bluuebunny/crossref_metadata_2025 huggingface dataset:
Notizen: Cadabicilone, a Sesquiterpene Lactone from Cadaba farinosa
Authors: Ahmad Viqar Uddin , Amber Aziz-ur-Rehman , Fizza Kaniz , Kamal Arshad
Published: March 2015

A new eudesmanolide has been isolated from Cadaba farinosa. Its structure was determined by spectroscopic studies including 2 D-NMR (J-resolved, COSY-45 and hetero COSY experiments).
Notizen: A Novel Triterpenoid Isolated from the Roots of Glycyrrhiza echinata L.
Authors: Mirhom Y. W. , Hanna A. G. , Elgamal M. H. A. , Szendrei K. , Reisch J.
Published: March 2015

3β,21 α-dihydroxy-oleane-11,13-dien-28-oic acid was isolated from the roots of Glycyrrhiza echinata L. and its structure was elucidated by spectral analysis.
Synthese von Diboraheterocyclen mit einer BC3B-Gruppierung / Synthesis of Diboraheterocycles with a BC3B Unit
Authors: Knörzer Gabriele , Seyffer Hermann , Siebert Walter
Published: March 2015

Double hydroboration of allene with HBCl2 · OEt2/BCl3 leads to 1,3-bis(dichloroboryl)-propane 1 a, in which two chlorine atoms can be substituted by HN(iPr)2 to give 1 b. Dehalogenation of 1 b with Na/K alloy yields the 1,2-diborolane 2b. Attempts to synthesize an unsaturated 2,3-dihydro-1,2-diborole 4 failed. 1 a and (Me3Si)2S react to give the 1,2,6-thiadiborinane 6 a, and 1 b and Me3C – NH2 yield the 1,2,6-azadiborinane derivative 7b.
Kontraktionsreaktionen lithiierter Cyclotetrasilazane zu Cyclotri- und Cyclodisilazanen / Contraction Reactions of Lithiated Cyclotetrasilazanes Yielding Cyclotri- and Cyclodisilazanes
Authors: Dippel Kerstin , Klingebiel Uwe
Published: March 2015

The lithium derivate of the octamethylcyclotetrasilazane 1 reacts with fluorosilanes with substitution (2) or substitution and contraction to give cyclotrisilazanes (3—6). Lithiated 6 again reacts with substitution (7, 11, 12) or substitution and isomerization to give 1,3-(Si–N–Si) substituted cyclodisilazanes (8, 13). Starting with the dilithiated eight membered ring (14) the reactions with fluorosilanes lead to the formation of the unsymmetrically 1-(Si)-3-(Si – N – Si – N –Si)-substituted four membered rings (9, 10). The isomerization of the lithium salts depends on thermal, thermodynamic and kinetic effects.
Sborgit und β-Sborgit — eine zweite synthetische Modifikation von Na[B5O6(OH)4] · 3 H2O / Sborgit and β-Sborgit – a Second Synthetic Modification of Na[B5O6(OH)4] · 3 H2O
Authors: Timper Ulrich , Heller Gert , Shakibaie-Moghadam Mahmood
Published: March 2015

In crystallization experiments for silver borate hydrates from solutions of borax, boric acid, and silver nitrate, a mixture of sborgite and a second modification — named by us “β-sborgite” — have been found besides excess H3BO3 and a microcrystalline silver borate. Both modifications contain the same distorted pentaborate ion [B5O6(OH)4]-. Both Na+ ions in the asymmetric unit are in special positions along the binary axis; one, Na(1), is octahedrally coordinated by four H2O molecules and two OH groups, the other one, Na(2), is tetrahedrally coordinated by two H2O molecules, two OH groups and — at longer distances — with two bridging oxygen atoms of the pentaborate unit. The different angles — only a small rotation on the b-axis — of the pentaborate anions between an identical matrix of Na-cations give rise to the two different modifications.
Notizen: Cyclophanes, XXXIV [1]
Authors: Jones Peter G. , Bodwell Graham , Hopf Henning
Published: March 2015

The title compound 3 was prepared by pyrolysis of the corresponding bis-sulfone 2 and subjected to X-ray structural analysis; space group P 1̅, a = 477.0(1), b = 625.6(2), c = 1363.6(3) pm, α = 82.79(2), β = 83.43(2), γ = 78.18(3)°, Ζ = 1, R = 0.058 for 900 reflections. The molecule contains a crystallographic symmetry centre, thus confirming the anti configuration.
Darstellung und Kristallstruktur der Verbindungen SEPdP (SE = Seltenerdelement) / Preparation and Crystal Structure of SEPdP Compounds (SE = Rare Earth Element)
Authors: Johrendt Dirk , Mewis Albrecht
Published: March 2015

The new compounds SEPdP (SE = La—Gd), which were prepared by heating the elements, crystallize with a modified Ni2In-type structure. The phosphides of SE = Dy—Lu attain the orthorhombic TiNiSi-type structure. A comparison of the cell volumes suggests that europium has intermediate valence in EuPdP.
Koordination von Diazoverbindungen an Cobalt(I)-Zentren / Coordination of Diazo Compounds to Cobalt(I) Centres Struktur von Methyl(diazocyclopentadien)tris(trimethylphosphan)cobalt / Structure of Methyl(diazocyclopentadiene)tris(trimethylphosphane)cobalt
Authors: Klein Hans-Friedrich , Ellrich Klaus , Hammerschmitt Birgit , Koch Udo , Cordier Gerhard
Published: March 2015

Co(cyclo-C5H8)(PMe3)3 is oxidized by diazocyclopentadiene to give Co2(N2C5H4)(PMe3)5 (1). Cobalt(I) compounds CoRL′L3 (R = CH3, 4-CH3C6H4, COCH3; L′ = PMe3, CO; L = PMe3; 3 L = CH3C(CH2PMe2)3) or CoRL3 (R = Cl, C6F5; L = PMe3) accommodate diazoalkane ligands to give 18 electron complexes CoR(N2R′)L3 (3: R = CH3, R′ = C5H4, L = PMe3; 5: R = 4-CH3C6H4, R′ = C5H4, L = PMe3; 6: R = CH3, R′ = C(C6H5)2, L = PMe3; 8: R = C6F5, R′= C5H4, L = PMe3; 9: R = C6F5, R′= C13H8, L = PMe3; 11: R = CH3, R′ = C5H4, 3 L = CH3C(CH2PMe2)3; 12: R = CH3, R′ = C13H8, 3 L = CH3C(CH2PMe2)3; 13: R = COCH3, R′ = C13H8, 3 L = CH3C(CH2PMe2)3). Formation of phosphazines Me3PN2R′ (2b: R′ = C5(C6H5)4; 2c: R′ = C5Cl4; 2d: R′ = C13H8) is observed as destructive side-reaction unless it is easily reversed (2 a: R′ = C5H4). 3 crystallizes in the orthorhombic space group P212121 (Nr. 19); a = 1623.0(7), b = 1520.2(6), c = 838.5(3) pm.
Die Kristall- und Molekülstruktur von Lithiumtrifluormethansulfonat Li[SO3CF3] · (THF) / The Crystal and Molecular Structure of Lithiumtrifluoromethanesulphonate Li[SO3CF3] · (THF)
Authors: Schumann H. , Meese-Marktscheffel J. A. , Loebel J.
Published: March 2015

