L = N,N′N″-Trimethyl-1,4,7-triazacyclononan) / Bioinorganic Model Complexes for Metalloproteins of Iron(III): Syntheses, Crystal Structures, and Magnetism of the Binuclear Complexes [L2Fe2
III(μ-O)(μ-SO4)2]·3 Η2O and [L2Fe2
III(μ-O)(μ-SO3)2] · 5/3 NaClO4 · (H2O)3.67 (L = N,N′,N″-Trimethyl-1,4,7-triazacyclononane)
Authors: Wieghardt Karl , Drüeke Stefan , Chaudhuri Phalguni , Flörke Ulrich , Haupt Hans-Jürgen , Nuber Bernhard , Weiss Johannes
Published: March 2015

The reaction of LFeCl3 (L = N,N′,N″-trimethyl-1,4,7-triazacyclononane) with Na2SO4, Na2SO3/NaClO4, and Na2SeO3/NaClO4 in aqueous solution affords the binuclear oxo bridged complexes [L2Fe2(μ-Ο)(μ-SΟ4)2]·3Η2Ο (1), [L2Fe2(μ-O)(μ-SO3)2]·5/3NaClO4·(H2O)3.67 (2), [L2Fe2(μ-O)(μ-SeO3)2](NaClO4)2.75·5H2O (3). The reaction of LFeCl3 in dry methanol with Na2SO4 yields yellow crystals of [L2Fe2(μ-SO4)3] · 2 H2O (4). The crystal structures of 1 and 2 have been determined by X-ray crystallography. Crystals of 1, 2, and 3 consist of neutral, binuclear μ-oxo bridged diiron(III) complexes which contain two additional O,O′-coordinated sulfato, sulfito, and selenito bridging ligands, respectively. The high spin ferric ions in 1, 2, and 3 are strongly intramolecularly antiferromagnetically spin exchange coupled with J values of —97(1), -104(2), and —104(2) cm-1 (H = —2JŜ,·Ŝ2, S1 = S2 = 5/2), respectively. 4 contains three μ-sulfato bridges between two FeIII ions. Only a very weak antiferromagnetic coupling has been detected (J = —5.5(5) cm-1). Complex 1 serves as a model compound for the diiron(III) complex of the sulfate treated, oxidized form of the biomolecule uteroferrin.
One Pot Synthesis of Methyl 3-Methyl-4H-1,4-benzothiazine 2-carboxylates
Authors: Gupta R. R. , Jain S. K. , Gupta Vandana , Rathore R. K.
Published: March 2015

Methyl 3-Methyl-4H-1,4-benzothiazines 2-Carboxylate

A one pot synthesis of methyl 3-methyl-4H-1,4-benzothiazine 2-carboxylates is reported by the condensation and oxidative cyclization of substituted 2-aminobenzenethiols with methyl acetoacetate in DMSO.
f-Element-Komplexe mit Schwefel-Stickstoff-Chelatliganden: Synthese und Struktur von [PhS(NSiMe3)2]2UCl2 / f-Element Complexes with Chelating Sulfur-Nitrogen-Ligands: Synthesis and Structure of [PhS(NSiMe3)2]2UCl2
Authors: Knösel Friedrich , Noltemeyer Mathias , T. Edelmann Frank
Published: March 2015

Li[PhS(NSiMe3)2]-0.5 Et2O (1) is prepared by treatment of Me3SiNSNSiMe3 with phenyllithium. The lithium salt 1 reacts with UCl4, ScCl3(THF)3 and NdCl3(THF)2 to give di-, and trisubstituted complexes containing the chelating [PhS(NSiMe3)2] ligand. [PhS(NSiMe3)2]2UCl (2) has been characterized by an X-ray structure determination.
Cu2+-, Pd2+- und Pt2+-Komplexe mit [(en)2Co(OH)2]+-Liganden / Cu2+-, Pd2+- and Pt2+-Complexes with [(en)2Co(OH)2]+ Ligands
Authors: Thewalt Ulf , Müller Susanne
Published: March 2015

[(en)2Co(H2O)2](ClO4)3 reacts with CuSO4·5H2O, K,[PdCl4], or K,[PtCl4] to form the heterometallic complexes [Cu{(OH)2Co(en)2}2](ClO4)4·2H2O (1), [Pd{(OH)2Co(en)2}2](ClO4)4·2H,O (2), [PdCl2{(OH)2Co(en)2}]2[PdCl4] (3) or [PtCl2{(OH)2Co(en)2}]2[PtCl4] (4), respectively, containing [(en)2CoIII(OH)2]+ ligands. The central metal(2+) cations in these complexes have a square planar coordination geometry. This has been confirmed by X-ray structure analyses.
Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XXXV [1]: Synthese und dynamisches Verhalten von Dicarbonyl[η5:1-(2-cyclopentadiendiyl)ethyl](η2-olefin)molybdän und -wolfram / Hindered Ligand Motions in Transition Metal Complexes, XXXV [1]: Synthesis and Dynamic Behaviour of Dicarbonyl[η5:1-(2-cyclopentadiendiyl)ethyl](η2-olefin)molybdenum and -tungsten
Authors: Kreiter Cornelius G. , Wenz Martin , Michels Wolfgang
Published: March 2015

In order to investigate the coordination ability of quasi square pyramidal complexes, tricarbonyl[η5:1-(2-cyclopentadiendiyl)ethyl]molybdenum (1) and -tungsten (2) were reacted photochemically with ethylene (a), propene (b), 1-butene (c), Z-2-butene (d), E-2-butene (e), 2-methyl-propene (f), 2-methyl-2-butene (g), 2,3-dimethyl-2-butene (h), styrene (i), 2,2-dimethylcyclopropene (j), allene (k) and acetylene (I). 1 forms [Μο(η5:1-C5Η4C2H4)(CO)2(η2-olefin)] complexes with a—g, i, and k, 2 the corresponding tungsten complexes with a, g, h, and j as ligands. There is no reaction between 1 or 2 and acetylene. 1g and 2h represent the limits for complexes with sterically demanding olefin ligands and were detected only by IR spectroscopy. Prolongated UV irradiation of 2 and ethylene yields in addition to 2a [W(η5:1-C5H 4C2H4)(CO)(η2-C2H4)2] (2a′). Hindered olefin rotations around the metal-olefin bonds were detected for 1a—1c, 1e, 1f, 1i, and 2a with barrieres of activation between 50 to 75 kJ · mol-1.
Diterpenoids from the Root Bark of Azadirachta indica
Authors: Ara Iffat , Siddiqui Bina Shaheen , Faizi Shaheen , Siddiqui Salimuzzaman
Published: March 2015

From the root bark of Azadirachta indica A. Juss (neem) two new diterpenes nimbilicin and nimbocidin have been isolated and their structures established through chemical and spectroscopic methods.
Thermal Decomposition of Lichen Depsides
Authors: Huneck Siegfried , Schmidt Jürgen , Tabacchi Raffaele
Published: March 2015

