bluuebunny/crossref_metadata_2025 huggingface dataset:
Zur Erzeugung von Silaethenen des Typus R2Si=CH(SiR3 ) und R2Si=CH2 durch thermische Salzeliminierung sowie zur Kenntnis von R2Si=CH(SitBu3) (R = Me, tBu ) / On the Generation of Silaethenes of the Types R2Si=CH(SiR3) and R2Si=CH2 by Thermal Salt Elimination and on the Knowledge of R2Si=CH(SitBu3) (R = Me, tBu)
Authors: Wiberg Nils , Finger Ch. M. M. , Passler T. , Wagner S. , Polborn K.
Published: February 2015

The generation of silaethenes Me2Si=CH(SiMe3) (1), Me2Si=CH(SitBu3) (2), tBuMeSi=CH(SitBu3) (3), and tBu2Si=CH2 (4) from metal organyls >SiX-CM< (X = Br, F; M = Na, Li) by elimination of MX is investigated. The metal organyls are prepared from >SiX-CBr< and RM (R = tBu3Si, nBu, Ph) by Br/M exchange (for preparation of >SiX-CBr< cf. Scheme 1). Only the sterically overcrowded silaethenes 2 and 3. generated from Me2SiF-CHNa(SitBu3) and tBuMeSiF-CHNa(SitBu3), have been identified by trapping with isobutene and dimethylbutadiene under formation of ene and Diels-Alder adducts. Analogous products are not found from Me2SiBr-CHNa(SiMe3) and tBu2-SiBr-CH2-Li. In the absence of trapping agents, compounds 1, 2, and 3 form cyclodimers. A reaction intermediate of the formation of 1 × 1 has been isolated and the structures of 2 × 2 and 3 × 3 have been solved by X-ray analysis. No dimer is observed for 4. In this case compounds are formed which may be interpreted as insertion products of 4 into the CLi bond of the precursor.
Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXX. 3-Hydroximino-1-alkyl(aryl)-isoindoline und 3-Hydroxylamino-1-alkyl(aryl)-1Hisoindole - Modellverbindungen für Struktur- und Reaktivitätsuntersuchungen - / Studies on the Chemistry of Isoindoles and Isoindolenines, XXXX. 3-Hydroximino-1-alkyl(aryl)-isoindolines and 3-Hydroxylamino-1-alkyl(aryl)-1Hisoindoles - Model Compounds for Investigations of Structure and Reactivity -
Authors: Clemens Andrea , Kreher Richard P. , Preut Johannes
Published: February 2015

3-Hydroximino-isoindolines and 3-hydroxylamino-1 H-isoindoles with substituents at the five membered ring have been prepared by condensation of substituted 3-alkoxy-1 H-isoindoles with hydroxylamine and O-/N -substituted hydroxylamines. Constitution and configuration of semi-cyclic amidoximes were derived from spectroscopic investigations and deduced on the basis of orientating chemical transformations. These results have been established by a crystal structure determination of a representative 3-hydroximino-isoindoline.
CuHo2[B2O5]2: Ein unerwarteter Strukturtyp in der Reihe der Kupferlanthanoidborate / CuHo2[B2O5]2: An Unexpected Structure Type in the Series of Copper Lanthanoid Borates
Authors: Wiesch A. , Bluhm K.
Published: February 2015

Single crystals of the new compound CuHo2 [B2O5]2 were obtained by using a B2O3 flux technique with CuO and Ho2O3 at 1050 °C. X-ray investigations on single crystals led to the space group P 21/c (Nr. 14) with lattice parameters a = 454.3(2); b = 726.0(4); c = 936.0(5) pm; β = 90.77(1)°; Z = 2. The compound is isotypic to CuTb2[B2O5]2 as well as to the gadolinite structure (FeY2[BeSiO5]2). The structure exhibits layer-like ∞
2[B2O5]4-, a two-dimensional anion consisting of edge sharing BO4 -tetrahedra, which form four- and eight-membered rings. The layers are connected by elongated CuO6-octahedra and slightly distorted tetragonal LnO8-antiprisms.
The Reaction of Bis[bis(trimethylsilyl)amino]germylene with Bromocyanogen and the Crystal Structure of Bis[bis(trimethylsilyl)amino]bromocyanogermane
Authors: Nikolaeva Svetlana N. , Avtomonov Evgeni V. , Lorberth Jörg , Petrosyan Valery S.
Published: February 2015

Bis[bis(trimethylsilyl)amino)]germylene (1) reacts with bromocyanogen to give bis[bis(trimethylsilyl)amino]bromocyanogermane (2). 2 crystallises from petroleum ether as a colourless solid which has been characterised by IR, 1H, 13C, 29Si NMR spectroscopy, ele­mental analysis and X-ray diffractometry.
Schwingungsspektren und Normalkoordinatenanalyse von Hexathiocyanatoplatinat(IV), Kristallstruktur von [Py2CH2][Pt(SCN)6] / Vibrational Spectra and Normal Coordinate Analysis of Hexathiocyanatoplatinate(IV), Crystal Structure of [Py2CH2][Pt(SCN)6]
Authors: Seemann J. , Preetz W.
Published: February 2015

By treatment of [PtCl6]2- with an excess of SCN– in aqueous solution [Pt(SCN)6]2- is formed. The X-ray structure determination on a single crystal of [Py2CH2][Pt(SCN)6] (orthor-hombic, space group Pna21, a = 15.5084(9), b = 11.8444(11), c = 13.2830(9)Å, Z = 4) shows, that the thiocyanate groups are exclusively S-coordinated with average Pt-S distances of 2.378 Å and Pt-S-C angles in the range from 103.1° to 108.1°. Based on the molecular parameters of the X-ray determination the low temperature (10 K) IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constant is fd(PtS) = 1.62 mdyn/Å.
The Crystal Structure of the Potential Ferroelectric Calcium Rhenate(VI, VII) Ca11Re4O24 and its Relation to the Structure of Sr11Os4O24
Authors: Jeitschko Wolfgang , Mons Horst A. , Rodewald Ute Ch. , Möller Manfred H.
Published: February 2015

The title compound was prepared in well-crystallized form by thermal decomposition of Ca5Re2O12. Its structure was determined from single-crystal X-ray diffractometer data: I41, a = 1107.0(1), c = 1609.3(1) pm, Z = 4, R = 0.056 for 4565 structure factors and 119 variable parameters. The calcium atoms occupy seven different sites with 8, 9, or 10 oxygen neighbors. The two different rhenium atoms are octahedrally coordinated by oxygen atoms with average Re-O distances of 193.1 and 187.7 pm for the six- and seven-valent rhenium atoms, respectively. The compound shows Curie-Weiss behavior with a magnetic moment of μexp = 1.15(±0.10) μB per Re(VI) atom. The structure is closely related to that of Sr11Os4O24 which, however, crystallizes in the space group I2/a. The difference between the two structures arises through the higher coordination numbers of the strontium atoms. It is suggested that at high temperature both compounds crystallize in the common higher symmetry space group I4/a. Since Ca11Re4O24 crystallizes in the pyroelectric class 4 this compound is expected to be ferroelectric.
Kristallstrukturen, 195Pt-NMR-Verschiebungen, Schwingungsspektren und Normalkoordinatenanalysen von trans-Dihalogeno-bis(oxalato)platinaten(IV), trans-[PtX2(ox)2]2-, X = Cl, Br, I / Crystal Structure, 195Pt NMR Chemical Shifts, Vibrational Spectra, and Normal Coordinate Analyses of trans-Dihalogeno-bis(oxalato)platinates(IV), trans-[PtX2(ox)2]2-, X = Cl, Br, I
Authors: Preetz W. , Uttecht J.-G.
Published: February 2015