The title compound 1 crystallizes in the monoclinic space group P21/c with a = 1023.4(1), b = 985.4(1), c = 1915.3(4) pm, β = 97.73(1)°, V = 1914.9·10-30 m3 and Z = 8. The X-ray structure was solved from 1977 observed reflections with I > 6σ(I) and refined to a final R value of 0.044. The structure shows Li tetracoordinated by one THF-oxygen and by three oxygen atoms each belonging to a different SO3CF3 group.
Protochelin, ein Catecholat-Siderophor aus einem Bakterium (DMS Nr. 5746) [1] / Protocheline — a Catecholate Siderophore from a Bacterium (DMS No. 5746) [1]
Authors: Taraz K. , Ehlert G. , Geisen K. , Budzikiewicz H. , Korth H. , Pulverer G.
Published: March 2015

The structure elucidation of protocheline (1-N-[2-N′,6-N′-di(2,3-dihydroxybenzoyl)-L-lysyl]-4-N-(2,3-dihydroxybenzoyl)- 1,4-diaminobutane (3 a) isolated from the culture filtrate of a bacterium (DMS No. 5746) grown in an iron-deficient medium is described.
Notizen: OH-Radical-Induced Oxidation of Benzene in the Presence of Oxygen: R·+O2⇆RO2· Equilibria in Aqueous Solution. A Pulse Radiolysis Study
Authors: Pan Xian-Ming , Sonntag Clemens von
Published: March 2015

The reaction of hydroxycyclohexadienyl radical with oxygen was studied by pulse radiolysis. At room temperature the establishment of the equilibria between the hydroxycyclohexadienyl radical (1), oxygen and the hydroxycyclohexadienperoxyl radicals 5-hydroxy-1,3-cyclohexadiene-6-peroxyl radical (3) and 6-hydroxy-1,4-cyclohexadiene-4-peroxyl radical (4), was observed. From the kinetic analysis of the decay of radical 1 at 310 nm overall forward and reverse rate constants of k = 3.1 xl08 dm3 mol-1 s-1 and k = 1.2 x 104 s-1 were obtained. From the analysis of the transient spectra and the products of pulse-irradiated solutions it is concluded that in the equilibrium radical 4 is much favoured over radical 3.
Siliciumverbindungen mit starken intramolekularen sterischen Wechselwirkungen, XLII / Silicon Compounds with Strong Intramolecular Steric Interactions, XLII
Authors: Schäfer Annemarie , Weidenbruch Manfred , Pohl Siegfried , Saak Wolfgang
Published: March 2015

The reactions of alkali metal 2,4,6-tri-tert-butylphenoxides with trichlorosilane and silicon tetrachloride give the bis(2,4,6-tri-tert-butylphenoxy)silanes 3 and 4. Treatment of 3 and 4 with methanol in the presence of ethyldiisopropylamine yields the methoxy derivatives (ArO)2Si(OMe)Cl (5) and (ArO)2Si(OMe)H (6). Tris(2,4,6-triisopropylphenylthio)silane (9) and tris(2,4,6-tri-tert-butylphenylthio)silane (10) are formed by a similar route. The X-ray structure analysis of the extremely crowded compound 10 reveals no significant deviations from the properties of sterically less hindered arylthiosilanes. The planes of the phenyl rings are rotated by ca. 60° against one another resulting in an efficient shielding of the Si- H bond. Efforts to generate silicenium ions from 5, 6, 9, and 10 remained unsuccessful as yet
Untersuchungen an Benzamidinyl-2-phosphazen-Liganden / Investigations on Benzamidinyl-2-phosphazen Ligands
Authors: Roesky Herbert W. , Hasselbring Reinhard , Liebermann Johannes , Noltemeyer Mathias
Published: March 2015

The new ligands (Me3Si)2NC(4-CF3C6H4)NP(Ph)2N(SiMe3) (2) and (Me3Si)2NC(4-Me2NC6H4)NP(Ph)2N(SiMe3) (3) have been prepared from 4-CF3C6H4CN or 4-Me2NC6H4CN, respectively, with LiN(SiMe3)2, Ph2PCl and Me3SiN3. In solution, 2 as well as 3 form two isomers. Their structures (2a, 2 b and 3a, 3b) were tentatively assigned on the basis of NMR investigations. Crystals of 2 a and 3a are triclinic, space group PĪ. Bond lengths and bond angles of 2a and 3a are very similar. The influence of the para-substituents on the bonding properties are found to be negligible
Phase Transition of Na3As under Pressure
Authors: Beister Heinz Jürgen , Syassen Karl , Klein Jürgen
Published: March 2015

We have investigated the high pressure behaviour of Na3As by powder X-ray diffraction. At 3.6 GPa the material undergoes a reversible phase transition from the Na3As structure (P 63/mmc, a = 487.4(8) pm, c = 851.5(20) pm, Z = 2, at 3.6 GPa) to the Li3Bi structure type (Fm 3̅ m, a = 683.5(15) pm, Z = 4, at 3.6 GaP). The equation of states is given for the pressure range up to 26 GPa. Results are discussed with respect to structural properties of related A3
IBV-compounds
4-Substituierte 1,3,5,7-Tetramethyl-1,3,5,7-tetraaza-4λ5-phosphaspiro-[3.3]heptan-2,6-dione; Röntgenstrukturanalyse von 1,3,4,6,7,9,10-Heptamethyl-5-oxa-1,3,7,9,10-pentaaza-4 λ5,6 λ5-diphosphadispiro[3.1.3.1]decan-2,8-dion / 4-Substituted 1,3,5,7-Tetramethyl- 1,3,5,7-tetraaza-4λ5-phosphaspiro[3.3]heptane-2,6-diones; Crystal Structure of 1,3,4,6,7,9,10-Heptamethyl-5-oxa-1,3,7,9,10-pentaaza-4λ5,6λ5-diphosphadispiro[3.1.3.1]decane-2,8-dione
Authors: Breker Johannes , Jones Peter G. , Schmutzler Reinhard
Published: March 2015

The reaction of the tetrachlorophosphoranes RPCl4 (R=Me, Ph) with N,N′-dimethylurea (dmh) (1), or of the diazaphosphetidinone O=C(NMe)2PR (R=CCl3) (3) and chlorine with N,N′-bis(trimethylsilyl)-N,N′-dimethylurea (2) furnished the spiro compounds RP[(NMe)2C=O]2 (7-9). The dichlorophosphoranes O=C(NMe)2PRCl2 (4-6) are intermediates in these reactions; 4 and 6 were isolated but 5 could not be obtained pure. In the reaction of 4 with 2 a mixture of products was formed, from which the novel tricyclic diphosphorane 1,3,4,6,7,9,10-heptamethyl-5-oxa-1,3,7,9,10-pentaaza-4 λ5,6 λ5-diphosphadispiro-[3.1.3.1]decane-2,8-dione (10) was isolated in low yield. Its identity and structure were established by 1H, 13C and 31P NMR spectroscopy and by a single crystal X-ray structure determination, which confirmed the presence of the novel oxazadiphosphetidine ring. 10 crystallizes in C2/c with a = 1321.1(3), b = 687.6(1), c = 1674.5(3) pm, β= 103.30(2)° and Z = 4; R = 0.039 for 1437 unique observed reflections. A crystallographic twofold axis passes through the Me-N···O moiety of the central ring
Darstellung, Reaktionen und spektroskopische Charakterisierung von [Os2X8]2-, X = Cl, Br, I, und Kristallstruktur von (PPN)2[Os2I8] · 2 CH2Cl2 / Preparation, Reactions and Spectroscopic Characterization of [Os2X8]2-, X = Cl, Br, I, and Crystal Structure of (PPN)2[Os2I8] · 2 CH2Cl2
Authors: Preetz W. , Hollmann P. , Thiele G. , Hillebrecht H.
Published: March 2015