The thermal decomposition of the following lichen depsides has been described: lecanoric acid, gyrophoric acid, evernic acid, perlatolic acid, planaic acid, confluentic acid, atranorin, 4-O-de-methylbarbatic acid, and sekikaic acid. Main reaction products are decarboxylated compounds, phenolic units, rearranged depsides, and xanthones. Triethylammonium salts of depside carboxylic acids decompose at reasonably lower temperature than the corresponding free acids.
Notizen: A Platinum(II) Complex with a Phosphine Oxide Adduct of Stannous Chloride
Authors: Dodoff Nicolay , Spassovska Nadejda , Varbanov Sabi
Published: March 2015

A platinum(II) complex with an electroneutral adduct of stannous chloride [Pt(Sn(DPPO)Cl2)2Cl2] (DPPO = dimethyl phthalimidomethylphosphine oxide) is synthesized and characterized by infrared and electronic spectra.
Notizen: A New System of Ionophors Derived from o,o′-Biphenyldiol X-Ray Structure of o-Hydroxy-biphenyl-o′-oxyacetamide
Authors: Oh Lin Whei , da Costa J. B. N. , Alt Helmut G. , Rogers Robin D.
Published: March 2015

The synthesis of mono- and diacetamides starting with o,o′-biphenyldiol is described. From o-hydroxy-biphenyl-o′-oxyacetamide an X-ray structure could be obtained.
Spektroskopische Untersuchung des [FCl2V(15N3S2)]--Ions; Kristallstruktur von [Na-Benzo-15-Krone-5][FCl2V(N3S2)] / Spectroscopic Investigation of the Ion [FCl2V(15N3S2)]-; Crystal Structure of [Na-Benzo-15-Crown-5][FCl2V(N3S2)]
Authors: Rehder Dieter , Fenske Dieter , Baum Gerhard , Borgholte Harald , Dehnicke Kurt
Published: March 2015

[Na-15-crown-5][FX2V(N3S2)] (X = Cl, Br) and [Na-benzo-15-crown-5][FCl2V(N3S2)] have been prepared by reactions of X2V(N3S2) with sodium fluoride in acetonitrile suspensions in the presence of 15-crown-5 and benzo-15-crown-5, respectively. The 15N-labeled complex [Na-15-crown-5]-[FCl2V(15N3S2)] was also prepared and characterized by 15N, 19F, and 51V NMR spectra, as well as by IR spectroscopy.

Whereas the crystal structure of [Na-15-crown-5][FCl2V(N3S2)], owing to disorder of the crown ether molecule, could be refined only to an R-value of 0.16 (space group C2/m, Z = 4, a = 1995.4(11); b = 1016.2(6); c = 1047.2(8) pm; β = 100.83(4)° at —65 °C), the crystal structure of the corresponding [Na-benzo-15-crown-5][FCl2V(N3S2)] was determined without complications. Space group P2,/c, Z = 4, 5565 observed independent reflexions, R = 0.036. Lattice dimensions at 20 °C: a = 1198.9(6); b = 970.3(5); c = 1918.2(10) pm; β = 93.74(3)°. The compound forms ion pairs, in which the sodium atom is seven-coordinated by the oxygen atoms of the crown ether molecule, the fluorine atom and one chlorine atom of the trigonal-bipyramidal [FCl2V(N3S2)]- unit. The vanadium atom is part of a planar VN3S2 ring; fluorine and two nitrogen atoms of the cyclothiazeno ring occupy the equatorial positions.
Metallkomplexe funktioneller Isocyanide, XVIII [1]. (Alkylidenamino)carbene durch nucleophile Addition an Pentacarbonylchrom-koordiniertes 1,1-Dichlormethyl-, 1,1,2-Trichlorethyl- und 1-Chlorvinylisocyanid / Metal Complexes of Functional Isocyanides, XVIII [1]. (Alkylideneamino)carbenes by Nucleophilic Addition to Pentacarbonylchromium-coordinated 1,1-Dichloromethyl, 1,1,2-Trichloroethyl and 1-Chlorovinyl Isocyanide
Authors: Fehlhammer Wolf P. , Beck Gerhard
Published: March 2015

Pyrrolidine adds to the isocyano group of Cr(CO)5CNCCl2CH2Cl with concomitant loss of HC1 to give a (1,2-dichloroethylideneamino)(pyrrolidino)carbene complex in which the α-chlorine atom can be replaced by a second molecule of pyrrolidine. Cr(CO)5CNCCl2H (2) and Cr(CO)5CNCCl= CH2 (4) only afford the respective 1:2 adducts, 4 also with diethylamine. 2 and t-butanethiol react with formation of a (t-butylthiomethylidenamino)(t-butylthio)carbene complex (main product) and Cr(CO)5CNCH2Cl (side product). The IR spectra of the carbene species show unusual v(CO) patterns. In order to explain the NMR spectra, three different kinds of hindered rotations and a fast nitrogen inversion are proposed.
Synthesis and Structure of a New Chiral Oxaziridine from (3-Oxo-camphorsulfonyl)imine
Authors: Meladinis Vassilios , Herrmann Rudolf , Steigelmann Oliver , Müller Gerhard
Published: March 2015

Oxidation of (3-oxo-camphorsulfonyl)imine (1) by magnesium monoperoxyphthalate does not lead to the oxaziridine obtained with 3-chloro-perbenzoic acid, but to a new chiral oxaziridine containing an additional oxygen atom (Baeyer-Villiger type oxidation). The structure of the product is established by X-ray crystallography, and reaction pathways for the oxidation of 1 by peracids are discussed.
Factors Affecting Stability and Equilibria of Free Radicals, XVII+ EPR Evidence for Formation of N-Alkoxypicramides on Oxidation of N-Alkoxy-dinitroanilines. Electronic Structure of Aminyl Radicals
Authors: Stănciuc Gabriela , Căproiu Miron T. , Căldăraru Horia , Caragheorgheopol Agneta , Constantinescu Titus , Balaban Alexandru T.
Published: March 2015

Oxidation of N-alkoxy-2,6- or -2,4-dinitroanilines with various oxidizing agents yields the corresponding N-alkoxydinitrophenyl-aminyls, which then undergo spontaneous conversion into the corresponding N-alkoxy-2,4,6-trinitrophenyl-aminyls. The EPR spectra of all these persistent aminyls are presented and discussed. Such disproportionations did not occur in capto-dative diaryl-aminyls which had lower spin densities on the electron-acceptor group than the present N–alkoxy-polynitrophenyl-aminyls (these have, in addition. Ν—Ο bonds which are less strong than N—C bonds). Electronic structures of diaryl-aminyls and N-alkoxy-aryl-aminyls are discussed: both are π-radicals, but they probably possess at the nitrogen atom an approximately linear, and a kinked structure, respectively.
Notizen: Synthesis of Functionalized Acyclic Nitrone Spin Traps
Authors: Zhang Yongkang , Xu Guangzhi
Published: March 2015