By reaction of (n-Bu4N)2[Pt(ox)2] with elemental halogens in dichloromethane the complexes trans-[PtX2(ox)2]2- (X = Cl, Br, I) are formed. The crystal structures of trans-(py2CH2)[PtCl2(ox)2] · C4H6O3 (1) (monoclinic, space group P21/n, a = 12.119(3), b = 14.926(2), c = 12.666(4) Å, β = 91.26(3)°, Z = 4), trans-(py2CH2)[PtBr2(ox)2] (2) (monoclinic, space group P21/n, a = 7.402(8), b = 16.997(3), c = 14.898(3) Å, β = 98.15(3)°, Z = 4) and trans-(py2CH2)[PtI2(ox)2] ·C3H7NO (3) (orthorhombic, space group Pnma, a = 10.380(9), b = 13.973(2), c = 17.440(4) Å, Z = 4) have been determined by single crystal X-ray diffraction analysis. Highly resolution IR and Raman spectra were measured at low temperature (10 K). Using the molecular parameters of the X-ray determinations normal coordinate analyses based on a modified valence force field have been performed and the normal modes of vibration are assigned. The valence force constants are fd(PtCl) = 2.19, fd(PtBr) = 1.68, fd(PtI) = 1.28 mdyn/Å and fd(PtO) ranges from 2.71 to 2.82 mdyn/Å. The observed 195Pt NMR shifts are δ(195Pt) = 6472.4 (X = Cl), 6027.1 (Br) and 5142.7 ppm (I).
Synthese von Erdalkalimetallocenen aus Erdalkalimetall- bis[bis(trimethylsilyl)amid] und 6-Methyl-6-phenylfulven / Synthese von Erdalkalimetallocenen aus Erdalkalimetallbis[ bis(trimethylsilyl)amid] und 6-Methyl-6-phenylfulven Synthesis of Alkaline Earth Metallocenes from Alkaline Earth Metal Bis[bis(trimethylsilyl)amide] and 6 -Methyl-6 -phenylfulvene
Authors: Westerhausen Matthias , Hartmann Manfred , Makropoulos Nikolaos , Wieneke Birgit , Wieneke Michael , Schwarz Wolfgang , Stalkec Dietmar
Published: February 2015

The transmetalation of bis[bis(trimethyIsilyl)amino]stannylene in tetrahydrofuran with the alkaline earth metals yields the bis(tetrahydrofuran) adducts of calcium (1a), strontium (1b) and barium bis[bis(trimethylsilyl)amide] (1c). The metalation of 6-methyl-6-phenylfulvene with 1a, 1b and 1c gives 1,1′-bis(l-phenyl-ethen-l-yl)calcocene 2a, -strontocene 2b and -barocene 2c, respectively. The reaction of 1b with equimolar amounts of 6-methyl-6-phenylfulvene and acetophenone leads to the formation of bis[μ-[η5-1-(3-hydroxy-1-methyl-1,3-diphenyl-2- propen-1-yl )-2,4-cyclo -pentadien-l-yl](2-)-C,O:O]tetrakis(tetrahydrofuran-O)distrontium 3. The metathesis reaction of 2a with YCl3 and SnCl2 yields the corresponding yttrocenechloride 4 and stannocene 5. Crystallographic data of 1a: monoclinic, P21/c, a = 841.6(4), b = 1936.9(6), c = 1938.0(10) pm, β = 100.84(4)°, Z = 4, wR2 =0,1199); 1b: orthorhombic, Pbca, a = 1924.8(4), b = 1747.8(3), c = 1930.1(4) pm, Z = 8, wR2 = 0.1248; 3: monoclinic, P21/c, a = 1230.42(11), b = 1343.08(11), c = 1597.34(14) pm, β = 104.610(7)°, Z = 4, wR2 = 0.0980.
Kristallstruktur von MgSO3·H2O/Crystal Structure of Mg SO3·H2O
Authors: Buchmeier Willi , Engelen Bernward , Müller Holger
Published: February 2015

The crystal structure of MgSO3·H2O , space group P21 /ln, Z = 4, Dx = 2.415 g·cm-3 , a = 4.699(1), b = 12.751(3), c = 5.618(1) Å, β = 90.49(3)°, was determined by single crystal X-ray diffraction. MgSO3·H2O crystallizes in the MnSO3·H2O type. The structure consists of buckled trans layers ∞[MgSO3·H2O], which are built up from strongly distorted MgO5(H2O) octahedra sharing four equatorial vertices, and of trigonal pyramidal SO3
2- ions. It is close­ly related to the structures of orthorhombic MnSeO3·D2O and monoclinic ZnSeO3·H2O . The Mg-O distances range from 2.051(3) to 2.175(4) Å. The S-O distances (1.543(3), 1.547(3) and 1.493(3) Å) and the O-S-O angles (98.4(2) and 2x 106.0(2)°) correspond to those in MnSO3·H2O . The distortion of the MO5(H2O) octahedra (M = Mg, Mn) and of the SO3
2- ions is smaller in MgSO3·H2O , but with greater deviations from m symmetry. The distances between the H-connected ∞
2[MSO3·H2O] layers are greater in MgSO3·H2O , indicating weaker inter-layer hydrogen bonds. The lateral arrangement of the ∞
2[MSO3·H2O] layers is nearly the same in both sulfite monohydrates.
Synthesis of Spirocyclic Aminosilanes with Electron Withdrawing Substituents at Nitrogen
Authors: Wollenweber Markus , Keese Reinhart , Stoeckli-Evans Helen
Published: February 2015

The first synthesis of spirocyclic tetrasulfonamidosilanes is described. According to the X-Ray structure analysis of the most stable tetratosylamidosilane obtained the Silicon is bonded to four Nitrogen atoms in a spirocycle and surrounded by four Oxygen atoms which are located above the planes of the SiN4 tetrahedron.
Metallkomplexe mit biologisch wichtigen Liganden, XCVIII Cyclopalladierte Schiff-Basen von α-Aminosäure- und Peptidestern/Metal Complexes of Biologically Important Ligands, XCVIII Cyclopalladated Schiff Bases of α-Amino Acid and Peptide Esters
Authors: Böhm Andreas , Schreiner Bernhard , Steiner Norbert , Urban Reinhold , Sünkel Karlheinz , Polborn Kurt , Beck Wolfgang
Published: February 2015

The reactions of Schiff bases from benzophenone and α-amino acid and peptide esters with tetrachloropalladate afford the chloro bridged ortho palladated complexes 1-8 and 11-18. The chloro bridges are cleaved by P and N donors (PR3, pyridine, α-amino acid ester) to give the monomeric complexes 19-35. From 1, 2, 3 and bidendate ligands (dppe, α-amino carboxylates, cysteine methyl ester) the bis(chelates) 36-41, with N-diphenylmethylene glycylglycine ester the C,N,N chelates 46 and 47 are obtained.