The triply bonded octahalogenodiosmate(III) anions [Os2X8]2-, previously known with X = Cl, Br, have now been extended to include the iodide with two staggered OsI4 units. This compound was prepared by treating [Os2Cl8]2- with Nal at room temperature in acetone solution. The structure determination by X-ray diffractometry on single crystals of (PPN)2[Os2I8] · 2 CH2Cl2, reveals crystallization in the monoclinic system, space group P21/c with Z = 4. The Os-Os triple bond is with 2.212(1) Å the longest within the three octahalogenodiosmates(III). The Raman spectra show ν(OsOs) at 285, [Os2Cl8]2-; at 287, [Os2Br8]2- and for the iodo compound at 270.1 cm-1 with up to three overtones. The spectroscopic constants are calculated to be ω1 = 270.9 cm-1; X11 = -0.50 cm-1. The 10 Κ UV-VIS spectra of solid [(n-C4H9)4N]2[Os2X8] exhibit δ-π* transitions with maxima at 723, 690 and 643 nm, superimposed by vibrational fine structures with long progressions of 195, 211 and 183 cm-1 for X = Cl, Br, I, respectively. Oxidation of [Os2X8]2-, X = Cl, Br with the corresponding halogen leads to the cleavage of the Os-Os bond, and the dekahalogenodiosmates(IV), [Os2X10]2-, are formed
New Pyoverdin-Type Siderophores from Pseudomonas fluorescens
Authors: Mohn G. , Taraz K. , Budzikiewicz H.
Published: March 2015

The structures of two new pyoverdins (GM-I and GM-II) isolated from the culture medium of Pseudomonas fluorescens have been elucidated by spectroscopic methods and degradation studies. The pyoverdins consist of a chromophore which could be identified as (1 S)-5-amino-2,3-dihydro-8,9-dihydroxy-1 H-pyrimido[1,2-a]quinoline-1-carboxylic acid substituted at the amino group with a 3-carboxypropanoyl or a succinamoyl residue and at the carboxy group with the N-terminus of D-Ala-D-Lys-Gly-Gly-D-threo-(OH)Asp-D-Glu-D-Ser-L-Ala-D-Ala-D-Ala-L-Ala-L-N5-(OH)Orn.

According to the “short-hand” nomenclature proposed in [2]*** the two compounds should be characterized as pyoverdin-Q-akGGd'qsAaaAO′*-SUCA and pyoverdin-Q-akGGd'qsAaaAO′ *-SUC
Metal Tetrahydroborates and Tetrahydroborato Metalates, 15 [1]. An 11B and 113Cd NMR Study of MBH4–CdCl2 Systems in Dimethylformamide and the X-Ray Structure of CdCl2 · 2 DMF
Authors: Linti Gerald , Nöth Heinrich , Thomann Martina
Published: March 2015

CdCl2 dissociates in dimethylformamide into the species Cd(DMF)6
2+, CdCl(DMF)5
+ and CdCl3
- as determined by 113Cd NMR spectroscopy. 11B and 113Cd NMR spectra of MBH4/CdCl2 solutions in this solvent show the presence of complexes [CdCl2
-n(BH4)n+1]- with rapid exchange of BH4
- and Cl- at ambient temperature. There is no evidence that Cd(BH4)2 is formed in a metathetical reaction.

The crystal structure of CdCl2 · 2 DMF has been determined. It is a coordination polymer containing hexacoordinated Cd atoms with the DMF molecules in cis-position. Coordination of DMF occurs via the carbonyl oxygen atoms.
Die Reaktion von 1,1,3,3-Tetrakis(dimethylamino)-1 λ5,3 λ5-diphosphet mit Nitrilen / The Reaction of 1,1,3,3-Tetrakis(dimethylamino)-1 λ5,3 λ5-diphosphete with Nitriles
Authors: Plass Winfried , Heckmann Gernot , Fluck Ekkehard , Krüger Carl , Werner Stefan
Published: March 2015

Reaction of 1,1,3,3-tetrakis(dimethylamino)-lλ5,3λ5-diphosphete (1) with perfluorobenzonitrile yields 1,1,3,3-tetrakis(dimethylamino)-4-(4-cyano-2,3,5,6-tetrafluorophenyl)-1 -fluoro-1λ5,3λ5-diphosphabuta-1,3-diene (3); reaction of 1 with benzoisonitrile gives 2,2,4,4-tetrakis(dimethylamino)-1-isocyano-1-phenyl-2λ5,4λ5-diphosphapenta-1,3-diene (4). The new products 3 and 4 are characterized by their NMR, mass, and IR spectra. The mechanism of formation is discussed. The structure of 3 was elucidated by an X-ray structural analysis.
The Isomorphous Structures of Ammonium trans-Diiodobis(ethanedial-dioximato-(1–)-N,N′)cobaltate(III) and Ammonium trans-Diiodobis(ethanedial-dioximato-(1–)-N,N′)rhodate(III): Extended Metaloximate Chains with a Novel ···I–M–I···I–M–I··· Zigzagged Structure
Authors: Mégnamisi-Bélombé Michel , Nuber Bernhard
Published: March 2015

The ammonium salts of the complex anions trans-diiodobis(ethanedial-dioximato)-cobaltate(III), [Col2(GH)2]-, and trans-diiodobis(ethanedial-dioximato)rhodate(III), [RhI2(GH)2]- (GH- = ethanedial dioximate or glyoximate), have been synthesized and their structures determined from single crystal X-ray diffraction data at room temperature. The crystals of the two salts are monoclinic, space group C2/c. NH4[CoI2(GH)2] (I) crystallizes as dark-brown prisms with a greenish reflectance; its crystal data are: C4H10Col2N5O4, Mr = 504.90; a = 8.910(6), b = 11.700(9), c = 11.691(6) Å; β = 93.55(5)°; V = 1216.4 Å3; Z = 4; Dc = 2.78 Mg m-3. NH4[RhI2(GH)2] (II) crystallizes as yellow-brown blocks with crystal data: C4H10I2N5O4Rh, Mr = 548.88; a = 9.038(4), b = 11.949(5), c = 11.770(3) Å; β = 95.54(3)°; V = 1265.16 A3; Z = 4; Dc = 2.87 Mg m-3. The two structures were refined to a final RW = 0.045 for 1209 observed independent reflections and 95 parameters for I, and to a final RW = 0.040 for 1922 observed independent reflections and 87 parameters for II. The coordination geometry around Co or Rh in the anionic complexes is a distorted (4 + 2) octahedron of four equatorial chelating N atoms and two apical iodides. The H atoms of the hydroxyl groups are involved, as usual, in intramolecular O—H—O bridges with uniform Ο···Ο separations of 2.582 Å for I, and 2.713 Å for II. The rectilinear I—Co—I or I—Rh—I triads form “infinite” zigzag chains extending parallel to the ab plane, with a weak I—I contact of 3.988 Å for I, and 4.010 Å for II.
Beiträge zur Chemie des Phosphors, 209 / Contributions to the Chemistry of Phosphorus, 209
Authors: Baudler Marianne , Koll Bernhard , Arndt Volker
Published: March 2015

