bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Infrared and X-Ray Studies of Diphenyltellurium(IV) Nitrosocarbamylcyanmethanides. X-Ray Evidence for Stability of a Tritelluroxane Fragment -Ph2Te-O-Ph2Te-O-Ph2Te-
Authors: Domasevitch Konstantin V. , Skopenko Victor V. , Rusanov Eduard B. 
Published: February 2015

Abstract
Diphenyltellurium(IV) derivatives of the types Ph2Te{ACO}2 (1), Ph4Te2O{ACO}2 (2) and Ph6Te3O2{ACO} (3) (ACO = nitrosocarbamylcyanmethanide -ONC(CN)C(O)NH2) have been prepared. The IR spectroscopic data reveal that the ambidentate ligands are coordinated to the tellurium(IV) atom in a monodentate manner via the nitroso oxygen atom. The crystal and molecular structure of 3 has been determined from X-ray diffraction data (triclinic, space group P1̅ with a = 12.382(2), 6=13.100(2), c = 14.944(3) Å, a = 87.74( 1), β = 85.04(2), 7 = 66.29( 1)°, V = 2211.0 A , Z = 2, R = 0.040). The structure is made up of unsymmetric molecules, in which the tellurium atoms are linked by oxo bridges to form chains Te-O-Te-O-Te (d(Te-O) ca. 1.94-2.09 A). The Te-0 (nitroso group) bond lengths are in the range 2.33 - 2.36 Å
Zur Reaktivität des Germaethens Me2Ge=C(SiMe3)2: Mechanistische Aspekte der Diels-Aider- und En-Reaktionen [1] / On the Reactivity of Germaethene Me2Ge=C (SiMe3)2: Mechanistic Aspects of Diels Alder and Ene Reactions [1]
Authors: Wiberg Nils , Wagner Susanne 
Published: February 2015

Abstract
Diels-Alder and ene reactions of germaethene Me2Ge=C(SiMe3)2 (2) with butadienes

respectively, take place regioselectively, as well as stereoselectively. They are accelerated by an increasing tendency of substituents in butadiene or propene to donate electrons (e.g. 2-methylbutadiene > butadiene; 2-methylpropene > propene), and retarded by an increasing bulkyness of substituents in 1,4- or 1,3-positions (e.g. 1-methylbutadiene > 2-methylbutadiene; 1-vinylpropene > propene). It is concluded from these studies that Diels-Alder and ene reactions of 2 occur - like those of Me2Si=C(SiMe3)2 (1) or of ethenes >C=C< - in a concerted way and are HOMOdiene-LUMOdienophile and HOMOene-LUMOenophile controlled. Thus 2 and 1 behave as carbon analogues. With regard to a specific diene or ene (e.g. anthracene; toluene), 2 is the better dienophile or enophile than 1 or ethenes. With a fixed diene/ene mixture (e.g. butadiene/propene), 2 acts as the better dienophile, while 1 is the better enophile. These results can be explained by the π/π*- energy difference and the double bond polarity decreasing in the direction 1 > 2. Only cis-piperylene gives a [2+2] cycloadduct with 2. besides two [4+2] cycloadducts, and an ene reaction product
Eine unerwartete Synthese des Triphenyphosphazenium-chlorids, [(C6H5)3PNH2]+CI– und eine Neubestimmung seiner Kristallstruktur / An Unaspected Synthesis of Triphenylphosphazenium Chloride, [(C6H5)3PNH2]+Cl– , and a Redeterm ination of its Crystal Structure
Authors: Vogt H. , Fischer A. , Jones P. G. 
Published: February 2015

Abstract
Triphenylphosphazenium chloride has been prepared by the reaction of triphenylphosphine with trimethylsilylazide in impure, wet dichloromethane. Yields are improved as stoichiometric quantities of water are added. Colourless crystals are obtained by recrystallization from the same solvent. The crystals are triclinic, space group P1̅, Z=2, a = 894,6(3), b - 979,8(3), c = 1142,9(4) pm, α = 107,27(3), β = 93,70(3), y = 92,97(3)°. In the solid state the compound exists as [(C6H5)3PNH2]+ cations, and Cl- anions. Dimeric units are formed by H-bonding. The crystal structure contains one molecule CH2Cl2 per one molecule (C6H5)3PNH2Cl. The cation has a slightly irregular tetrahedral geometry around the P-atom with a relatively short P-N bond
Preparation of an Aminoxyl Analog of the Anticancer Agent Miltefosine
Authors: Sosnovsky George , Lukszo Jan , Brasch Robert C. 
Published: February 2015