Four new spin traps with functionalized acyclic nitrone structures, EtCH(CH2CH2CO2Et)CH=N(O)CMe3(3), EtCH(CH2CH2CH2OH)CH=N(O)CMe3(4), EtCH(CH2CH2CN)CH=N(O)CMe3 (6), EtCH(CH2CH2CO2H)CH=N(O)CMe3 (10), were prepared and characterized by infrared spectrometry, mass spectrometry and 1H NMR.
Raman Spectroscopic Discovery of the Hydrogenthiosulphate Anion, HSSO3
-, in Solid NH4HS2O3 [1]
Authors: Steudel Ralf , Prenzel Andreas
Published: March 2015

Reaction of ammonium thiosulphate with concentrated sulphuric acid in anhydrous methanol at —80°C affords [NH4][HS2O3] the anion of which was shown by Raman spectroscopy to have the structure HSSO3
- (stretching vibrational wavenumbers: SS = 403, SH = 2486, SO = 1027, 1183, and 1219 cm-1; SSH bending mode = 873 cm-1 at —80°C). This salt decomposes at —20°C to give, inter alia, elemental sulfur. The Raman spectra of ND4DS2O3 and (NH4)2S2O3 are also reported.
Gold(I)-Komplexe sekundärer Phosphine / Gold(I) Complexes of Secondary Phosphines
Authors: Schmidbaur Hubert , Weidenhiller Gabriele , Aly Aref A. M. , Steigelmann Oliver , Müller Gerhard
Published: March 2015

Gold(I) complexes with secondary phosphines R2PH (la—d) of the type R2PH · AuCl (2a—d) have been obtained in good yield from reactions of (carbonyl)chlorogold(I) and the corresponding ligand in diethylether. Both compounds 2a, b bearing aromatic substituents with R = 2,4,6-trimethylphenyl (mesityl) and 2-methylphenyl (o-tolyl), and compounds 2c, d with the bulky alkyl substituents R = t-butyl and R = cyclohexyl, resp., are air-stable crystalline solids. — The coordination compounds have been characterized by NMR and IR data, and — in the cases of 2b and 2c — by single crystal X-ray diffraction studies. Crystals of these two compounds are both monoclinic, space group P21/c with four formula units (Z = 4). The analysis shows independent monomers for compound 2c with no intermolecular Au···Au contacts. Molecules of 2b are arranged in centrosymmetrical dimers (head to tail) with an Au···Au distance of 3.56 Å and a dihedral angle P—Au—Au′—P′ of 180°. (This structural study is as yet incomplete and suffers from an unsatisfactory data set for 2b.) It appears that intermolecular contacts are largely controlled by steric effects.
Kristallstruktur von SbF5 · SO2 / Crystal Structure of SbF5 · SO2
Authors: Minkwitz Rolf , Molsbeck Walter , Preut Hans
Published: March 2015

The crystal structure of SbF5 · SO2 is reported. SbF5 · SO2 crystallizes in the monoclinic space group P21/n with a = 580.4(4) pm, b = 1047.7(5) pm, c = 1013.3(6) pm, β = 102.92(5)°, V = 600.57 · 106(6) pm3, and Z = 4. It shows five intermolecular S ··· F contacts.
Notizen: 6-Acetoxy-9-selenabicyclo[3.3.1]-non-2-en: Unerwartetes Produkt der versuchten Se(IV)-Oxidation von 1,5-Cyclooctadien / 6-Acetoxy-9-selenabicyclo[3.3.1]-non-2-en: An Unexpected Product of the Se(IV)-Oxidation of 1,5-Cyclooctadien
Authors: Dehmlow Eckehard V. , Stiehm Thomas
Published: March 2015

Oxidation of 1,5-cyclooctadiene by SeO2/acetic anhydride (or SeO2/dioxane) yields the title compound 2a (or 2b, respectively). The type of reaction is not totally without precedent although the detailed mechanism is still unknown.
Ternäre Nitride des Lithiums mit den Elementen Cr, Mo und W / Ternary Lithium Nitrides with Elements Cr, Mo and W
Authors: Gudat Axel , Haag Sabine , Kniep Rüdiger , Rabenau Albrecht
Published: March 2015

The ternary compounds were prepared by reaction of the transition metals with Li3N melt under nitrogen. The crystal structures of Li6MeN4 (P42/nmc, Z = 2; Me = Mo: a = 667.3(1) pm, c = 492.5(3) pm; Me = W: a = 667.9(1) pm, c = 492.7(1) pm) and Li15Cr2N9 (P4/ncc, Z = 4; a = 1023.3(5) pm, c = 938.9(7) pm) can be described as fluorite-type superstructures with the lithium and transition metal atoms in tetrahedral holes of the nearly fcc nitrogen arrangement and with an ordered distribution of defects within the cation substructure. In addition, the ternary system Li–Cr–N contains the compound Li6CrN4 with a crystal structure which is not quite clear at present, but which shows close relations to the structures of Li6MeN4 (Me = Mo, W). The previously reported compounds Li9MeN5 (Me = Cr, Mo, W) have not been observed during this study. The respective Cr compound in fact is a nitride-oxide (nitride-imide) of composition Li14Cr2N8(O,NH) with a crystal structure (P3̄, Z = 1, a = 579.9(1) pm, c = 826.3(6) pm) also showing a fluorite-type superstructure.
Spaltung der Ylid-Bindung in Phosphor-Yliden: Photolyse von thiophosphoranylsubstituierten (Triphenylphosphoranyliden)methanen / Cleavage of Ylidic Bonds in Phosphorus Ylides: Photolysis of Thiophosphoranyl-Substituted (Triphenylphosphoranylidene)methanes
Authors: Grützmacher Hansjörg
Published: March 2015

The thiophosphoranyl-substituted (triphenylphosphoranylidene)methanes 1, 6a, b are cleaved photolytically (λ > 300 nm, 3 d, 0 °C) to yield triphenylphosphane and the thio-aza-phosphetanes 3 and 8 a, b, b′, respectively. The formation of these heterocycles is explained invoking insertion of the carbenes 2 and 7 a, b into the methine CH bond of one of the isopropyl groups. If 6a is irradiated for 16 h in the presence of the phosphanes P(NMe2)3, P(OMe)3 or P(nBu)3, the new ylides 9 a, b, c are obtained along with small quantities of 8 a. These results indicate a cleavage of the ylidic bond in 1 and 6 a, b. The failure of attempted cyclopropanation reactions of olefins as well as the absence of the expected product of a 1,2-H shift, 10, in the case of the photolysis of 6b leave doubts as to the occurrence of free carbenes.
Fluorosulfonium Hexafluoroarsenate RSF2
+AsF6⁻ / Fluorosulfonium Hexafluoroarsenates, RSF2+AsF6⁻
Authors: Pauer Frank , Erhart Markus , Mews Rüdiger , Stalke Dietmar
Published: March 2015