a-P9Et5 (1) and a-P9(i-Pr)5 (2) have been obtained by reacting a mixture of (PEt)5 and PC13 and of i-PrPCl2 and P4, respectively, with magnesium. Compound 1 has been isolated in 95% purity, whereas 2 has been highly enriched in the product mixture. According to their 31P{1H}-NMR spectra, 1 and 2 are 2,4,6,8,9-pentaorganyltricyclo[3.3.1.03.7]nonaphosphanes (a-P9R5) containing a P9 skeleton analogous to that of noradamantane. In addition, small portions of another constitutional isomer with a structure analogous to that of brexane (b-P9R5) have been detected.
Notizen: Synthesis and Structure of an 1,3-Dibora-2,5-disilacyclohexane Derivative
Authors: Wong-Chi-Man Wong-Wee-Choy , Pritzkow Hans , Siebert Walter
Published: March 2015

Hydroboration, 3,3-Dimethyl-(e)-1-chlorodimethylsilyl-1-chloro-dimethylaminoboryl-butene-1,1,3-Bis(dimethylamino-2,2,5,5-tetramethyl-4,6-bis-(t-butylethylene)-1,3-dibora-2,5-disilacyclohexane

Hydroboration of chlorodimethyl(3.3-dimethylbutynyl)silane with HBCl2/BCl3 yields 3.3-dimethyl-(e)-1-chlorodimethylsilyl-1-dichloroboryl)-butene-1 (1 a), in which a chlorine atom at the boron can be substituted using Me3SiNMe, to give the corresponding chlorodimethylaminoboryl derivative 1 b. Dehalogenation of 1 b with Na/K alloy does not lead to the three-membered ring compound 2, but surprisingly yields the 1,3-dibora-disilacyclohexane derivative 3. The X-ray structure analysis shows a six-membered ring with a chair conformation, a small angle B 1–Si 2–B 1′ = 95.4(1)°, and long Si–B bonds (2.038 Å).
Tris(tert-butoxo)silylthiolato-Komplexe des Vanadiums(V, IV, III) / Tris(tert-butoxo)silylthiolato Complexes of Vanadium(V, IV, III)
Authors: Preuss Fritz , Steidel Martina , Exner Reiner
Published: March 2015

The complexes ′C4H9N = V(O′C4H9)3-n[SSi(O′C4H9)3]n, O = V(O′C4H9)3-n[SSi(O′C4H9)3]n, O=V[SSi(O′C4H9)3]2 (9) and VCl[SSi(O′C4H9)3]2 have been prepared by reaction of chlorovanadium compounds with LiSSi(O′C4H9)3. All complexes are characterized by NMR (1H, 51V) and ESR spectroscopy. 9 has been found by X-ray diffraction analysis to be a distorted trigonal bipyramidal complex with bidentate thiolate ligands.
Die unterschiedliche Reaktivität von 1,4-Disilabutan und n-Tetrasilan gegenüber sekundären Aminen / Differences in Reactivity of 1,4-Disilabutane and n-Tetrasilane towards Secondary Amines
Authors: Schmidbaur Hubert , Schuh Heinz
Published: March 2015

1,4-Disilabutane H3SiCH2CH2SiH3 (1) and n-tetrasilane H3SiSiH,SiH2SiH3 were employed as model systems for the preparation of silicon-rich aminosilanes potentially useful for the deposition of silicon nitride Si3N4. 1 reacts with the appropriate equivalents of diethylamine in an alkane solvent and in the presence of the two-phase catalyst NaNH2/18-crown-6 to give the products (Et,N)2SiHCH2CH2SiH3, (Et2N)2SiHCH2CH2SiH2(NEt2), and (Et2N)2SiHCH2CH2SiH(NEt2)2. By contrast, n-Si4H10 undergoes a cleavage reaction under similar conditions to yield H3SiNEt2 and H2Si(NEt2)2 together with a mixture of polysilanes SinH2n+2, the composition of which is depending on the reaction conditions and the nature of the catalyst (NaH and NaNH2). Diethylaminopolysilanes are also formed, but only in trace quantities. Treatment of n-Si4H10 with pyrrole (C4H5N) leads to the formation of trisilane accompanied by the pyrrolylsilanes H2Si(C4H4N)2, HSi(C4H4N)3, and Si(C4H4N)4. The differences in reactivity suggest excellent leaving group properties of silyl anions in the reaction with amines.
Zum Cycloadditionsverhalten von 5-Azido-4-trifluormethyl-1,3-azolen / Cycloaddition Reactions with 5-Azido-4-trifluoromethyl-1,3-azoles
Authors: Burger Klaus , Höß Eva , Sewald Norbert , Geith Klaus , Riede Jürgen , Bissinger Peter
Published: March 2015

[3+2] Cycloaddition reactions of 5-azido-4-trifluoromethyl-1,3-azoles with various CC multiple bond systems are described. On reaction of 5-azido-4-trifluoromethylthiazoles 2 with 2,3-dimethylbuta-1,3-diene no [3+2] cycloaddition products could be isolated, 5,6-dihydro-2 H-pyrane 19 was formed exclusively. Photolysis of 1,2,3-triazoles 23, 24, obtained from 2 and electron deficient alkynes, yields imidazo[5,1-b]thiazoles 28. This photoreaction can be interpreted mechanistically as a “Thio-Cornforth-Reaction”.
Darstellung und spektroskopische Charakterisierung von Cyansulfoniumsalzen. S(CN)3
+AsF6- und (CH3)2SCN+MF6- (M = As, Sb) [1] / Preparation and Spectroscopic Characterization of Cyansulfonium Salts. S(CN)3+AsF6- and (CH3)2SCN+MF6- (M = As, Sb) [1]
Authors: Minkwitz Rolf , Gerhard Volker
Published: March 2015

Tricyansulfonium hexafluoroarsenate S(CN)3
+AsF6
- is prepared by halide-pseudohalide exchange with SBr3
+AsF6
- and AgCN. The cyandimethylsulfonium salts (CH3)2SCN+AsF6
- and SbF6
- are obtained via reactions of CH3SCN with CH3OSO+MF6
- (M = As, Sb) in liquid SO2. The compounds are characterized by Raman, IR and NMR spectroscopy.
(Acetoxymethyl)methylphenylgerman: Synthese, thermisches Verhalten und olfaktorische Eigenschaften / (Acetoxymethyl)methylphenylgermane: Synthesis, Thermal Behaviour and Olfactoric Properties
Authors: Tacke Reinhold , Wiesenberger Frank
Published: March 2015