Abstract
The synthesis and a few properties of hexadecyl 2-[N,N-dimethyl-N-(2,2,6.6-tetramethyll- oxyl-piperidin-4-yl)ammonio] ethyl phosphate are described. This compound is a spin labeled analog of the antineoplastic drug hexadecylphosphocholine (Miltefosine)
Triterpene Glycosides from Polygala klotzschii
Authors: Krebs Hans Ch. , Sollinger Petra 
Published: February 2015

Abstract
Polygala klotzschii is a toxic plant growing in Brazil. From the methanolic extract of its leaves, two triterpene glycosides could be isolated. Their structures have been determined by spectroscopic means as well as through degradation reactions and by preparing the alditolacetates. The glycosides were identified as 28-0-[β-D-glucofuranosyl(1-2)-β-D-xylopyranosyl(1-4)-α-L-rhamnopyranosyl(1-4)-[α-D-xylopyranosyl(1-3)]-β-D-xylopyranosyl]-3-0-β-D-glucopyranosyl- medicagenate (1) and 28-0-[α-L-rhamnopyranosyl( 1 -4)-a-L-rhamnopyranosyl( 1 -4)-[/3-Dxylofuranosyl( 1-2)-β-D-xylopyranosyl( l-3)]-β-D-xylopyranosyl]-3-0-β-D-glucopyranosyl- 16α-hydroxymedicagenate (2) respectively
Synthese und Redoxverhalten schwefelsubstituierter Naphthochinone-1,4 / Synthesis and Redox Behaviour of Sulfur Substituted Naphthoquinones-1,4
Authors: Knieß Torsten , Mayer Roland 
Published: February 2015

Abstract
Chloro substituted naphthoquinones-1,4 1 react with di-Na-4,5-dithio-1,3-dithiol-2-thiones 2 and other dithiolates to give new sulfur containing heterocyclic quinones 3 and 4 as possible preliminary states to synthesize tetrathiafulvalenes. The reaction of 1 with di-Li-2,2- bis(methylthio)-1,1-ethylendithiol 8 yields the appropriate bis-(methylthio)methylen substituted naphthoquinones 9. The redox behaviour of the new compounds was investigated by cyclic voltammetry
Supram olekulare chloridverbrückte Metall(II)chlorid-Diazin-Komplexe: Kristallstrukturen von [Cd(pyrazin)Cl2], [Zn(pyrazin)Cl2] und [Zn(pyrimidin)C l2] / Supram olecular Chloride Bridged Metal(II) Dichloride Diazine Complexes: Crystal Structures of [Cd(pyrazine)Cl2], [Zn(pyrazine)Cl2], and [Zn(pyrimidine)Cl2]
Authors: Pickardt Joachim , Staub Benedikt 
Published: February 2015

Single crystals of [Cd(pyrazine)Cl2],[Zn(pyrazine)Cl2] and [Zn(pyrimidine)Cl2] were obtained by a diffusion technique from aqueous solutions of the metal dichlorides and solutions of the respective diazine.
The structures consist of “supramolecular” networks of-M-Cl-M - and -M-diazine-M-chains.
Synthese und Kristallstruktur von Ba(HSO4)2(H2SO4)3 und Sr(HSO4)2(H2SO4) / Synthesis and Structure of Ba (HSO4)2(H2SO4)3 and Sr(HSO4)2(H2SO4)
Authors: Werner C. , Kemnitza E. , Worzalab H. , Trojanov S. 
Published: February 2015