The complexes 14, 23 and 47 were characterized by X-ray diffraction. Due to the two neighbouring five membered chelate rings in 47 a considerable distortion from the square planar coordination is observed.
Kristallstrukturen der iodierten closo-Hexaborate trans-(Ph4P)2[B6H4I2], mer-(Ph4P)2[B6H3I3] · 2 CH2Cl2, trans-(Ph4P)2[B6H2I4] · 2 CH3CN und (CH2Py2)[B6HI5]/Crystal Structures of the Iodized closo-Hexaborates trans-(Ph4P)2[B6H4I2], mer-(Ph4P)2[B6H3I3] · 2 CH2Cl2, trans-(Ph4P )2[B6H2I4] · 2 CH3CN and (CH2Py2)[B6HI5]
Authors: Sonnak D. , Preetz W.
Published: February 2015

X-ray structure determinations have been performed on single crystals of trans-(Ph4P)2-[B6H4I2] (1) (triclinic, space group P1̄, a = 9.9680(12), b = 10.9690(11), c = 11.0470(14) Å,α = 88.167(9), β = 80.466(12), γ = 68.839(11)°, Z = 1), mer-(Ph4P)2[B6H3I3] · 2 CH2Cl2 (2)(triclinic, space group P1̄, a = 11.8694(11), b = 15.1699(13), c = 17.051(2) Å, α = 75.118(9), β = 71.953(10), γ = 69.331(8)°, Z = 2), trans-(Ph4P )2[B6H2I4] · 2 CH3CN (3) (monoclinic, space group P21/n, a = 14.9665(10), b = 7.6783(10), c = 23.385(3) Å, β = 95.78(9)°, Z = 2), and (CH2Py2)[B6HI5] (4) (orthorhombic, space group Pnma, a = 13.660(2), b = 11.8711(13), c = 13.839(2) Å, Z = 4). The B6 octahedra are compressed in the direction of the B-I bonds, resulting in shortened diagonal B ··· B distances with average values of the groups I-B ··· B-I = 2.37 and I-B ··· B-H = 2.43 Å as compared with H-B ··· B-H = 2.49 Å.
The Promotive Properties of Alkali Metal Nitrate Melts for the Partial Oxidation of Methane to Methanol
Authors: Lee Bor-Jih , Kitsukawa Shigeo , Asakura Shukuji , Fukuda Kenzo
Published: February 2015

(Na, K)NO3 melts of various ratios were used as promoters for the partial oxidation of methane to methanol. Experiments were performed in a flow reactor system under atmo­spheric pressure and at various temperatures in the range of 525-600 °C. The influence of reaction temperature, melt composition, and reduced oxygen species on methane conversion and methanol selectivity were investigated systematically. The major reaction products were CH3OH, CO, CO2, and trace amounts of C2H6 and C2H4. A methane conversion of 1.8-12.4% and a methanol selectivity of 0.4-14.1% were obtained under these reaction condi­tions. Binary melts could achieve higher methanol selectivity than a single melt. The amounts of reduced oxygen species O2
- and O2
2-

were estimated from thermochemical data according to the ion equilibrium in molten nitrates. The promotive effect of nitrate melts was confirmed and the results indicate that superoxide O2
- plays an important role for methanol formation.
Untersuchungen an Polyhalogeniden, XXXIV Cäsium(18-Krone-6)dichloroiodat, [Cs(C12H24O6)]ICl2/Studies on Polyhalides, XXXIV Cesium (18 -crown -6 )dichloroiodate, [Cs(C12H24O6)]ICl2
Authors: El Essawi Mervat , Tebbe Karl-Friedrich
Published: February 2015

The new compound [Cs(18-crown-6)]ICl2 has been prepared by the reaction of cesium chloride and 18-crown-6 with iodine chloride in ethanol and structurally characterized by X-ray diffrac­tion methods. The geometries of the cation [Cs(18-crown-6)]+ and of the anion ICl2
- are as expected.
Isoselenocyanatoborate -Kristallstrukturen von (n-Bu4N)[BH(NCSe)3] und (Ph4P)[B3H7(NCSe)] / Isoselenocyanatoborates -Crystal Structures of (n-Bu4N)[BH(NCSe)3] and (Ph4P)[B3H7(NCSe)]
Authors: Steuer B. , Preetz W.
Published: February 2015

The treatment of [B6H6]2- with an excess of (SCN)2 in dichloromethane in the presence of solid KOH gives the hexaisoselenocyanatodiborate anion [B2(NCSe)6]2- as an intermediate (δ(11B) = -10.3 ppm), from which [BH(NCSe)3]- and elemental selenium are formed. The X-ray structure determinations on single crystals of (n-Bu4N)2[BH(NCSe)3] (1) (triclinic, space group Pi with a = 8.512(2), b = 10.885(3), c = 14.895(4) Å, α = 79.52(2), β = 74.86(2), γ = 86.768(2)°, Z = 2) and (Ph4P)[B3H7(NCSe)] (2) (monoclinic, space group C2, a = 7.686(5), b = 10.366(3), c = 17.533(3) A, β = 108.89°, Z = 4) show that the selenocyanate groups are coordinated exclusively via the N atoms with average bond lengths of B-N = 1.52, C-N = 1.15, C-Se = 1.75 A and angles N-C-Se = 179°, B-N-C = 168.7 - 176.8°. The N-B-N angles of 1 range from 107.5 to 109.5°.
Isolierte 1
∞[TeO5]-Oktaederketten im Bleitellurat Pb2TeO5 / Isolated 1
∞[TeO5] Chains of Octahedra in the Lead Tellurate Pb2TeO5
Authors: Wedel B. , Wulff L. , Müller-Buschbaum Hk.
Published: February 2015

Single crystals of Pb2TeO5 have been prepared by flux techniques. X-ray investigations showed a new crystal structure with monoclinic symmetry, space group C4
S -Cc, a = 13.099(3), b = 5.714(1), c = 7.520(2) Å, β = 123,80(3)°, Z = 4. Pb2TeO5 is characterized by 1
∞[TeO5] chains of octahedra isolated from each other and incorporated into an edge, corner and face connected frame of PbO7 polyhedra. Possible positions of the lone pair of electrons of Pb2+ are estimated by calculations of Coulomb terms of lattice energy.
Synthesis and Reactions with CO and C2H4 of Cobalt(I) Complexes Containing Trimethylphosphine and Chelating o-Diphenylphosphanyl- phenolate Ligands
Authors: Klein Hans-Friedrich , Brand Alexandra , Cordier Gerhard
Published: February 2015

In tetracoordinate cobalt(I) halide compounds CoX(Ph2P⌒O H)(PMe3)2 (X = CI, Br) o-phos-phanylphenols PhaP⌒OH are coordinated as phosphane ligands. In the presence of base chelat­ ing anions Ph2P⌒O- give rise to pentacoordinate com plexes Co(Ph2P⌒O)(PMe3)3. Molecular structures are presented for both types of compounds. The five-membered chelate ring in Co(Ph2P⌒O)(PMe3)3 is resistant to protonation, and ring-opening is not observed in the presence of CO or C2H4. Replacing one of the trimethylphosphanes by one of the π-acceptor ligands affords fluxional complex molecules which upon cooling attain definite ground-state geometries out of a multitude of possible isomers.
Bonding in an Unusual Nickel Carbide
Authors: Merschrod Erika E , Tanga S. Huang , Hoffmann Roald
Published: February 2015

The bonding in an unusual nickel carbide polymer network synthesized by Musanke and Jeitschko is analyzed using qualitative, band-structure calculations in the framework of extended Hiickel tight-binding theory. The carbide features infinite, one-dimensional, vertex-sharing chains of Ni squares. Each square is centered by a carbon and flanked by C2 units.