The crystal structures of Me2NSF2⁺ AsF6⁻ (4) and CF3SF2
+AsF6⁻ (6) are reported and the cation structures compared with those of the corresponding isoelectronic neutral phosphanes.
K20Ga6Sb12,66 und K20Ga6As12,66, Verbindungen mit zu B3O6
3-isostrukturellen Anionen Ga3Sb6
9- und Ga3As6
9- / K20Ga6Sb 12.66 and K20Ga6As12.66, Compounds with Ga3Sb6
9-- and Ga3As6
9--Anions Isostructural to B3O6
3-
Authors: Cordier Gerhard , Ochmann Harald
Published: March 2015

The compounds K20Ga6Sb12,66 and K20Ga6As,12,66 have been prepared from the elements and the crystal structures were determined by single crystal X-ray diffraction a = 1780.0(5), (1678.0(5)) pm, c = 543.8(2), (524.5(2)) pm, P63/m, Z = 4. The structures contain oligomeric anions Ga3As6
9- and Ga3Sb6
9-, which are isoelectronic to B3O6
3-
Nachweis starker C – Sn-Hyperkonjugation über Kristallstruktur und NMR-Daten eines C-Stannylmethylenborans / Evidence for Strong C–Sn-Hyperconjugation by Crystal Structure and NMR Data of a C-Stannylmethyleneborane
Authors: Allwohn Jürgen , Hunold Ralf , Pilz Monika , Müller Rolf-Günter , Massa Werner , Berndt Armin
Published: March 2015

Strong C—Sn hyperconjugation in C-stannylmethyleneborane 3 is indicated by (1) a small B—sp2C—Sn bond angle (105.6°), (2) a long sp2C—Sn bond (216 pm), (3) a very short B=C double bond (131 pm), (4) a very small coupling constant 1J(119Sn-13C) = 125 Hz for the sp2C—Sn bond and (5) shielding of the boron atom of the B=C double bond by 20 ppm as compared to methyleneboranes without strong hyperconjugation. The boron atoms of the B=C double bond of 3 and related methyleneboranes act as π-donor and σ-acceptor, the substituents X at the carbon atom of the B=C double bond as π-acceptors and, through their C—X σ-bonds, as σ-donors. The partly bridged methyleneborane 3 closes the gap between unbridged and bridged methyleneboranes. Relationships to non-classical carbocations are pointed out.
μ-5,8-Dioxido-1,4-naphthochinon(2–)-O,O″′; O′,O″ ]bis-[tetraphenylantimon(V)]-Dioxan (3/5) / [,u-5,8-Dioxido-l,4-naphthoquinone(2–)-O,O″′; O′,O″]bis[tetraphenylantimony(V)] Dioxane (3/5)
Authors: Arnold Susanne , Mansel Volker , Klar Günter
Published: March 2015

The title compound is prepared from naphthazarine (5,8-dihydroxy-1,4-naphthoquinone) and tetraphenylstibonium ethoxide (molar ratio 1:2) in dioxane as a solvent. X-ray analysis shows the naphthazarine dianion to act as a bifunctional chelating ligand in which two 2,2′-connected 1,3-diketonato groups are fixed in a coplanar position by two cis-ethenediyl bridges. The interaction of the naphthazarine dianion with the tetraphenylstibonium ions is an intermediate between ionic and covalent bonding. Consequently the antimony ions have strongly distorted octahedral coordination spheres (Sb–O 225,5(4) pm, Sb–Ce 215,9(6) pm, Sb–Ca 214,8(5) pm; O-Sb-O 75,9(1)°, Ce– Sb– Ce 103,8(2)°, Ca–Sb–Ca 166,0(2)°). The chelate rings are folded at the O/O axes (angles of fold 20-36°), the two antimony centers being arranged in trans-positions relative to the plane of the naphthazarine dianion.
Optical Resolution of Racemic Jasmonic Acid by Separation of Diastereomeric Mandelyl Esters
Authors: Kramell Robert , Schneider Gernot , Schmidt Jürgen , Sembdner Günther , Schreiber Klaus
Published: March 2015

The reaction of racemic jasmonic acid with either (R)-mandelic acid or its (S)-enantiomer resulted in a mixture of diastereomeric esters. Both the O-[(±)-jasmonoyl]-(R)-mandelic acids (2a, 2b) and the O-[(±)-jasmonoyl]-(S)-mandelic acids (3a, 3b) could be separated by silica gel chromatography. By hydrolysis of the pure diastereomers, resolved (+)-JA (la) and (–)-JA (lb) were obtained. The structures and the purity of all compounds were confirmed by 1H NMR, MS, GC/MS, IR and ORD.
Fluorierte α-Oxocarbonsäuren aus Oxalsäuredi-tert-butylester und fluorierten (Halo)alkyltrimethylsilanen / Fluorinated a-Oxocarboxylic Acids from Oxalic Di-tert-butylester and Fluoro(halo)alkyltrimethylsilanes
Authors: Broicher Volker , Geffken Detlef
Published: March 2015

An efficient two-step synthesis of some fluoro pyruvic acids monohydrates 6 is described. The reaction of fluoromethyltrimethylsilanes 3 with di-tert-butyl oxalate (4) in the presence of tetrabutylammonium fluoride as a catalyst produces intermediate siloxy products 5, which are converted by hydrogen chloride into 6. 3,3,4,4,4-Pentafluoro-2-oxo-butanoic acid monohydrate (6c) is obtained analogously by reacting pentafluoroethyltrimethylsilane (3c) with 4.
Synthese und NMR-Spektroskopie von 2,5-diborylierten 3-Plumbolenen und 3-Stannolenen / Synthesis and NMR Spectroscopy of 2,5-Diborylated 3-Plumbolenes and 3-Stannolenes
Authors: Wrackmeyer Bernd , Horchler Klaus
Published: March 2015

The organoboration of bis(alkynyl)plumbanes (1) leads to intermediates 7 in which a triorganolead cation is stabilized by intramolecular side-on coordination to the C=C triple bond of an alkynylborate function. These compounds decompose rapidly at room temperature or rearrange to give 1,4-plumbabora-2,5-cyclohexadienes (10). If the compounds 7 are treated with an excess of trialkylborane (2) they are converted into bis(alkenyl)lead derivatives (8) as the final products (8c, 8ca) or again as intermediates for the 2,5-bis(dialkylboryl)-3-plumbolenes 9. A mechanism suggested for the formation of 9 is based on the product distribution (9ab/9ba = 2:1) obtained from the reaction of a distinct compound 7a with different trialkylboranes (2a, 2b). All compounds have been fully characterized by multinuclear magnetic resonance data (1H, 11B, 13C, 207Pb), dynamic NMR and two-dimensional (2 D) NMR techniques. In addition, these techniques have been applied to some of the analogous tin compounds (e.g. 4b, 5).
Darstellung und spektroskopische Charakterisierung von Nitridophthalocyaninatomangan(V) / Preparation and Spectroscopical Characterization of Nitridophthalocyaninatomanganese(V)
Authors: Grunewald Horst , Homborg Heiner
Published: March 2015