From the binary systems M2SO4/H2SO4 (M = Ba. Sr), two new hydrogen sulfates, (Ba(HSO4)2(H2SO4)3 and Sr(HSO4)2(H2SO4), have been synthesized and structurally characterized.
Ba(HSO4)2(H2SO4)3 crystallizes in the orthorhombic space group P21212, with unit cell parameters a = 4.680(1), b = 11.267(2), c = 29.188(6)A, Z = 4. BaO9 trigonal prismatic polyhedra with Ba-O distances of 2.68 - 3.02 Å from nine different SO4 tetrahedra are connected via common bases and build “isolated” columns consisting of O-S-O bridged double chains along the x-axis. HSO4 and H2SO4 tetrahedra are linked via hydrogen bonds to form columns. Sr(HSO4)2(HTSO4) crystallizes in the triclinic space group P1̄ with unit cell parameters a = 5.971(1), b = 8.468(2), c = 10.226(2)Å, α = 81.71(3), β = 83.30(3), γ = 70.69(3)°, Z = 2. Sr is coordinated by nine oxygen atoms from seven different SO4 tetrahedra with Sr-O distances of 2.47 - 2.84 Å. The SrO9 polyhedra build layers consisting of O-S-O bridged chains. Three crystallographically different SO4 tetrahedra are linked via hydrogen bonds to form a kind of flattened cylinder along the x-axis.
Untersuchungen an Polyhalogeniden, XXV [1]. Triiodide von Pyridinkomplexen des zweiwertigen Palladiums: Dipyridinpalladiumhexaiodid Pd(py)2I6 und zwei Formen des Tetrapyridinpalladiumhexaiodids Pd(py)4I6 / Studies on Polyhalides, XXV [1]. Triiodides of Pyridine Complexes of Divalent Palladium: Di(pyridine)palladium Hexaiodide Pd(py)2I6 and Two Forms of Tetra(pyridine)palladium Hexaiodide Pd(py)4I6
Authors: Tebbe Karl-Friedrich , Gräfe-Kavoosian Arista , Freckmann Bernhard 
Published: February 2015

Two forms of the new compound Pd(py)4I6 have been prepared by the reaction of stoichiome­tric amounts of PdCl2, C5H5N, KI and I2 in water. One modification crystallizes triclinically in space group Ρ1̄ with a = 907.7(3), b = 960.5(7), c = 992.0(4) pm, α = 117.31 (4), β = 103.35(3), γ = 86.01(5)° and Z = 1, the other orthorhombically in space group Pnnm with a = 891.6(4), b = 1047.6(4), c = 1659.1(5) pm and Z = 2. Both structures may be described as layerlike packings of I3
- anions and [Pd(py)4]2+ cations. Differences arise from the orientations of the anions and cations within these layers.
The new compond Pd(py)2l6 has been prepared by recrystallisation of Pd(py)4I6 from chlo­roform. It crystallizes in the monoclinic space group I2/a with a = 1801.1(4), b = 584.0(1), c = 2220.5(6) pm, β = 115.78(2)° and Z = 2. The structure is built up from quasi square planar complexes [Pd(py)2l2] and iodine molecules I2 linked together to give alternating screw- and zigzag-shaped chains ^[I_-I2] along [1 0 01 forming nets of type (10, 3) including the Pd2+ ions. The structure may also be described as a layerlike packing of the anionic chains 1
∞[I- · I2] and linear complex cations [Pd(py)2]2+ parallel [0 1 1].
Neue Synthesewege zu neutralen gemischtsubstituierten Eisen-Schwefel-Clustern / Novel Synthetic Pathways to Neutral Mixed-Ligand Iron-Sulfur Clusters
Authors: Harmjanz M. , Junghans C. , Opitz U.-A. , Bahlmann B. , Pohl S. 
Published: February 2015