- In this electron-rich polymer, the Ni atoms act as electron acceptors through their s and p orbitals. The orbital interaction schemes reveal that there is little Ni-Ni bonding and essentially no Ni to C2 back-donation. Molecular orbital interaction diagrams of some molecular models are used to describe the bonding in 1
∞[Ni3Cs]8-.

We also discuss the stability of the planar building block of the polymer, (CNi4)4- (which resembles planar CH4) with respect to a “tetrahedral” alternative and we do so for the extended 1
∞[ Ni3C]4-and 1
∞[Ni3C5]8-chains. In each model case the tetrahedral alternative is favored, and there is no sign of stabilization of a crucial CL4 orbital. Such stabilization is partially achieved through bonding to two Ca axial to the C in the center of the Ni4 ring, but it takes the entire inter-chain calcium network to effect the observed stabilization.
Solventothermal Synthesis of the Lamellar Selenidostannates(IV) A2Sn4Se9 · H2O (A = Rb, Cs) and Cs2Sn2Se6
Authors: Loose Anja , Sheldrick William S.
Published: February 2015

Reaction of A2CO3 with Sn and Se in an H2O/CH3OH mixture at 115 - 130°C affords the isotypic lamellar selenidostannates A2Sn4Se9-H2O 1 (A = Rb) and 2 (A = Cs). The polyanions 2
∞[Sn4Se9
2-] exhibit Sn4Se5 es molecular building units, in which two adjacent Sn(IV) atoms of an Sn4Se4 8-membered ring are bridged by an additional Se atom. These units connect through (SnSe)2 4-membered rings to afford a 44 anionic net with 16-membered cavities. Cs2Sn2Se6 (3) may be prepared by methanolothermal reaction of Cs2CO3 with SnSe and Se at 130°C and contains porous 2
∞[SnTSe2- ] sheets in which 1
∞[SnSe3
2- ] ribbons are linked through Se-Se bonds. The resulting 44 net displays 14-membered pores in which the Cs cations reside.
Cyclodisilazane in cis-Konformation -eine einfache Synthese / Cyclodisilazanes in cis Conformation -a Facile Synthesis
Authors: Klingebiel Uwe , Tecklenburg Brigitte , Noltemeyer Mathias , Schmidt-Bäse Dieter , Herbst-Irmer Regine
Published: February 2015

Dilithium derivatives of bis(silylamino)fluorosilanes (1-3) react with chlorotrimethylsilane to give dilithium derivatives of the corresponding bis(silylamino)chlorosilanes and Me3SiF. LiCl-elimination in the presence of THF leads to the formation of silaamidides, which are isolated as dimers, four-membered cyclosilazane anions. (R′Si-NR)2Li(NR)2
㊀’, Li(THF)4㊉ (4, 6), and (THF)3Li-ClLi(THF)3
㊉ (5) cations. Hydrolysis of the dimeric silaamidides is the only but facile synthesis of cyclodisilazanes in cis-conformation (7 - 9). 1, 4, 7: R = Si(CMe3)2Me, R′= F; 2. 5. 8: R = SiMe2CMe3, R′= CMe3; 3, 6, 9: SiMe2CMe3, R = C6H5.
The Molecular Structures and Conformational Preferences of Bis(dimethylstibyl)-Sulfane and -Tellurane, E(SbMe2)2, E = S or Te, Me = CH3, by Density Functional Theory Calculations and Gas Electron Diffraction
Authors: Haaland Arne , Shorokhov Dimitry J. , Volden Hans Vidar , Breunig Hans Joachim , Denker Michael , Rösler Roland
Published: February 2015

Density functional theory calculations on E(SbMe2)2, E = S or Te, Me = CH3, indicate that the equilibrium structures are syn-syn or near syn-syn conformers with overall C2v or C2 symmetry. The calculations further indicate the existence of syn-anti conformers about 4 kJ mol-1 (E = S) or 1 kJ m ol-1 (E = Te) above the equilibrium structure. G as electron diffraction data show that both conform ers are present in gaseous S(SbMe2)2, while the presence of the syn-anti conformer in gaseous Te(SbMe2)2 is uncertain. The Sb - S and Sb - Te bond distances are 241.4(4) and 278.1(3) pm, respectively, the valence angles of the synsyn conformers are <SbSSb = 9 8.7(5)° and <SbTeSb = 91(2)°.
Reaction of 9-Borabicyclo[3.3.1]nonane with N-Trimethylsilylamines – Cleavage of the N–Si or N–H Bond
Authors: Wrackmeyer Bernd , Kehr Gerald , Alib Saqib
Published: February 2015

The reaction of dimeric 9-borabicyclo[3.3.1]no-nane 1 with N-trimethylsilyl-aniline 2 affords 9-anilino-9-borabicyclo[3.3.1]nonane 5 by elimina­tion of trimethylsilane. In contrast, 1 reacts with the N-trimethylsilyl-2-aminopyridines 3 and 4 se­ lectively by elimination of H2 to give the corre­sponding N-trimethylsilyl-aminoboranes 6 and 7. The latter reactions proceed via formation of bo-rane-pyridine adducts.
Phasenbeziehungen und Chemischer Transport der Verbindungen im ternären System Re/Mo/O / Phase Relations and Chemical Transport of the Compounds in the Ternary System Re/Mo/O
Authors: Feller J. , Oppermann H , Kucharkowski R , Däbritz S
Published: February 2015

In the ternary system Re/Mo/O four series of mixed oxides have been prepared by heating of powder samples and by transport reactions. The series are derived from the oxides ReO2, MoO2, γ-Mo4O11 und η-Mo4-O11 and have compositions Re1-xMoxO2 (0 < x < 0.37), Mo1-yReyO2 (0 < y < 0.42),γ -Mo4-z1Rez1O11 (0 < z1 < 1), and η-Mo4-z2Rez2O11 (0 < z2 < 1). Contributions to the understanding of the transport mechanism were obtained from thermodynamic calculations. The composition of the mixed crystals obtained have been determined by EPMA and ICP-AES.
Koordinationsambidenz des Thiocyanations in Alkalitrithiocyanatomanganat(II)-Hydraten / Coordination Ambidence of the Thiocyanate Anion in Alkali Trithiocyanatomanganate(II) Hydrates
Authors: Biedermann Matthias , Hartung Helmut , Böhland Heinz , Matthäus Regina
Published: February 2015