Nitridophthalocyaninatomanganese(V), MnNPc(2–), has been prepared by oxidation of [Mn(OH)2,Pc(2–)]- with chlorine in the presence of excess ammonia in dichloromethane as a chemically very stable, diamagnetic microcrystalline blue powder. The band at 1053 cm-1 in the infrared and resonance Raman spectra is assigned to v(Mn=N). The strong resonance enhancement of v(Mn=N) coincides with an electronic transition at 461 nm assigned to (N → Mn) electron transfer. The UV-VIS spectrum in 1-chloronaphthalene is compared with that of the MnNPc(2–)–H2SO4 adduct and the phthalocyanine-π-cation radical [MnNPc(1–)]+.
Darstellung und Charakterisierung der μ3-Oxo-Cluster [Cp3Mo3(CO)4µ-Cl)(µ3-O)] und [Cp3Mo3(µ-CO)3(CO)3(µ3-O)]+ / Synthesis and Characterization of the µ3-Oxo Clusters [Cp3Mo3(CO)4μ-Cl)(μ3-O)] and [Cp3Mo3(μ-CO)3(CO)3(μ3-O)]+
Authors: Nuber B. , Schatz W. , Ziegler M. L.
Published: March 2015

[CpMo(CO)3]2 (1) (Cp = cyclopentadienyl) reacts with InCl3 in diglyme to yield the oxo-cluster [Cp3Mo3(CO)4(μ-Cl)(μ3-O)] (2) and the cationic oxo-cluster [Cp3Mo3(μ-CO)3(CO)3(μ3-O)]+ as the salt [Cp3Mo3(μ-CO)3(CO)3
(μ3-O)][CpMo(CO)3InCl3] (3). The compounds were characterized by elemental analysis, spectroscopic data and X-ray structure analysis. Compound 2 crystallizes in the orthorhombic space group P212121 with a = 1006.0(3), b = 1244.6(4) and c = 1600.8(5) pm, V = 2004.3 x 106 pm3, Z = 4. Compound 3 crystallizes in the monoclinic space group P 21/m with a = 874.4(8), b = 1407(1) and c = 1500(1) pm, β = 92.95(6) , V = 1843 × 106 pm3, Z = 2.
Secondary Metabolites by Chemical Screening, 3 [1] Side-Chain Modification of Elaiophylin
Authors: Hammann Peter , Kretzschmar Gerhard
Published: March 2015

Base catalyzed deglycosidation of elaiophylin leads to a reactive enone system. Following addition of thiols yield side-chain modified products of the title compound.
Metallkomplexe mit Tetrapyrrol-Liganden, LVI [1] / Metal Complexes with Tetrapyrrole Ligands, LVI [1]
Authors: Buchler Johann W. , Löffler Jürgen
Published: March 2015

The reaction of tris(2,4-pentanedionato)europium(III) with a porphyrin H2(P)** in boiling 1,2,4-trichlorobenzene affords a so-called “redox mixture” of europium(III) bisporphyrinates, i. e. porphyrin π-radicals of the type Eu(P)2 and sandwiches EuH(P)2 in which one of the porphyrin rings is protonated. Thus, from either tetraphenylporphyrin or its dilithium derivative, or octaethylporphyrin, or a mixture of both porphyrins, the corresponding mixtures of double-deckers with two identical or two differnt porphyrin rings are obtained. The transformation of the redox mixtures into the pure tetraphenylporphyrin derivatives Eu(TPP)2, EuH(TPP)2, and the salt [NBu4] [Eu(TPP),, the separation of the octaethylporphyrin derivatives Eu(OEP)2 and EuH(OEP)2, and the purification of the “mixed” double-decker Eu(OEP)-(TPP) are described. The compounds are characterized by cyclic voltammetry, IR, UV/VIS/NIR, 1H NMR, and mass spectra. The obtained data indicate that the π-electrons of the two porphyrin rings behave as a common electronic system in which a defect electron is delocalized. However, in the “mixed” double-decker Eu(OEP) (TPP) the defect electron is more concentrated on the OEP ring, i. e. the porphyrin ring which is more easily oxidized.
Synthesis and Stereoselective Glycosylations of 3-O-Acetyl-2,4-O-phenylboranediyl-β-D-ribopyranosyl Bromide
Authors: Dahlhoff Wilhelm V. , Schroth Gerhard , Gabor Barbara , Köster Roland
Published: March 2015

Crystalline 3-O-acetyl-2,4-O-phenylboranediyl-β-D-ribopyranosyl bromide (5) is prepared by an easy four-step synthesis from D-ribose (1), the first three steps of which are realised in an one-pot manner. 5 reacts stereoselectively with sodium methoxide and phenoxide to give the pure methyl and phenyl a-D-ribopyranosides 7 a and 7 b after deboronation and deacetylation.
Notizen: Synthesis of Isopropoxy-Chloro-Disulfane (ROSSCl) and its Reaction with Titanocene Pentasulfide to Give (RO)2S9
Authors: Schmidt Heinar , Steudel Ralf
Published: March 2015

Bis-alkoxy-disulfanes, ROSSOR, react with SCI, at 0 °C to give ROSSCl which yield the corresponding nonasulfanes, RO—S9—OR, on reaction with titanocene pentasulfide, (C5H5)2TiS5. Raman, mass, and NMR spectra of ROSSCl and (RO)2S9 (R = isopropyl) are reported.
Zur Stereochemie des freien Elektronenpaares in AX6E-Systemen, IX+ Statisch verzerrtes Anion in [(CH3)2HN(C6H4)NH(CH3)2]TeCl6 / On the Stereochemistry of the Lone-Pair Electrons in AX6E-Systems, IX+ Statically Distorted Anion in [(CH3)2HN(C6H4)NH(CH3)2]TeCl6
Authors: du Bois André , Abriel Walter
Published: March 2015