(Acetoxymethyl)methylphenylgermane [PhMeGe(H)CH2OAc, lc] was synthesized by a five-step synthesis starting from trichloro(chloromethyl)germane [Cl3GeCH2Cl → PhCl2GeCH2Cl → PhMeGe(Cl)CH2Cl → PhMeGe(OAc)CH2OAc → PhMeGe(H)CH2OH → PhMeGe(H)CH2OAc]. The germane le and its carbon analogue PhMeC(H)CH2OAc (la) are thermally stable (solutions in C6D6; 160 °C, 48 h), whereas the structurally analogous silane PhMeSi(H)CH2OAc (lb) undergoes a rearrangement upon heating (formation of the silane PhMe2SiOAc; half-life in C6D6 at 135 °C: 7.7 h). By analogy to the perfume la (hydratropyl acetate) and its silicon analogue lb (sila-hydratropyl acetate), the germane lc (germa-hydra-tropyl acetate) exhibits a sweet-floral odor. Despite of some differences, the olfactoric properties of the C/Si/Ge-analogues la/lb/lc are mainly characterized by analogies.
Die Struktur von [Si(bzac)3]+[HCl2]- (bzac = 1-phenyl-1,3-butandionato) / The Structure of [Si(bzac)3]+[HCl2]- (bzac = 1-phenyl-1,3-butanedionato)
Authors: Thewalt Ulf , Link Ulrich
Published: March 2015

The title compound which was prepared by Dilthey already in 1903 has been investigated by X-ray crystallography. The complex cation has the expected octahedral tris-chelate structure with the ligands in a meridional arrangement. The complex crystallizes as a racemate. The Cl · · · Cl distance in the [HCl2]- anion is 3.145(4) A.
Synthese und Röntgenstrukturanalyse einer acyclischen Schwefel-Stickstoff-Verbindung mit einer S5N4-Kette / Synthesis and X-Ray Structural Analysis of an Acyclic Sulfur Nitrogen Compound with an S4N5 Chain
Authors: Wolmershäuser G. , Mann P. R.
Published: March 2015

The title compound was obtained on reduction of R2S4N3
+Cl- via dismutation. Its crystal structure was determined by X-ray diffraction.

(CH3-C6H4)2-S5N4: The conformation of the SN chain closely resembles that of (SN)x; however, the bond-distances are in accordance with the assumption of alternating S(II) and S(IV) atoms.
Stereoselective Reaction Mass Spectrometry with Cyclic α-Amino Acids
Authors: Martens Jürgen , Lübben Stefan , Schwarting Walter
Published: March 2015

Stereoselective reaction mass spectrometry in the chemical ionization (isobutane) mode has been used to detect the absolute configuration of enantiomerically pure cyclic α-amino acids. Thus, an enantiomerically pure cyclic α-amino acid was allowed to react on a micromole level with both enantiomers of a chiral selector and the mass spectra were detected. The relative abundances of characteristic ions formed by the diastereoselective reaction between the α-amino acid and the chiral selector of the same configuration were much higher than those ions formed by the α-amino acid and the chiral selector of a different configuration. The absolute configuration of the α-amino acid may be predicted by careful examination of the two stereoselective reaction mass spectra of the α-amino acid measured with both, the chiral (R)-and (S)-selector respectively. Various (R)- and (S)-carboxylic acids and (R)- and (S)-α-phenylethyl amine have been used as chiral selectors.
Notizen: Mischkristallbildung und Natriumionenleitung im System Na3PO4/Na2CO3 / Solid State Miscibility and Sodium Ion Conduction in the System Na3PO4/Na2CO3
Authors: Lissel Eckhard , Jansen Martin
Published: March 2015

Na3PO4 and Na2CO3 form solid solutions with the high-temperature Na3PO4 structure and a maximum content of nearly 25 mole-% Na2CO3 at 873 K and 15 mole-% at room temperature. The sodium ion conduction is enhanced due to the creation of sodium vacancies. In contrast to pure Na3PO4 there is a second order transition into the highly ionic conducting state. As a result of rotational disorder of the anions the activation energy is lowered.
Notizen: Electroreduction of Organic Compounds, XVIII / Electrochemical Dehalogenation of Chlorinated Dibenzofurans and Dibenzo-p-dioxins in Methanol
Authors: Voss J. , Altrogge M. , Wilkes H. , Francke W.
Published: March 2015

Mono and polyhalogenated dibenzofurans and dibenzo-p-dioxins are electrochemically reduced in a divided cell in technical methanol at a lead cathode.
Dimere und polymere Kupfer(I)-Komplexe von Dithiocarbaminsäureestern. Strukturen von [CuI(L1)2]2 und [CuCl(L2)2]2, [CuCl(L1)]n und [CuI(L2)]„ (L1 = N-Methyl-S-methyldithiocarbaminsäureester, L2 = N-Phenyl-S-methyldithiocarbaminsäureester) / Dimeric and Polymeric Copper(I) Complexes of Dithiocarbamate Esters. X-Ray Structures of [CuI(L1)2]2 and [CuCl(L2)2]2, [CuCl(L1)]n and [CuI(L2)]n (L1 = N-Methyl-S-methyldithiocarbamate, L2 = N-Phenyl-S-methyldithiocarbamate)
Authors: Mattes Rainer , Schulbert Klaus
Published: March 2015

Reactions of N-methyl-S-methyldithiocarbamate (L1) and N-phenyl-S-methyldithiocarbamate (L2) with Cu(I) or Cu(II) halides yield the 2:1 and 1 : 1 complexes [Cul(L1)2]2 (1), [CuCl(L2)2]2 (2), [CuCl(L1)]n (3) and [CuI(L2)]n (4). Their structures have been determined by single crystal X-ray crystallography. 1 and 2 are dimeric. Cu(I) is tetrahedrally coordinated. The CuS2Cu cores are planar with short (in 1 and 2: —228 pm) and long (1: 276.6(2); 2: 256.4(1) pm) Cu—S distances. 3 and 4 are polymeric with edge linked tetrahedral coordination polyhedra CuS2CuX2Cu. The Cu ⋯ Cu distances in 3 are 279.6(1) and 288.0(1) pm across the sulfur and the halogen bridged edges, respectively. In 4, with iodide bridges, these distances are 297.7(6) and 264.8(7) pm, respectively. The differences are caused by sterical interactions of the donor atoms within the coordination spheres.
Die Wechselwirkung von N3F mit Lewis-Säuren und HF. N3F als möglicher Vorläufer für die Synthese von N3
+-Salzen / The Interaction of N3F with Lewis-Acids and HF. N3F as Possible Precursor for the Synthesis of N3
+ Salts
Authors: Schatte Gabriele , Willner Helge
Published: March 2015

Triazadienyl fluoride, N3F, forms stable adducts with BF3 and AsF5 at low temperatures, as demonstrated by infrared measurements. The Lewis acids are bonded to the Nα-atom of N3F, as deduced from the data for 15N-isotopically enriched N3F. The basicity of N3F is comparable to that of ethine and ethene, according to the HF stretching frequency of the N3F/HF complex isolated in an argon matrix. Despite the low NF bond energy (< 150 kJ/mol), abstraction of the fluoride ion and formation of an N3
+ salt was not possible.