Alkali metal trithiocyanatomanganate(II) hydrates have been prepared and characterized by several analytical methods. The structures of NH4[Mn(NCS)3(H2O)] (1a), K [Mn(NCS)3(H2O)] (1b) and Na[Mn(NCS)3] · 3 H2O (2) could be elucidated by X-ray analysis, 1a and 1b are isotypic and form a polymeric layer structure which is characterized by the ambident nature of the thiocyanate ligand and binding of the water molecule to the octahedrally coordinated Mn atom. In 2 the complex manganate(II) anions form a layer structure with trigonal symmetry in which each Mn atom is connected with three Mn neighbours by thiocyanate double bridges. The cation partial lattice consists of infinite chains of face-sharing [Na(H2O)6]+ octahedra running perpendicular to the anion layers.
Charge Transfer Interaction in (Riboflavin)tricarbonylrhenium(I) Chloride
Authors: Kunkely Horst , Vogler Amd
Published: February 2015

[Re(riboflavin)(CO)3Cl] shows intraligand (λmax = 476 and 518 nm) and Re(I) to π* (riboflavin) metal-to-ligand charge transfer, MLCT, (λmax = 556 nm, in CH3CN) absorptions in close proximity. The MLCT band undergoes a moderate solvent-dependent shift (negative solvatochromism) indicating a partial charge separation in the excited state. The complex is not photoluminescent.
Neue Synthesen mit Magnesiumhydrid. Teil 3: Herstellung nanokristalliner und amorpher Metalle durch Hydridreduktion / New Syntheses with Magnesium Hydride. Part 3: Preparation of Nanocrystalline or Amorphous Metals by Hydride Reduction
Authors: Knott Wilfried , Georg Frommeyer Georg , Klapdor Astrid , Windbiela Dagmar
Published: February 2015

The tribochemical reduction of metal halides by magnesium hydride in organic solvents allows the synthesis of nanosize or amorphous metals.
Absolute Configuration of Chiral 1,3,4,5-Tetrahydro-2H-l,5-benzodiazepin-2-ones
Authors: Hasan Mashooda , Nizami Tanveer Ahmad , Malik Abdul , Ohlendorf Claus , Hiller Wolfgang , Wolfgang Voelter Wolfgang
Published: February 2015

X-ray studies are carried out to correlate the Cotton effects in CD spectra with the absolute configuration of a series of previously reported chiral 1,3,4,5-tetrahydro-2H-1 ,5-benzodazepin-2-ones.
Utility of Cyano Acid Hydrazide in Heterocyclic Chemistry: A New Route for the Synthesis of New 1,2,4-Triazolo[1,5-a]pyridines and 1,2,4-Triazolo[1,5-a]isoquinolines
Authors: Hussein Abdel Haleem Mostafa
Published: February 2015

Cyano acid hydrazide 1 was condensed with cyclohexanone in refluxing ethanolic piperidine to yield the hydrazone 4. Compound 4 reacts with arylidines 5a-i to yield the 1,2.4- triazolo[1,5-a]pyridines 7a-i. Compound 4 also reacts with mixtures of aliphatic aldehydes and different active methylene reagents to yield 1,2,4-triazolo[1,5-a]pyridines 8a-d. Similarly reaction of 4 with arylazomalononitrile to yield the triazolopyridines 10a-d Reaction of 4 with aromatic aldehydes gives 12a-e. Compound 8a reacts with elemental sulfur to yield the thieno-1,2,4-triazolopyridine 13. This underwent cycloaddition with acrylonitrile, ω-nitrostyrene, chalcone, N-phenylmalemide, dimethylacetylenedicarboxylate and tetracyanoethylene yielding the isoquinolines 15-18. All new compounds have been characterized by their IR. 1H NMR and mass spectra.
Gold(I)-Komplexe mit Aminliganden, II. (Methylpyridin)-Komplexe von Gold(I) Gold(I) / Complexes with Amine Ligands, II. Methylpyridine Complexes of Gold(I)
Authors: Jones Peter G. , Ahrens Birte
Published: February 2015

Gold(I) complexes of overall formula LAuCl (L = various methylpyridines) are non-conducting in acetone. X-ray structure analyses show that the solid state structure of the cor­ responding complex 1 (L = 2-picoline) is molecular; the 3-picoline derivative 2 is however ionic (L2Au)+(AuCl2)-. 3-Picoline forms a molecular complex LAuC6F5 (3) and also the ionic (L2Au)+(SbF6)- (4). Complexes 1, 2 and 4 display short Au ··· Au contacts, leading to chains of gold atoms; additionally, complexes 3 and 4 show weak Au ··· F contacts. The (3-picoline)-gold(III) complex trans-(L2AuCl2)+(SbF6)- (5) was obtained as a by-product; it too contains short Au ··· F contacts.
Ternary Intermetallic Compounds LnMn2Al10 (Ln = Y, La-Nd, Sm, Gd-Dy) and LnRe2Al10 (Ln = Ce, Pr, Sm) with CaCr2Al10-Type Structure
Authors: Thiede Verena M.T. , Jeitschko Wolfgang
Published: February 2015

The twelve title compounds have been prepared for the first time. Their CaCr2Al10-type structure (P4/nmm, Z = 4) was refined from single-crystal X-ray data for the three representatives TbMnAl10 (a = 1274.3(2) pm, c = 511.4(2) pm, R = 0.025 for 680 structure factors F and 43 variable parameters V), CeRe2Al10 (a = 1295.5(5) pm, c = 517.2(4) pm, R = 0.054 for 810 F and 46 V), and SmRe2Al10 (a = 1291.5(2) pm, c = 516.5(1) pm, R = 0.021 for 622 F and 46 V). The atomic positions of the lanthanoid and transition metal atoms are fully occupied. Significant deviations from the full occupancies were observed for two aluminum sites in TbMn2Al10 and for all five aluminum sites of the two rhenium-containing compounds, resulting in the compositions TbMn2Al9.63(2), CeRe2Al9.52(8), and SmRe2Al9.16(9). The cell volume of CeRe2Al10 and to a smaller extent also that of CeMn2Al10 indicate mixed or intermediate +III/+IV valencies of the cerium atoms in these compounds. The structural relationships between the three closely related body-centered tetragonal structures of ThMn12, CeMniAl8, DyFe6Al6 and the primitive tetragonal structure of CaCr2Al10 are briefly discussed.
Crystal Engineering towards Design of Macrocyclic Coordination Compounds: Crystal Structure of Rubidium Tetrachloro-and Tetracyanoaurate(III) Complexes with 18-Crown-6
Authors: Manskaya Julia A. , Domasevitch Konstantin V. , Ponomareva Vera V. , Sieler Joachim , Kokozay Volodimir N.
Published: February 2015