Using 293 K diffractometer intensity data, the crystal structure of [(CH3)2HN(C6H4)NH(CH3)2]TeCl6 has been determined by single crystal X-ray technique and refined to a final Rw of 0.022. The yellow crystals are orthorhombic, space group Pna 21, with a = 17.565(2), b = 8.4496(6), c = 12.572(1) Å and Z = 4. The TeCl6
2- anions show a strong statical distortion with Te—Cl distances from min. 2.39 to max. 2.78 A. The symmetry rules for the stereochemistry of the lone pair electrons in AX6E-systems are confirmed. The influence of hydrogen bonding on the type of distortion is also discussed.
Optisch aktive Übergangsmetall-Komplexe, 97 [1] C5H5Fe(CO)(COMe)-Derivate von Glyphos und Diop / Optically Active Transition Metal Complexes, 97 [1] C5H5Fe(CO)(COMe) Derivatives of Glyphos and Diop
Authors: Brunner Henri , Eder Rudolf
Published: March 2015

The reaction of CpFe(CO)2Me with (+)-Glyphos and (–)-Diop yields the monosubstitution products 1 and 2, which consist of pairs of diastereomers, differing only in the Fe configuration. With (–)-Diop, additionally dinuclear complexes are formed in which Diop acts as a bridging ligand. The diastereomers can be separated by column chromatography. At higher temperatures the complexes epimerize in solution with respect to the Fe configuration. The formation of free phosphine and CpFe(CO)2Me indicates a dissociative mechanism.
Zur Polymorphie des Ba(BrO3)2 und Sr(IO3)2, Kristallstruktur, röntgenographische, schwingungsspektroskopische und thermoanalytische Untersuchungen / Polymorphism of Ba(BrO3)2 and Sr(IO3)2 — Crystal Structure, X-Ray, IR, Raman, and Thermoanalytical Data
Authors: Lutz Heinz Dieter , Alici Ekrem , Kellersohn Thomas , Kuske Peter
Published: March 2015

The polymorphic behaviour of Ba(BrO3)2 and Sr(IO3)2 is studied by means of differential thermal analyses and high-temperature X-ray and Raman spectroscopic measurements. On dehydration of the respective monohydrates [Ba(ClO3)2 · H2O type] at low temperatures in a vacuum Ba(BrO3)2 I and α-Sr(IO3)2 (both α-Ba(IO3)2 type, space group C2/c, Z = 4) are formed. On heating these polymorphs above 145 and 240 °C, respectively, phase transitions to Ba(BrO3)2 II [Sr(ClO3)2 type] and the hitherto unknown γ-Sr(IO3)2 occur. On further heating Ba(BrO3)2 II decomposes [partly via the high-temperature polymorph Ba(BrO3)2 III] to BaBr2 and O2, γ-Sr(IO3)2 via the probably only stable polymorph β-Sr(IO3)2 to iodine and strontium paraperiodate. The IR and Raman spectra of Ba(BrO3)2 I and III, α-, β- and γ-Sr(IO3)2, and α-Ba(IO3)2 are given. The crystal structure of Ba(BrO3)2 I has been determined by single crystal X-ray diffraction. The final R value for 1586 reflections with I ≥ 2σI is 0.064. The crystal structures of the a-Ba(IO3)2 type anhydrous halates are very similar to those of the Ba(ClO3)2 · H2O type halate monohydrates.
Die Ligandeneigenschaften der Komplexe LMO3 (M = Mo(VI), W(VI), L = cyclisches Triamin). Die Kristallstrukturen von [(LMoO3)4Co][BPh4]2 · C2H5OH, (LMoO3)4Fe][BPh4]3 · NaBPh4, [LWO3BPh3] und [(LWO3)2BPh2][BPh4] / The Ligating Properties of LMO3-Complexes (M = Mo(VI), W(VI), L = Cyclic Triamine). The Crystal Structures of [(LMoO3)4Co][BPh4]2 · C2H5OH, [(LMoO3)4Fe][BPh4]3 · NaBPh4, [LWO3BPh3] and [(LWO3)2BPh2][BPh4]
Authors: Schreiber Peter , Wieghardt Karl , Nuber Bernhard , Weiss Johannes
Published: March 2015

The reactivity of LMO3 and L′MO3 complexes as ligands has been investigated (L = C6H15N3, 1,4,7-triazacyclononane; L′ = C9H21N3, N,N′,N″-trimethyl-1,4,7-triazacyclononane; M = MoVI, WVI).

The crystal structures of [(L′MoO3)4CoII][BPh4]2· C2H5OH (1) and [(L′MoO3)4FeIII][BPh4]3· Na[BPh4] (2) have been determined by X-ray crystallography. Both the CoII and FeIII centers are in a tetrahedral environment of four oxygen atoms which are connected to L′MO2 fragments. The reaction of LMO3 complexes (M = MoVI, WVI) in aqueous solution with tetraphenylborate(1–) anions yields LMO3BPh3 or [(LMO3)2BPh2][BPh4] complexes and benzene. The crystal structures of LWO3BPh3 (3) and [(LWO3)2BPh2][BPh4] (4) have been determined.
Luminescence of the Red Modification of Single-Crystal Pt(bpy)Cl2 (bpy: 2,2′-Bipyridine)
Authors: Weiser-Wallfahrer M. , Gliemann G.
Published: March 2015

The polarized optical emission (energy, intensity, lifetime) of the red modification of singlecrystal Pt(bpy)Cl2 as a function of temperature (1.9 ≤ T ≤ 298 K) and homogeneous magnetic fields (0 ≤ H ≤ 6 T), and the temperature dependence of the polarized optical absorption are reported. Analysis of the spectra indicates a strong inter-complex coupling giving rise to electronic band structures and self-trapped states.
Synthese und Strukturuntersuchungen von Iodocupraten(I) XII. [(DMF)2H]∞
1Me3X4]-Halogenometallate(I) mit neuartigen Tetraederdreifachketten [1] / Syntheses and Structure Analyses of Iodocuprates(I) XII. [(DMF)2H]∞
1[Me3X4]-Halometallates(I) with New Tetrahedratriple Chains [1]
Authors: Frydrych Roman , Muschter Thomas , Brüdgam Irene , Hartl Hans
Published: March 2015

N,N-Dimethylformamidinium-halometallates(I), [(DM F)2H][Me3X4] with Me3X4 = Cu3I4
-, Cu3I2Br2
-, Cu3I3Cl-, Ag2CuI4
-, Ag3I4
-, Ag3I3Br- and Ag3I3Cl- were obtained by reacting Cul or Agl with HI, HBr or HC1 in DMF. The crystal structures of the isostructural compounds (space group Pccn) are built by hydrogen-bridged DMF molecules, (DMF)2H+, as cations and a new type of polymeric anion formed by edge sharing tetrahedra triple chains. The chains consist of a double layer of halogen atoms where Cu(I) and Ag(I) cations are located in tetrahedral holes. There are two kinds of halogen positions in the chains. One of them bridges two metal ions, the other is coordinated by four metal ions. In the anion chains ∞
1,[Cu3I2Br2
-], ∞
1[Cu3I3Cl-], ∞
1[Ag3I3Br-] and ∞
1[Ag3I3Cl-] the lighter halogen atoms occupy the positions bridging two metal ions. The O—H—O distances range from 235-243 pm. They indicate strong hydrogen-bonding between the two DMF molecules in the (DMF)2H+ cations.
(PPh4)2[Mn(Se4)2]; Synthese und Kristallstruktur / (PPh4)2[Mn(Se4)
2]; Synthesis and Crystal Structure
Authors: Kräuter Gertrud , Ha-Eierdanz MyLinh , Müller Ulrich , Dehnicke Kurt
Published: March 2015