The different behavior of N3F and ClN3 towards Lewis acids is discussed.
Halfsandwich cyclo-Pentasulfido and cyclo-Pentaselenido Complexes, (η5-C5Me5)M(NO)(E5) (E = S, Se; M = Cr, Mo, W)
Authors: Herberhold Max , Jin Guo-Xin , Kremnitz Walter , Rheingold Arnold L. , Haggerty Brian S.
Published: March 2015

The reactions of the pentamethylcyclopentadienyl halfsandwich nitrosyl complexes Cp*Cr(NO)2I and Cp*M(NO)I2 (M = Mo, W) with either methanolic ammonium polysulfide solutions or hydrogen selenide solutions (generated by hydrolysis of Al2Se3) can be used to prepare cyc/o-pentachalcogenido compounds such as Cp*M(NO)(S5) (M = Cr (la), Mo (2a), W (3a)) and Cp*M(NO)(Se5) (M = Cr (lb), W (3b)). The chromium complex Cp*Cr(NO)(S5) (la) is also formed in high yield by photodecarbonylation of Cp*Cr(CO)2NO in acetonitrile solution in the presence of excess sulfur. An X-ray structure analysis of Cp*W(NO)(S5) (3 a) revealed a cyclo-S5 chelate ligand in the chair conformation and an almost linear nitrosyl group.
Die Reaktionen von Wolframhexachlorid mit überschüssigem 2,2-Dimethylpropylidinphosphan; die Kristallstrukturen von WCl5P2(C5H9)3, WCl4P5(C5H9)5 und [C3(C4H9)3]+[WCl5(C4H9C≡CC4H9)]- / The Reactions of Tungsten Hexachloride with Excess 2,2-Dimethylpropylidynephosphane; the Crystal Structures of WCl5P2(C5H9)3, WCl4P5(C5H9)5, and [C3(C4H9)3]+[WCl5(C4H9C=CC4H9)]⁻
Authors: Weller Frank , Pauls Irene , Dehnicke Kurt , Becker Gerd
Published: March 2015

The reaction of tungsten hexachloride with excess 2,2-dimethylpropylidynephosphane, C4H9—C≡P, leads to the tungsten phosphaalkyne clusters WCl5P2(C5H9)3 and WCl4P5(C5H9)5, as well as to the tris(t-butyl)cyclopropenium pentachloro tungsten alkyne complex [C3(C4H9)3]+[WCl5(C4H9C≡CC4H9)]-. All complexes were characterized by X-ray structure determinations.

WCl5P2(C5H9)3: Space group P2,/n, Z = 8,4653 observed unique reflexions, R = 0.033. Lattice dimensions at 20 °C: a = 1577.8(2), b = 1661.3(1), c = 1869.8(2) pm, β = 110.64(1)°. The compound has a molecular structure, in which the tungsten atom is surrounded by three chlorine atoms, three carbon atoms with W—C distances of 182, 230, and 231 pm, and by one phosphorus atom with W—P = 246 pm.

WCl4P5(C5H9)5: Space group P21/c, Z = 4, 3517 observed unique reflexions, R = 0.043. Lattice dimensions at 20 °C: a = 1770.0(2), b = 1032.9(2), c = 1876.0(3) pm, β = 102.86(1)°. The complex has a molecular structure, in which the tungsten atom is surrounded by two chlorine atoms, two carbon atoms with W—C distances of 189 and 215 pm, as well as by four phosphorus atoms with W — P distances of 242, 250, 264, and 268 pm.

[C3(C4H9)3]+[WCl5(C4H9C=CC4H9)] : Space group P21/c, Ζ = 4, 3284 observed unique reflexions, R = 0.052. Lattice dimensions at 20 °C: a = 941.5(3), b = 1762.2(6), c = 1903.5(7) pm, β = 92.27(3)°. The compound consists of tris(t-butyl)cyclopropenium ions, and anions [WCl5(C4H9C=CC4H9)]⁻, in which the bis(t-butyl)alkyne ligand is coordinated side-on, corresponding to a cyclopropene type structure with W—C distances of 198 pm.
Notizen: Synthesis of 5-Methoxycarbonyl-11-methylfuro(2,3-c)acridan-6(11H)ones
Authors: Jayabalan L. , Shanmugam P.
Published: March 2015

A convenient photochemical route to 11-methylfuro(2,3-c)acridan-6(11 H)ones is reported.
[K(222-crypt)]2TeSe10 und [Ba(222-crypt)(en)]TeSe10·en0,5: Verbindungen mit einem neuen spirozyklischen TeSe10
2--Polychalkogenid-Anion / [K(222-crypt)]2TeSe10 and [Ba(222-crypt)(en)]TeSe10 · en0.5: Compounds with a New Spirocyclic Polychalcogenide Anion TeSe10
2-
Authors: Zagler Roland , Eisenmann Brigitte
Published: March 2015

Attempts to prepare selenotellurates with coordination numbers greater than three for the tellurium atom led to the title compounds [K(222-crypt)]2TeSe10 and [Ba(222-crypt)(en)]TeSe10·en0.5 with a new mixed polychalcogenide anion TeSe10
2-. The crystal structures of both compounds contain four-coordinate tellurium with two bidentate Se5 forming a spirocyclic arrangement with Te as the common spiro atom in a planar, almost square coordination. The potassium cation is cryptated by the macro-bicyclic aminopolyether 222-crypt (CN 8), whereas the barium cation is coordinated by the cryptand and a further solvate molecule of ethylenediamine, resulting in a total coordination number of 10. [K(222-crypt)]2TeSe10: PI, a = 1333.3(6) pm, b = 1214.6(6) pm, c = 1078.3(4) pm, α = 95.80(6)°, β = 90.18(6)°, γ = 115.20(6)°, R = 0.073; [Ba(222-crypt)(en)]TeSe10 · en0.5: PĪ, a = 1802.2(6) pm, b = 1132.1(4) pm, c = 1049.4(4) pm, α = 79.80(6)°, β = 87.27(6)°, γ = 84.63(6)°, R = 0.076.
Bis- und Tris(aluminium)alkan-Verbindungen, II: 1,1- und 1,2-Bis(chloro/ethylaluminium)ethan / Bis- and Tris(aluminum)alkane Compounds, II: 1,1- and 1,2-Bis(chloro/ethylaluminum)ethanes
Authors: Martin Heinz , Bretinger Helmut
Published: March 2015

The syntheses of bis(aluminum)ethane compounds – bis(dichloroaluminum)ethanes to chlorine free bis(diethylaluminum)ethanes 1-10 are described. The connecting ethylene between the two aluminum atoms is identified either as C2H4 (1,2–) or as CH(CH3) (1,1–). The syntheses of Cl2AlEt, ethylaluminumsesquichloride and Et2AlCl from aluminum, ethylene and AlCl3 or EtAlCl2 via bis(aluminum)ethane compounds under various conditions are presented.
Synthesis and X-Ray Crystal Structure of the Double Salt, Bis(tetramethylammonium) Triiodide trans-Diiodobis(ethanedial dioximato(1 –)-N,N′)cobaltate(III). (N(CH3)4)2I3(CoI2(GH)2)
Authors: Mégnamisi-Bélombé Michel , Nuber Bernhard
Published: March 2015