The new macrocyclic complexes of composition Rb(18-crown-6)AuX4 (X = Cl (1) and CN (2)) have been prepared and characterized by X-ray crystallography (1: monoclinic, space group P21/n, with a = 8.747(1), b = 8.366(1), c = 15.404(1) Å; β = 104.37(1)°, V = 1092.0(3) Å3 , Z = 2; final R1 =0.025 for 2030 independent reflections used; 2: monoclinic, space group P21/c, with a = 14.765(3), 6 = 17.134(3), c = 8.855(2) Å; β = 90.20(1)°, V = 2240.2(8) Å3, Z = 4; final R1 = 0.080 for 2034 independent reflections used). Both structures consist of Rb(18-crown-6)+ cations (A) and complex aurate(III) anions AuX4
- (B). Complex 1 has a linear polymeric array -A-B-A-B-(Rb-Cl 3.604(3), 3.654(3) Å) with the rubidium ions disordered 0.276(2) Å above and below the crown ether plane (Rb-O 2.819(5)-2.884(5) Å, av. 2.846(5) Å). The positioning of the rubidium atom away from the center of the 18-crown-6 is effected by the packing of the Rb(18-crown-6)+ and AuCl4
- moieties, and by the resemblance in the charge and symmetry of the cationic and anionic parts of the structure. Complex 2 has a zig-zag polymeric array -A-B-A-B-(Rb-N 2.92(2), 2.94(1) Å) with orthogonal disposition of Rb(18-crown-6)+ and Au(CN)4
- planes. The rubidium atom is situated 0.90(2) Å above the mean plane of the macrocyclic oxygen atoms (Rb-O 2.93(5)-3.15(4) Å) and adopts a typical “sunrise coordination”.
Strukturuntersuchungen an Dihalogen(diphosphan)nickel-KompIexen in Lösung mit Differential-Puls-Polarographie / Structure Analysis of Dihalogeno(diphosphine)nickel Complexes in Solution with Differential Puls Polarography
Authors: Mutz Martin , Latscha Hans Peter
Published: February 2015

The structures of twelve dihalogeno(diphosphine)nickel complexes of the general formula [NiX2(PR′2R′)2] (X = Cl, Br and I; R′ resp. R″ = -C2H5 or -C6H5) were analyzed in solution by differential puls polarography and 1H-NMR spectroscopy as a function of temperature.
Festphasensynthese von Muramyldipeptiden an isomeren Trialkoxybenzylamin-Harzen / Solid Phase Synthesis of Muramyl Dipeptides on Isomeric Trialkoxybenzylamine Resins
Authors: Kohlbaua Hans-Jürgen , Tschakert Jochen , Al-Qawasmeh Raed A. , Nizamì Tanveer Ahmad , Malik Abdul , Voelter Wolfgang
Published: February 2015

New isomeric trialkoxybenzylamine resins are developed coupling phthalimidomethyl-3,5-dimethoxyphenols to the Merrifield resin, followed by subsequent treatment with hydrazine. The generated benzylamine function allows DCC coupling w ith the carboxyl function of amino acids and peptides which are removed as amides after treatment with trifluoroacetic acid. These new trialkoxybenzylamine resins allow expeditious syntheses of peptide amides and glycopeptide amides as is demonstrated for muramyl peptides and analogues.
Variations in the Chain Structure of Cationic (Phosphine)gold(I) Dialkyldithiophosphate Complexes
Authors: Preisenberger Max , Schier Annette , Schmidbaur Hubert
Published: February 2015

Treatment of dithiophosphoric acid diesters (RO)2P(S)SH with appropriate quantities of tris[(phosphine)gold(I)]oxoniumtetrafluoroborates {[(R′3P)Au]30}+ BF4- in dichloromethane gives di-or trinuclear complexes of the types {(RO)2P[SAu(PR3)]2/3}+/2+ (2) BF4- as colour­ less, crystalline salts. As determined by single crystal X-ray diffraction studies, in the 1:2 complexes (with R = R′ = Me and R′ = Et, R = Ph and o-Tol), each gold atom is attached to a different sulfur atom, but with short intracationic Au-Au contacts. These cations are associated to form strings through intermolecular Au-Au contacts in the first case (R = Et), but through additional Au-S contacts in the second (R = Ph). For R = o-Tol, the cations are not associated at all owing to steric hindrance. This result is indicative of very small energy differences between the two modes of association. The 1:3 complexes are fluxional in solution and show virtually equivalent R3PAU groups in the NMR spectra at 20°C, but at low temperature non-equivalent ligands can be distinguished as shown previously for analogous dithiophosphinate derivatives.
Wechselwirkungen in Molekülkristallen, 143. ortho-Benzol-Derivate mit ineinander verzahnten Chlormethyl-und Methylamino-Substituenten: Strukturen und Rotationsenthalpie-Hyperflächen/ Interactions in M olecular Crystals, 143. ortho-Benzene Derivatives with M eshed Cogwheel Chlorom ethyl and Methylamino Substituents: Structures and Rotation Enthalpy Hypersurfaces
Authors: Bock Hans , Nagel Norbert
Published: February 2015

Facets of molecular dynamics in organic compounds such as coupled rotations of adjacent substituents are advantageously discussed based on structural data. Within this context, crystal structures of spatially overcrowded ortho-disubstituted benzene derivatives with chloromethyl or methylamino groups are presented together with semiempirical enthalpy hypersurfaces for the substituent rotation. Both compounds, 1 -trichloromethyl-2-dichloromethyl-benzene as well as l-trimethylammonium-2-dimethylamino-benzene exhibit comparable steric overcrowding and their preferred dynamics are predicted to be dominated by the rotation of the threefold substituted group during an approximate standstill of the twofold substituted, mirror-symmetric one. According to known solid state NMR measurements as well as to atom/atom-potential model calculations for the pentachloro ortho-xylene derivative, this molecular dynamic mode is still active in the crystal.
Darstellung, spektroskopische Charakterisierung und Kristallstruktur von Dicyclopentadienylcobalt-hexahydro-closo-hexaborat [(C5H5)Co(C5H4)B6H5Hfac]/ Synthesis, Spectroscopic Characterization and Crystal Structure of Dicyclopentadienyl- cobalt-hexahydro-closo-hexaborate [(C5H5)Co(C5H4)B6H5Hfac]
Authors: Schaper T. , Preetz W.
Published: February 2015

By reaction of [B6H6Hfac]- with cobaltocene in acetonitrile [(C5H5)Co(C5H4)B6H5Hfac] is formed. Its crystal structure has been determined by single crystal X-ray diffraction analysis (monoclinic, space group P21/n with a = 9.786(2), b = 9.726(2), c = 13.938(2) A, β = 107.2850(3)°, Z = 4). The B6 octahedron is slightly compressedoin the direction of the B-C bond by about 1%, with B-B bond lengths between 1.69 and 1.87 A. The 11B NMR spectrum exhibits a 1:4:1 pattern of a monosubstituted B6 cage. In the IR and Raman spectra characteristic B-H vibrations are observed.
A New Synthesis of Tetrakis(C-methyl)octakis(hydroxyethyl)calix[4]- resorcinarene via an Ethoxy-Tethered Trimethylsiloxy Precursor
Authors: Neda Ion , Siedentop Tjark , Vollbrecht Alexander , Thönnessen Holger , Jones Peter G. , Schmutzler Reinhard
Published: February 2015

The octakis(trimethylsiloxy)calix[4]resorcinarenes, 3 and 4, were synthesized by reaction of 1 and its tetrabromo derivative 2 with hexamethyldisilazane, and were found to exhibit dynamic behaviour in solution. Temperature-dependent NMR investigations confirmed the presence of at least two conformational isomers of 3 in solution. The conformation of 3 in the solid state was determined by an X-ray crystal structure analysis; the calixarene displays a boat conformation.