(PPh4)2[Mn(Se4)2] has been prepared by the reaction of a lithium poiyseienide solution in DMF with MnCl2.4H2O at 100 °C in the presence of PPh4Br. The compound forms black crystals, which were characterized by IR spectroscopy as well as by an X-ray structure determination. Space group P21, Z = 4, 3622 observed unique reflexions, R = 0.076. Lattice dimensions at 19 °C: a = 1017.2(3), b = 1405.9(3), c = 3427.7(8) pm, β = 92.04(2)°. The compound consists of PPh4⁺ and [Mn(Se4)2]2- ions, in which the manganese atom is tetrahedrally surrounded by four selenium atoms of two chelating Se4
2- units. The structure is isotypical with that of (PPh4)2[Zn(Se4)2].
Reaction of N-Arylphthalisoimidium Perchlorates with Amines and Aromatic Hydrocarbons under Friedel-Crafts Conditions, a New and Convenient One-Step Method for the Synthesis of 2,3-Diaryl-3-hydroxyphthalimidines
Authors: Ismail M. Fekry , Enayat E. I. , El-Bassiouny F. A. , Younes H. A.
Published: March 2015

N-Arylphthalisoimidium perchlorates (1 a, b) react with primary amines via ring-opening to give N,N′-disubstituted phthalamides (3a—d). They react with aromatic hydrocarbons under Friedel-Crafts conditions to give 2,3-diaryl-3-hydroxyphthalimidines (a—i) while the reaction of 1 a with phenylmagnesium bromide involved just deprotonation to the isoimide (9) followed by rearrangement to N-phenylphthalimide (8).
An Improved Preparation of 11,19-Oxidopregn-4-ene-3,20-dione and 6,19-Oxidopregn-4-ene-3,11,20-trione
Authors: Brachet-Cota Adriana L. , Burton Gerardo
Published: March 2015

A synthesis of 11,19-oxidopregn-4-ene-3,20-dione and 6,19-oxidopregn-4-ene-3,11,20-trione is described starting from pregn-4-ene-3,11,20-trione and via the common intermediate 3β,20β-diacetyloxy-5α-bromo-6,19-oxidopregnan-11-one, in 30 and 32% yield, respectively.
Notizen: CNDO/S-CI-nPDQ Studies of the Solvation Effect on the UV Spectra of Pyridine N-Oxide and its Complexes with Proton
Authors: Chmurzyński Lech , Liwo Adam , Wawrzynów Alicja , Tempczyk Anna
Published: March 2015

Using the n-PDQ model, in which the solvent is simulated by several point dipoles and quadrupoles, we have estimated the shift of the UV bands of pyridine N-oxide (PyO), its cationic acid (PyOH+), and homoconjugated cation (PyOHPyO+) caused by the solvent (acetonitrile). We have calculated the UV spectra of both unsolvated and solvated species by the CNDO/S-CI and CNDO/S-CI-nPDQ method, respectively. We have found that all the bands of all the species under study are blue-shifted on solvation. The most significant is the shift of the long-wave π→π* bands of pyridine N-oxide.
Germanium(II)-Komplexe mit Dithio-at-Chelatliganden / Germanium(II) Complexes with Dithio-ate Chelating Ligands
Authors: Karsch Hans H. , Hollstein Michael , Müller Gerhard
Published: March 2015

Stable germanium(II)-dithiocarbamate complexes Ge[S2C(NR2)]2 (R = Me, Et) have been obtained from GeCl2 · dioxane and Na[S2C(NR2)]. As an intermediate, Ge(Cl)[S2C(NEt2)] also could be isolated. Likewise, Ge[S2PMe2]2 was synthesized from GeCl2 · dioxane and Na[S2PMe2] and characterized by X-ray structure analysis. The germanium atom acts as a spiro-center for four sulfur atoms in a distorted ψ-trigonal bipyramidal configuration which is established by two anisobidentate dithiophosphinate ligands. The axial Ge—S bonds are significantly longer (mean: 2.722 A) than the equatorial ones (mean: 2.415 A). The variation in the axial bonds is more pronounced (0.058 A) than in the equatorial (0.013 A) Ge—S bonds, but this effect is much smaller than in the comparable Ge[(PMe2)2CPMe2]2 complex.
Silaethene, XIV [1] Bildung und Reaktivität von 1,1-Di-tert-butoxy-2-neopentylsilaethen (tBuO)2Si = CHNp / Silaethenes, XIV [1] Formation and Reactivity of 1,1-Di-tert-butoxy-2-neopentyl Silaethene (tBuO)2Si=CHNp
Authors: Grobe Joseph , Schröder Helmut , Auner Norbert
Published: March 2015

The reaction of (tBuO)2Si(Cl)Vi (3) with LitBu has been investigated in pentane or toluene (non-polar) and mixtures of pentane or toluene with THF (polar), respectively, in order to gain information about the influence of substituents and the polarity of the solvent on the reaction mechanism. In accord with earlier results, using Me2Si(Cl)Vi (1) [8] ortBu2Si(Cl)Vi (2) [5] as precursors, the course of reaction in non-polar solvents is dominated by 1,2-elimination of LiCl from the α-lithio intermediate R2Si(Cl)CH(Li)CH2HtBu yielding 1,1,3,3-tetra(tertbutoxy)-1,3-disilacyclobutane (4) via the corresponding silaethene derivative. On the other hand, the presence of small amounts (5% by volume) of THF in the solvent system leads to a considerable decrease in the yield of 4 and favours secondary reactions of the α-lithio derivative by solvate formation giving chain compounds like (tBuO)2Si(X)CH2CH2
tBu (X = Cl, tBu) and (tBuO)2Si(CH=CHtBu)Si(OtBu)2CH2CH2
tBu (5b). MNDO calculations on the model compounds Me2Si=CH2, Me2Si=CH2 · OH2 and (HO)2Si=CH2, (HO)2Si=CH2 · OH2, respectively, show that for the gas phase molecules the formation of the dimethyl derivatives from the corresponding α-lithio intermediate is less endothermic than that of the dihydroxy analogues. Therefore, the differences observed in the product pattern of the reactions of 1 and 3, respectively, especially in polar systems, can only be explained by a combination of substituent and solvent effects on the kinetics.
Bicyclo[3.2.1]octa-2,6-dienyllithium and -potassium Chemistry Solvation, Aggregation, and 119Sn-7Li Coupling of Stannylated Derivatives
Authors: Hertkorn Norbert , Köhler Frank H.
Published: March 2015