A “one-pot” reaction involving cobalt(II) nitrate hexahydrate, iodine, tetramethylammonium iodide and ethanedial dioxime (or glyoxime, GH2) in water/methanol solution has afforded the novel double salt, bis(tetramethylammonium) triiodide trans-diiodobis(ethanedial dioximato)cobaltate(III), (N(CH3)4)2I3(CoI2(GH)2). The structure of the salt was determined from single crystal X-ray diffraction data. Crystal data: orthorhombic space group Pnma; C12H30CoI5N6O4, Mr = 1015.84; a = 10.60(1), b = 12.531(5), c = 21.47(2) Å; V = 2851.83 Å3; Z = 4; Dc = 2.36 Mg m-3. The structure consists of three distinctive molecular species, namely, (N(CH3)4)+, I3
-, and (CoI2(GH)2)-. The cobaloximatic anion contains CoIII in the usual (4+2) octahedral ligand field of four chelating N atoms lying within the molecular equatorial plane, and two iodides occupying the apical positions. The atomic triads, I -Co-I and I- I - I, are slightly bent by an angle of 177.3° and 176.8°, respectively. Two symmetrical O-H-O bridges with slightly diverging O · · · O separations (2.492 and 2.516 A) are effective within the cobaloximatic anion. Van der Waals type intermolecular interactions occur only between the I atoms of adjacent I3
- and ICol units. These interactions give rise to the formation of “stripes” that propagate throughout the structure, parallel to the crystallographic ac plane. There are no interactions amongst ICol triads in this material.
PhAs(C5H4)2TiCl2: Das erste Arsen-überbrückte Titanocenophan / PhAs(C5H4)2TiCl2: The First Arsenic-Bridged Titanocenophane
Authors: Klouras Nikolaos
Published: March 2015

By reacting PhAsCl2 with NaC5H5 in toluene under low temperature conditions PhAs(h1-C5H5)2 was obtained. Metallation of PhAs(h1-C5H5)2 with n-BuLi followed by reaction with TiCl4 led to the As-bridged [1]titanocenophane. The structure and conformation of this air-stable compound are discussed in the light of its 1H NMR spectrum.
Verteilung und Valenz der Kationen in Spinellsystemen mit Eisen und Chrom, II. Zur Stöchiometrie des Spinells FeCr2O4 / Distribution and Valence of the Cations in Spinel Systems with Iron and Chromium, II. On the Stoichiometry of the Spinel FeCr2O4
Authors: Eggert Andreas , Riedel Erwin
Published: March 2015

FeCr2O4 has been prepared under CO-CO2-atmosphere with oxygen partial pressures between 10-18 and 10-8 bar. X-Ray and Mößbauer investigations show that under higher pressures FeCr2O4 is not stoichiometric but contains Fe(III), and that corund type Cr2O3 as an additional phase has been formed. In the wide pressure range from 10-17 to 10-14 bar the contents of Fe(III) are lower than 1% of total iron, and the corund phase is negligible.
Synthesis and Characterization of a New Technetium(V) Complex with Butane-2,3-dionemonoxime and Some PPP Calculations
Authors: Hassan Mostafa K. , El-Shahawy Anwar S. , Mahfouz Refaat M. , Osman Ahmed H. , Mahfouz Refeat M.
Published: March 2015

Using a PPP(SCF)—CI calculation, the structure of the butane-2,3-dionemonoxime ligand has been determined. Via SCF—MO calculations, the ionization potential, the electron affinity, the charge densities in the three states (a molecule, a cation and an anion), the SCF-HO-MO’s and the SCF-LUMO’s were calculated in addition to the molecular dipole moment. A new technetium(V) oxocomplex with butane-2,3-dionemonoxime ligand CH3COCNOHCH3 (diacetylmonoxime) has been synthesized and characterized. The complex formation was performed in an alkaline mixture of water and ethanol by reduction of pertechnetate with NaBH4 in the presence of the monoxime ligand. Infrared, UV-visible spectra, electrophoresis and HPLC data of the resulting complex are reported and discussed.
Spectroscopic Characterization of trans-Fe(CO)3L2 Complexes (L = Phosphine or Phosphite)
Authors: Inoue Hidenari , Takei Tomoko , Heckmann Gernot , Fluck Ekkehard
Published: March 2015

A series of disubstituted trans-Fe(CO)3L2 complexes (L = phosphine or phosphite) have been characterized by infrared, 57Fe Mössbauer, and 31P NMR spectroscopy. The triple-bond nature of the carbonyl ligands of trans-Fe(CO)3L2 is strengthened with increasing ironto-phosphorus π back-donation. A linear correlation between the isomer shifts and the quadrupole splittings has demonstrated that the phosphorus-to-iron σ donation is offset by the iron-to-phosphorus π back-donation. The linear dependence of the coordination shifts on the isomer shifts has revealed that the iron-to-phosphorus π back-donation plays an important role in the Fe– P bond. There exists a strong interaction between trans phosphorus ligands through the dπ orbitals associated with the P–Fe–P bond.
Preparation, Spectral and Structural Characterization of Two Polymeric 1:1 Mixed Ligand Complexes of Copper(II) Azide with 4-Methylquinoline and 2-Methylpyridine
Authors: Goher Mohamed A. S. , Mautner Franz A.
Published: March 2015

Two 1:1 mixed ligand complexes of copper(II) azide with substituted quinoline and pyridine, namely catena di-μ(1,1)-azido-(4-methylquinoline)copper(II) (1) and catena di-μ(1,3)-azido-[di-μ(1,1)-azido-bis(2-methylpyridine)dicopper(II)] (2) have been prepared and characterized by X-ray crystallography.

Crystal data: 1, C10H9N7Cu, space group P21/c, a = 577.8(2), b = 2202.3(5), c = 919.9(2) pm, β = 93.92(2)°, Ζ = 4, and R = 0.035 for 1293 observed MoKa data; 2, C6H7N7Cu, space group P21/a, a = 823.7(2), b = 1303.8(4), c = 895.3(3) pm, β = 112.23(2)°, Ζ = 4, and R = 0.022 for 2133 observed ΜοΚα diffractometer data. In the structure of 1, the Cu(II) has a strongly distorted trigonal bypyramidal coordination, where both azido groups function as μ(1,1) bridging ligands resulting in a columnar structure along the a axis. The polymeric complex 2 has a less distorted square pyramidal structure; one half of the azide groups act as μ(1,1) bridging ligands to form centrosymmetric dimers. These dimeric units are further connected by the remaining μ(1,3) bridging azido groups to form layers within the ab-plane. Infrared and electronic spectral data are also presented and discussed.
Notizen: Darstellung und Kristallstruktur der Verbindung LiCo6P4 / Synthesis and Crystal Structure of the Compound LiCo6P4
Authors: Buschmann Rolf , Schuster Hans-Uwe
Published: March 2015

A new compound LiCo6P4 could be synthesized, it crystallizes in the hexagonal space group P6̅m2 with the lattice constants a = 658.4(3) pm, c = 333.8(2) pm, c/a = 0.507. The structure shows close relations to the Fe2P- or Zr2Fe12P7-type structures.
Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen, LXXXIX / Multiple Bonds between Main Group Elements and Transition Metals, LXXXIX
Authors: Herrmann Wolfgang A. , Marz Dieter W. , Herdtweck Eberhardt
Published: March 2015

Reaction of (N-trimethylsilyl)-α-aminopicolin with the rhenium(V) oxohalogenide (η5-C5Me5)ReOCl2 (Me = CH3) exemplifies a simple, clean synthesis of imido-metallosiloxanes, compounds of the structure R3SiO—M=N—R′. The compound (η5-C5Me5)ReCl[OSi(CH3)3](NCH2-2-C5H4N) thus formed under HCl elimination has a square-pyramidal molecular structure (single crystal X-ray diffraction).
Metallkomplexe in Anorganischen Matrices, 5 [1] / Metal Complexes in Inorganic Matrices, 5 [1]
Authors: Egger Christian , Schubert Ulrich
Published: March 2015