The introduction of the ethoxy group as a spacer into the molecule of 1 was effected via its reaction with ethyl bromoacetate and subsequent reduction with lithium aluminium hydride forming the ethoxy-tethered C-methylcalix[4]resorcinarene 6 in an impure state. Reaction of crude 6 with hexamethyldisilazane furnished the ethoxy-tethered octakis( trimethylsiloxy)calix[4]resorcinarene 7; its hydrolysis led to pure 6.
Kohlensäurebis(trimethylsilyl)ester: Spektroskopische Charakterisierung und verbesserte Darstellung/ The Bis(trimethylsilyl)ester of Carbonic Acid: Spectroscopic Characterization and Improved Preparation
Authors: Minkwitz Rolf , Schneider Stefan
Published: February 2015

Keywords

The low temperature preparation of the bistrimethylsilylester of carbonic acid is reported. The hydrolysable and thermolabile (Me3SiO)2CO has been characterized by vibrational and NMR spectroscopic methods. Under inert conditions the (Me3SiO)2CO is stable at 233 K for several weeks.
Electrochemical Study of Tricarbonyl(η6-cyclooctatetraene)metal(0) Complexes of the Group 6 Elements
Authors: Yilmaz Giirkan Atinç , Önal Ahmet M. , Özkar Saim
Published: February 2015

Tricarbonyl(η6-cyclooctatetraene)metal(0) complexes of the group 6 elements were prepared by using the procedures described in the literature with some minor modifications and identi­fied by IR and NMR spectroscopy. Their electrochemical behavior was studied by using cyclic voltammetry in dichloromethane solution containing 0.1 M tetrabutylammonium tetrafiuorob-orate as supporting electrolyte. Their oxidation and reduction potentials were measured and discussed in terms of the frontier energy levels in connection with the UV-Visible electronic ab­ sorption spectral data. In order to elucidate the mechanism of electrooxidation of the complexes, constant potential electrolysis was performed for one representative example, tricarbonyl(η6-cyclooctatetraene)chromium(O). The IR monitoring of the reaction showed that it is gradually converted to hexacarbonylchromium(O) upon electrolysis at constant potential.
Über die Reaktion von Bis(t-butylamino)dimethylsilan mit Titantetrachlorid. Kristallstrukturen des Imido-Komplexes [TiCl2(N-CMe3)(H2 N-CMe3)(CH3CN)]2 und des Ketimido-Komplexes [TiCl3 {NC(Me)N(H)CMe3}(CH3CN)2]/ On the Reaction of Bis(t-butylamino)dimethylsilane with Titanium Tetrachloride. Crystal Structures of the Imido Complex [TiCl2(N-CMe3)(H2N-CMe3)(CH3CN)]2 and of the Ketimido Complex [TiCl3{NC(Me)N(H)CMe3}(CH3CN)2]
Authors: Mommertz Andreas , Leo Roland , Massa Werner , Dehnicke Kurt
Published: February 2015

The reaction of bis(t-butylamino)dimethylsilane with titanium tetrachloride in dichloromethane solution leads to a mixture of compounds from which the imido complex (H3NCMe3)2[TiCl3(N-CMe3)]2 (1) and by extraction of the residue with acetonitrile the imido complex [TiCl2(N-CMe3)(H2N-CMe3)(CH3CN)]2 (2) can be isolated. 1 reacts with acetonitrile to give the ketimido complex [TiCl3{NC(Me)N(H)CMe3}(CH3CN)2] (3). According to crystal structure determinations 2 consists of centrosymmetric dimeric molecules containing TiCl2Ti bridges, the N-CMe3
2- ligands being in equatorial positions with TiN bond lengths of 168.8(4) pm which corresponds to double bonds. In the monomeric complex 3 the chloro ligands are in meridional positions of the distorted octahedrally coordinated titanium atom with a TiN bond length of 175.7(2) pm of the ketimido ligand.
Metal Ion-Binding Properties in Aqueous Solution of the Nucleoside Analogue, 5,6-Dichloro-1-(β-ᴅ-ribofuranosyl)benzimidazole (DRB)
Authors: Kapinos Larisa E. , Song Bin , Sigel Helmut
Published: February 2015

The stability constants of the 1:1 complexes formed between Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ or Cd2+ (= M2+) and 5,6-dichloro-l-(β-ᴅ-ribofuranosyl)benzim idazole (DRB) were determined by potentiom etric pH titrations in aqueous solution (25 °C; I = 0.5м, NaNO3). The acidity constant of H(DRB)+, the proton being at N3, was measured by the same method and the result was confirmed via spectrophotometry. Based on previously established [L. E. Kapinos, B. Song, H. Sigel, Inorg. Chim . Acta 280, in press (1998)] logм
мʟ versus Kʜ
ʜʟ straight-line plots for complexes of imidazole-type ligands it is shown for the Mn(DRB)2+ and Zn (DRB)2+ complexes, as examples, that the benzene ring of the benzim idazole residue exerts a steric inhibition for metal ion binding at N3; i.e., the data points for the M(DRB)2+ complexes fall clearly below the straight lines defined by the imidazole- type ligands.
Gesteuerte Kristallisation des Gadolinium(III)-Komplexes von Diethylentriaminpentaacetat: Monomere und dimere Struktur / Controlled Crystallization of the Gadolinium(III) Complex of Diethylenetriamine-Pentaacetate: Monomeric and Dimeric Structure
Authors: Ruloff Robert , Gelbrich Thomas , Hoyer Eberhard , Sieler Joachim , Beyer Lothar
Published: February 2015

We present the preparation and X-ray crystal structures of two gadolinium(III) complexes of the ligand diethylenetriamine pentaacetic acid (H5dtpa). With two equivalents of guanidinium (gu+) per equivalent of complex we obtained the dimer (gu)4[Gd2(dtpa)2]·(gu)HCO3 , and with one equivalent of aminoguanidinium (agu+) the monomer (agu)[Gd(Hdtpa)(H2O)]·2H2O , both with the metal atoms in a coordination number of 9. The dimer contains no coordinated water molecule. The monomer is present as two crystallographically independent complexes hydrogen-bridged via carboxylate oxygen atoms (O···O 2.48 Å; O-H···O 172°) and with Gd-Ocoord. water distances of 2.418(4) and 2.423(4) Å, respectively.
Synthesis and Crystal Structure of a Novel Germatrane: 1-Bis(trimethylsilyl)aminogermatrane
Authors: Nikolaeva Svetlana N. , Megges Klaus , Lorberth Jörg , Petrosyan Valery S.
Published: February 2015