The reaction of [Fe(NiSiMe3)2)2] with thiols RSH, elemental sulfur, and neutral ligands L (with sulfur donor atoms, e. g. thiourea derivatives) gives [Fe4S4(SR)2L2] clusters in high yields. The structure of [Fe4S4(2.4.6-(C3H7)3C6H2-S)2(dpdmi)2] (dpdmi: diisopropyldimethyl- imidazolthion) was determined by X-ray crystallography.
When [Fe4S4I4]2- is reacted with a large excess of PMePh2 or PMe2Ph [F6S6I2(PMePh2)4] and [Fe6S6l2(PMe2Ph)4]. respectively, are obtained in nearly quantitative yield. Basket-like structures of the [Fe6S6]2+ cores were detected by X-ray structure analysis. While [Fe4S4(SR)4]2- clusters do not react with phosphanes at ambient temperature 2:2 functional­ized species like [Fe4S4(SR)2(tmtu)2] lead to basket-type clusters [Fe6S6(SR)2(PR3)4].
Phosphonio-substituierte Tetrahydro-1,3-diphosphinine und Tetrahydro-1,2,6-azadiphospliinine / Phosphonio-Substituted Tetrahydro-1,3-diphosphinines and Tetrahydro-1,2,6-azaphosphinines
Authors: Jochem Georg , Schmidt Martin , Nöth Heinrich , Schmidpeter Alfred 
Published: February 2015

The bis(triphenylphosphonio)propenide cation 1 provides two reactive CH sites in 1,3- position and can be condensed with the bis(dichlorophosphanyl)methylene triphenylphosphorane 2 or the bis(dichlorophosphanyl)aniline 3 to form cationic six-membered rings: A tetrahydro-1,3-diphosphinine (4) with three phosphonio or phosphoranediyl substituents in 2,4,6-position and a tetrahydro-1,2,6-azadiphosphinine (5) carrying two such substituents in 3,5-position. The bromide of the latter was used for an X-ray structure analysis.
The PIII ring members of the cations 4 and 5 can be oxidized in two steps by elemental sulfur to give the monothioxo and dithioxo derivatives 6. 7 and 8, 9. respectively. A crystal of the mixed chloride/bromide of 8 was used for another X-ray structure analysis.
Synthese und Charakterisierung des Fulleren-Kokristallisats C60*SiH(C6H5)3/Synthesis and Characterisation of the Fullerene Co-Crystal C60*SiH(C6H5)3
Authors: Waidmann G. , Jansen M. 
Published: February 2015

Abstract
A new fullerene co-crystal C60*SiH(C6H5)3 has been synthesized by crystallisation from a melt of SiH(C6H5)3 and C60 in sealed duran tubes at 80°C. X-ray investigations led to triclinic symmetry, space group P1̄, a = 10.086(1), b = 14.431(2), c = 14.911(2) Å, α = 79.13(1), β = 74.943(9), γ = 88.33(1)°, V = 2058.0(4) Å3, Z = 2. The crystal structure consists of isolated fullerene and silane molecules. At -80°C, C60 is still rotationally disordered. Temperature dependent Guinier powder diagrams do not show any phase transformation between 25 and -165°C. The compound is stable in air.
Enantioselektive Katalyse, XVIII Der Einfluß nicht koordinierter Stereozentren auf die enantioselektive Hydrierung/Enantioselective Catalysis, XVIII The Influence of Non-Coordinated Stereocenters on the Enantioselective Hydrogenation
Authors: Nagel Ulrich , Roller Christoph 
Published: February 2015

Abstract
3,4-Bis{[2-(methyl-phenyl-oxophosphanyl)-ethyl]phenyl-phosphanyl}pyrrolidines have be­en synthesized by Michael Addition from the corresponding methyl-phenyl-vinyl-phosphane oxides and 3,4-bis(phenylphosphino)pyrrolidines. For purification of the ligands palladium complexes were used and with the enantiomerically pure ligands Rh complexes have been pre­pared. The catalyst has 6 stereogenic centers. In the hydrogenation of Z-α-acetamidocinnamic acid all six stereogenic centers have an influence on the enantioselectivity. The influence is strongest from the C stereocenters of the pyrrolidine ring. Less important are the stereogenic centers on the coordinated P atoms. The influence of the stereocenters on the non-coordinated P = O groups is the least, but it is not negligible. The ee values obtained with the ligands containing P = O groups are much lower than those obtained with ligands which are substituted only with aryl groups. Ketones are hydrogenated with only low ee’s.
Darstellung, Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von [Os(acac)3]/ Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of [Os(acac)3]
Authors: Dallmann K. , Preetz W. 
Published: February 2015