A heterogenized rhodium complex, prepared by sol-gel processing of Rh(CO)Cl[PPh2CH2CH2Si(OEt)3]2 and Si(OEt)4, is shown to catalyze the conversion of the silanes H4-nSiPh„ (n = 1 - 3) or (HMe2Si)2O to (poly)siloxanes by air or water. Using THF as a solvent, the silanoles Ph3SiOH or Ph2Si(OH)2 are obtained instead. The reaction of phenylacetic acid or acetic acid with HSiPh3 to give silyl esters is catalyzed by the same compound.
Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXVIII [1,2] / Studies on the Chemistry of Isoindoles and Isoindolenines, XXXVIII [1,2]
Authors: Kreher Richard P. , Hennige Hans , Konrad Michael , Uhrig Jürgen , Clemens Andrea
Published: March 2015

3-Alkoxy-1 H-isoindoles bearing substituents at the five-membered ring have been synthesized starting with substituted isoindoline-1-ones via regiospecific O-alkylation with trialkyl oxonium tetrafluoroborates or alkyl trifluoromethanesulfonates and subsequent NH-deprotonation. The dependence of spectroscopic properties on the substituents has been investigated. The heterocyclic imidates exist exclusively in the benzenoid 1H-structure; the tautomeric o-quinonoid 2 H-form cannot be detected by spectroscopic means.
HPTLC-Analyse von Ginsenosiden zur Bewertung von Ginseng-Extraktionen mit Methanol-Wasser, Wasser oder Ammoniak / HPTLC Analyses of Ginsenosides for the Evaluation of Ginseng Extractions with Methanol-Water, Water or Ammonia
Authors: Schilke Oliver , Hohaus Eberhard , Lentz Harro , Kim Jeong R.
Published: March 2015

Korean Ginseng roots were extracted with methanol-water, water and liquid and supercritical ammonia. The yields of the extracts by different methods are reported. The extracts were analyzed by high-performance thin-layer chromatography. Retention value factors of ginsenosides are tabellized. The absolute yields have been measured in mg ginsenoside per g ginseng root for the used standard ginsenosides. Formally the ammonia extraction at 334 K and 26 bar is found to be favourable. The supercritical condition of 418 K and 130 bar leads to a decomposition of the ginsenosides. Possibilities of fractionation by different solvents or different temperatures are indicated, but attempts are still required to get fractions of several extraction agents.
Eine neue 1,4-Diboracyclohexa-2,5-dien-Synthese / A New Synthesis of 1,4-Diboracyclohexa-2,5-diene
Authors: Thomas M. , Pritzkow H. , Siebert W.
Published: March 2015

Borontrichloride reacts with two equivalents of z-3-diethylboryl-4-triethylstannylhex-3-en (2) to give the intermediate 3. In situ ethylation of 3 yields the bis(z-3-diethylborylhex-3-en-4-yl)ethylboran (4). Reactions of 4 with cyclopentadienylcobaltbis(ethen) or molybdenumhexacarbonyl lead to the mononuclear complexes 5 and 6. Their constitution is derived from NMR and MS data, and confirmed for 6 by an X-ray structure analysis.
Synthese neuer Phosphan- und Fluorophosphankomplexe durch Ligandmodifikation in der Koordinationssphäre von kationischen Cyclopentadienyleisen-bis(phosphan)-Komplexen / Synthesis of New Phosphane and Fluorophosphane Complexes by Ligand Modification in the Coordination Sphere of Cationic Cyclopentadienyliron Bis(phosphane) Complexes
Authors: Schumann Hans , Eguren Liliana
Published: March 2015

The reaction of nitrile solvate complexes [(C5H5)(P(OCH3)3)2(NCCH3)Fe]PF6 (Ia) and [(C5H5)(DPPE)(NCCH3)Fe]PF6 (Ib, DPPE = [(C6H5)2PCH2]2) with halogenophosphanes, -arsines or -stibines L′ afford the cationic complexes [(C5H5)(L2)(L′)Fe]PF6 (II, L2 = (P(OCH3)3)2, L′ = PCl3, P(CH3)Cl2, P(t-C4H9)Cl2, P(C6H5)Cl2, P(C6H5)2Cl, PBr3, AsCl3, SbCl3; III, L2 = DPPE, L′ = PCl3, AsCl3, SbCl3) in high yield. Spectroscopic data are given together with the characterization of [(C5H5)(P(OCH3)3)2(P(t-C4H9)Cl2)Fe]PF6 (IIc) by single crystals X-ray diffraction analysis. Through reduction of coordinated P– Cl ligands in selected complexes II and III complexes bearing PH3, P(C6H5)H2 and P(C6H5)2H ligands are available. With anhydrous KF in acetonitrile solution in the presence of dibenzo-18-crown-6, the coordinated P– Cl ligands in selected complexes II and HIII undergo Cl/F-exchange with formation of related complexes with P(CH3)ClF, P(CH3)F2, PF2Cl and PF3 ligands.
Synthese, Struktur und Eigenschaften der Hexabromotellur(IV)- und Tridekabromotritellur(IV)säure-Hydrate. Kristallstrukturen der Oxonium-Salze [H9O4]2[TeBr6] und [H9O4][Te3Br13] / Synthesis, Structure and Properties of Hexabromotellurous and Tridecabromotritellurous Acid Hydrates. Crystal Structures of the Oxonium Salts [H9O4]2[TeBr6] and [H9O4][Te3Br13]
Authors: Krebs Bernt , Bonmann Stefan , Erpenstein Klemens
Published: March 2015

From solutions of TeBr4 in concentrated aqueous HBr red needles of the crystalline hexabromotellurous acid with the stoichiometric composition H2TeBr6 · 8H2O (1) were isolated (space group P21/n, a = 7.662(5), b = 9.796(6), c = 11.987(8) Å, β = 91.35(4)° at 259 Κ). If the HBr:TeBr4 concentration ratio in the system TeBr4/HBr/H2O was kept low, a novel acid with formal composition HTe3Br13 ·4 H2O (2) could be prepared (space group Cm, a = 13.501(5), b = 15.453(6), c = 9.153(3) Å, β = 138.11(2)° at 140 Κ). The X-ray structural analysis of 1 shows the acid to contain, besides regular octahedral [TeBr6]2- ions (Te-Br: 2.671(4)-2.716(4) Å), [Η9Ο4]+ hydroxonium ions (O ··· O: 2.48(3)-2.62(3) Å). The [H9O4]+ units are linked through a hydrogen bond system (O ··· O: 2.80(3)-2.97(4) Å) to form a three-dimen-sional network. The formula has to be written as [H9O4]2[TeBr6]. 2 is the first acid in this class with a trinuclear anion. Its structural formula is [H9O4][Te3Br13]. As a fragment of the Te4Br,6 cube the anion consists of three edge-sharing octahedra with a central triply bridging Br. The mean bond distances are 2.515 Å for terminal Te-Br, 2.944 Å for Te-μ2Br and 3.077 Å for Te—μ3Br. The Ο···Ο distances in the isolated [H9O4]+ hydroxonium ions are 2.45(3)-2.57(2) A. Raman spectra of both acids are reported.
Notizen: 3-O-Methylpannaric Acid from the Lichen Roccella capensis
Authors: Huneck Siegfried , Jakupovic Jasmin , Follmann Gerhard
Published: March 2015

3-O-Methylpannaric acid is a new dibenzofuran from the lichen Roccella capensis (Roccellaceae); its structure has been established by spectroscopic and chemical methods.