1-Bis(trimethylsilyl)aminogermatrane (3), the first germatrane bearing an amino group at the germanium atom, was synthesized by the reaction of 1 -hydroxygermatrane with bis[bis(trimethylsilyl)amino)]stannylene (1). 3 has been characterised by 1H ,13C, 29Si NMR spectroscopy, elemental analysis, and by X-ray diffractometry.
Kristallstrukturen von Me2Si[N(SiMe3)2]2 und [Me2Si(NPh)(NHPh)Li·OEt2]2 / Crystal Structures of Me2Si[N(SiMe3)2]2 and [Me2Si(NPh)(NHPh)Li·OEt2]2
Authors: Mommertz Andreas , Geiseier Gertraud , Harms Klaus , Dehnicke Kurt
Published: February 2015

Abstract The crystal structures of the title compounds are reported. Me2Si[N(SiMe3)2]2: Space group Pbcn, Z = 4, lattice dimensions at 213 K: a = 1487.8(1), b = 1299.4(1), c = 1259.7(1) pm. The compound forms monomeric molecules with crystallographic C2 symmetry and Si-N bond lengths of 177.9(3), 171.6(3) and 175,2(3) pm. [Me2Si(NPh)(NHPh)Li·OEt2]2: Space group P21/n, Z = 2, lattice dimensions at 190 K: a = 1082.7(3), b = 1038.8(2), c = 1641.3(4) pm, β = 91.350(3)°. The compound forms centrosymmetric dimeric molecules in which the lithium atoms are members of a Li2N2 ring with Li-N bond lengths of 206.6(2) and 213.5(2) pm. The hydrogen atom at the nitrogen atom of the HNPh- group is not involved in hydrogen bridging bonds.
Supersilylverbindungen des Phosphors, V [1]. Darstellung, Struktur und Reaktivität des Pentaphosphids (tBu3Si)3P5Na2 und des Pentaphosphans (tBu3Si)3P5[2] / Supersilyl Compounds of Phosphorus, V [1]. Preparation, Structure, and Reactivity of the Pentaphosphide (tBu3Si)3P5Na2 and the Pentaphosphane (tBu3Si)3P5 [2]
Authors: Wiberg Nils , Wörner Angelika , Lerner Hans-Wolfram , Karaghiosoff Konstantin , Nöth Heinrich
Published: February 2015

The orange THF adduct (tBu3Si)3P5Na2 (THF)4 of the pentaphosphide (tBu3Si)3P5Na2 (3) has been prepared, (i) by protolysis of the tetraphosphide (tBu3Si)2P4Na2(THF)n (2) with CF3CO2H in THF (molar ratio 2 : 1 ) , (ii) by dissolving crystalline 2 in toluene, and (iii) by the reaction of P4 with tBu3SiNa(THF)2 in benzene (molar ratio 1 : 4). According to an X-ray structural analysis, the THF adduct of 3 contains a P3 ring with two PNa(SitBu3) substituents in cis position and one SitBu3 substituent in trans position to the former groups. The protolysis of 3 with CF3CO2H leads to the pentaphosphane P5H2(SitBu3)3 (9), the silylation of 3 with Me2SiCl2 to the pentaphosphane P5 (SiMe2)(SitBu3)3 (10), and the oxidation of 3 with C2(CN)4 to the pentaphosphane P5(SitBu3)3 (5). The structures of 3,5,9, and 10 have been assigned from 31P and 29Si NMR data. The pentaphosphane 5 contains a hitherto unknown P5 backbone of a P3 ring anellated with a P4 ring.
Optimized Automated Solid Phase Synthesis of Oligonucleotides and Derivatives
Authors: Urbina Gabriel Alvarado , Grübler Gerald , Weiler Angelika , Echner Hartmut , Stoeva Stanka , Schernthaner Johann , Gross Waleri , Voelter Wolfgang
Published: February 2015

An optimized automated synthesizer is presented for assembling oligonucleotides, thiooligonucleotides and 5′-modified oligonucleotides including: chemical phosphorylation, multihydroxyl derivatization with a non-nucleosidic phosphoramidite. The incorporation of biotin, fluorescein and rhodamine phosphoramidites is described. The purification and structure determination of oligo-nucleotides was confirmed using high performance liquid chromatography (HPLC), capillary electrophoresis (CE) and laser desorption mass spectrometry (LDMS). Several applications and confirming data will be presented for gene synthesis and polymerase chain reaction (PCR) experiments.
Solvothermal Synthesis and Crystal Structure Determination of Tris- (ethyleneamine-ammonium) Tetraselenoantimonat: Non-Centrosymmetry Mediated by an Extended Unusual N-H···N Hydrogen Bonded Network?
Authors: Wendland Frank , Näther Christian , Schur Michael , Bensch Wolfgang
Published: February 2015

The title compound has been synthesized under solvothermal conditions by the reaction of elemental chromium, antimony and selenium in a solution of 40% 1,2-ethanediamine (en) in methanol. The crystal structure consists of tetrahedral SbSe4
3- anions which are connected by monoprotonated 1,2-ethanediamine (enH+) cations via N-H--Se hydrogen bonding. The enH+ cations are joined via strong N-H -N hydrogen bonds between the ammonium hydrogen and the amino nitrogen atom forming four distinct chains, each built up of three crystallographically independent enH+ cations. Two of these chains are running parallel to [100], the other two are parallel to [010]. Based on this arrangement different centrosymmetric or non-centrosymmetric hydrogen bonding patterns are possible, but only in one chain the sequence of NH2 and NH3
+ groups was determined by X-ray diffraction
Zur Existenz von [ReNCl4-nFn]- (n = 1-3) Nitridorhenat(VI)-Gemischt- ligandkomplexen -Eine EPR-Untersuchung / EPR Evidence of [ReNCl4-n FnJ– (n = 1-3) Nitridorhenate(VI) Mixed-Ligand Complexes
Authors: Voigt Andreas , Abram Ulrich , Kirmse Reinhard
Published: February 2015

The formation of mixed-ligand complexes of the type [ReVlNCl4-nFn]- (n = 1 -3) during the reaction of [ReVINCl4]- with [n-(C4H9)4N]F, KF, and HF is reported. Evidence of the individual mixed-ligand compounds is given by their EPR spectral data. In frozen solutions a specific dependence of the EPR data on the composition of the coordination sphere could be detected. This is shown (i) by a nearly linear dependence of gII and AII Re on the Cl/F-content of the [ReVINCl4-nFn]- unit (additivity rules) and (ii) by well-resolved 19F hyperfine splittings.
Synthesis and Crystal Structure of N-[(15,4R)-2-Oxo-pinanyl]-β-alanine Methylester
Authors: Albert Barbara , Jansen Martin , Jakobi Jörg , Steckhan Eberhard
Published: February 2015

The title compound, N-[(lS,4R)-2-oxo-pinanyl]-β-alanine methylester, is an important starting material for the electrochemical preparation of chiral amidoalkylation reagents in the synthesis of chiral β-substituted β-amino acid derivatives. The investigation of its crystal structure reveals an arrangement of the carbonyl group and the amine function, which is influenced by a hydrogen bonding interaction. This conformation makes the molecule especially appropriate for further synthetical modification