The 13C NMR spectra of bicyclo[3.2.1]octa-2,6-dienyl anion (1) as the lithium (1 Li) and the potassium salt (1 K) were recorded at various temperatures and in different solvents. The results show 1K to exist as a contact ion pair (CIP), whereas for 1 Li solvent separated ions (SSIP) are also found as the temperature is lowered and when the solvating power of the solvent is increased. In the 7Li NMR spectra at very low temperature the signals of the SSIP disappear and only those of a monomeric CIP and a triple ion (1 Li 1) consisting of two carbanions and one lithium cation are present. For independent confirmation, the hitherto unknown 6-, 7-, and 3-trimethylstannyl substituted bicyclo[3.2.1]octa-2,6-dienyllithium derivatives 2 a Li, 2 b Li, and 3 Li were synthesized and also studied by 119Sn, 13C, and 1H NMR. According to the temperature dependence of the δ(13C)-values the CIP/SSIP-equilibrium of 2 a Li in THF/TMEDA is shifted to the CIP side. The observation of a unique 119Sn-7Li coupling (6.2 Hz) shows that at –90 °C a species containing 2 a and lithium exists under slow exchange conditions. A similar coupling of 3.5 Hz can be estimated for 3Li. A mixture of the epimeric carbanions 2a and 2 b yields two sets of 13C NMR signals which are due to the diastereomeric triple ions 2 aLi 2 a and 2 aLi 2 b.
Characterization of Photochemically or Electrochemically Reduced Blue Titanium Dioxide
Authors: Muller R. P. , Steinle J. , Boehm H. P.
Published: March 2015

Blue TiO2 which is formed under UV irradiation under inert gases in the presence of hole scavengers is characterized. The concentration of surface-trapped electrons which cause the blue colour was analytically determined after irradiation in the presence of methanol or other organic compounds. The saturation concentration is controlled by a dynamic equilibrium of photoreduction and reoxidation of the reduced surface sites which leads to H2 formation. The blue colour can also be produced by chemical or electrochemical reduction. Mobility of the surface-trapped electrons in an electrical field gradient is demonstrated. The reduced TiO2 is similar to a hydrogen titanium bronze.
Darstellung und Struktur kationischer η2-Thiocarbenkomplexe von Molybdän und Wolfram / Synthesis and Structure of Cationic η2-Thiocarbene Complexes of Molybdenum and Tungsten
Authors: Ullrich N. , Stegmair C. , Keller H. , Herdtweck E. , Kreißl F. R.
Published: March 2015

The reaction of dimethyl(methylthio)sulfonium tetrafluoroborate [(CH3)2S–SCH3][BF4] with η/5-cyclopentadienyl(dicarbonyl)carbyne complexes of molybdenum and tungsten Cp(CO)2M ≡ C–R (M = Mo, W; R = CH3, C6H5, C6H4CH3) 1c, 2a–d results in an electrophilic attack of the SCH3 moiety at the metal carbon triple bond, providing orange to red, diamagnetic, cationic η2-thiocarbene complexes

3c, 4a–d in high yields. The new compounds were identified by X-ray structure analysis, NMR, IR and mass spectra.
Einkristallzüchtung und Röntgenstrukturanalyse der Fluoridcarbonate K3CO3F und Rb3CO3F / Crystal Growth and X-Ray Structure Determination of the Fluoride Carbonates K3CO3F and Rb3CO3F
Authors: Arlt Joachim , Jansen Martin
Published: March 2015

The isostructural title compounds have been characterized by X-ray powder and single crystal diffraction: R 3̅ c; Z = 6; a = 741.81(4), c = 1639.18(9) pm; 389 diffractometer data, R = 0.04, Rw = 0.03 (K3CO3F); α = 776.1(3), c = 1741.2(9) pm; 235 diffractometer data, R = 0.07, R = 0.06 (Rb3CO3F). Both compounds are carbonate fluorides with isolated CO3
2- and F- anions.
Zur Reaktion von [{ Cp(CO)2Fe} 2SnCl2] mit Bis(trimethylsilyl)selenan und -sulfan. Die Kristallstrukturen von [{Cp(CO)2Fe}4Sn2Se2], [{Cp(CO)2Fe}4Sn4Se6] und [Cp4(CO)7Fe4Sn3S4] / Reaction of [{Cp(CO)2Fe}2SnCl2] with Bis(trimethylsilyl)selenane and -sulfane. The Crystal Structures of [{Cp(CO)2Fe}4Sn2Se2], [{Cp(CO)2Fe}4Sn4Se6] and [Cp4(CO)7Fe4Sn3S4]
Authors: Merzweiler Kurt , Weisse Laurent
Published: March 2015

[{Cp(CO)2Fe}2SnCl2] (1) reacts with (Me3Si)2Se to form the compounds [{Cp(CO)2Fe}4Sn2Se2] (2) and [{Cp(CO)2Fe}4Sn4Se6] (3). The structures of 2 and 3 were determined by X-ray structure analysis. 2 contains a four-membered Sn2Se2 ring. In 3 an adamantane-like Sn4Se6 cage is observed. The reaction of [{Cp(CO)2Fe}2SnCl2] with (Me3Si)2S leads to [Cp4(CO)7Fe4Sn3S4] (4) a compound with a tricyclic Sn3S4Fe cage.
Synthese und Struktur von 1,2-Bis(diisopropylamino)-1,2-diboretan / Synthesis and Structure of 1,2-Bis(diisopropylamino)-1,2-diboretane
Authors: Krämer Albrecht , Uhm Jae-Kook , Garner Stephanie E. , Pritzkow Hans , Siebert Walter
Published: March 2015

Substitution of two chlorine atoms in 1,2-bis(dichloroboryl)ethane with diisopropylamine yields 1,2-bis(chlorodiisopropylaminoboryl)ethane (4), which is reacted with Na/K alloy to give 1,2-bis(diisopropylamino)-1,2-diboretane (5) in 91% yield. 5 crystallizes in the space group P 21/c with the lattice constants a = 6.116(1), b = 16.658(5), c = 17.577(4) Å, β = 99.49(2)°.
A Study on the Mannich Reaction with 1,3-Indandione
Authors: Afsah E. M. , Hammouda M. , Khalifa M. M.
Published: March 2015

Attempted Mannich reaction with the title compound 1 using morpholine and formalin led to 2 or 4 according to the reaction conditions. Whereas, on using primary amines the diindeno [1,2-b:2′,1′-e]pyridine (9-11) were obtained, in addition to 2-methylene-1,3-indandione (6), in case of 10 and 11.

However, the Mannich bases 13-15 were formed on treating 2-benzylidene-1,3-indandione with the appropriate secondary amine. The structures 2, 9-11 were confirmed via unambiguous syntheses.