Abstract
In the reaction of K2[OsCl6] with boiling water/acetylacetone (1:1) a mixture of different chloro-acetylacetonato complexes is formed, from which [Os(acac)3] can be isolated by column chromatography with dichloromethane on silica gel. The crystal structure of [Os(acac)3] (mo­noclinic, space group P21/c,a = 13.968(5), b = 7.517(5), c = 16.455(5) Å ,β = 98.939(5)°, Z = 4) has been determined by single crystal X-ray diffraction analysis. High resolution IR and Raman spectra were measured at low temperature (10K). Based on the molecular parameters of the X-ray structure determination a normal coordinate analysis has been performed and the normal modes of vibration have been assigned. With a set of 32 force constants, taking into account the intraligand vibrations, a good agreement between observed and calculated frequencies has been achieved. The valence force constants are fd(OsO) = 3.19 and fd(OC) = 6.74 mdyn/Å.
Synthese und Kristallstruktur von [H2NMe2]+[(Me2NH)2 TiCl4]-/Synthesis and Crystal Structure of [H2NMe2]+[(Me2NH)2TiCl4]-
Authors: Bettenhausen Regina , Milius Wolfgang , Schnick Wolfgang 
Published: February 2015

Abstract
The title compound has been synthesized as a green solid by the reaction of MeCl2 SiNHSiMe3 and Ti(NMe2)4 in CH2Cl2. The crystal structure was determined by single crystal X-ray methods at room temperature (C2/c, a = 1825,7(4), b = 909,9(2), c = 1116,1(2) pm, β = 125,09(3)°, Z = 4,R1= 0,047, wR2 = 0,147) to be an ionic salt [H2NMe2]+[(Me2NH)2TiCl4]- . The central titanium(III) atom of the anion is bound to four Cl atoms and weakly coordinated by two Me2NH ligands.
Enantioselective Catalysis, XVII [1]. Enantioselective Catalytic Hydrogenation of Unfunctionalized Ketones
Authors: Nagel Ulrich , Roller Christoph 
Published: February 2015

Abstract
Three diastereomeric rhodium bisphosphane complexes have been applied to asymmetric hydrogenation of unfunctionalized, non-chelating aliphatic and aromatic ketones. The ee values of the catalysis products differ considerably for the diastereomerical catalysts. 70% ee were obtained in hydrogenating butyrophenone, and 83.7% ee for pinacoline. The results depend strongly on the solvent used.
Zur Kristallchemie der Silber-Mangan-Oxovanadate Ag2BaMnV2O8 und (AgCa2)Mn2(VO4)3 / On the Crystal Chemistry of the Silver Manganese Oxovanadates Ag2BaMnV2O8 and (AgCa2)Mn2(VO4)3
Authors: Rettich R. , Müller-Buschbaum Hk. 
Published: February 2015

Abstract
Single crystals of Ag2BaMnV2O8 (I) and (AgCa2)Mn2(VO4)3 (II) have been prepared by reactions of metallic silver and mixtures of MnCO3H2O , V2O5 and L/II; BaCO3/CaCO3. Crystal structure investigations by X-ray methods led to I: trigonal symmetry, C1
3i-P3̅, a = 5.5693(4), c = 7.2706(6) A, Z = 1 and II: cubic symmetry, O10
h-Ia3̅d, a = 12.6084(9) Å, Z = 8 . Despite of different symmetry compound I is strongly related to the monoclinic compounds Ag2SrCuV2O8 and Na2BaCuV2O8, respectively. II belongs to the garnets. Compound I is characterized by [BaOg] nets with incorporated V5+ and Ag+ ions. The [BaOg] nets are connected by Mn2+ ions. A discussion of structural details of I with respect to Ag2SrMnV2O8, Na2BaCuV2O8 and the two modifications of K3Na(CrO4 )2 is given.
Zur Synthese fluororganischer O-(Trimethylsilyl)-cyanhydrine / Synthesis of Fluoroorganic O-(Trimethylsilyl)Cyanhydrines
Authors: Sander Michael , Sundermeyer Wolfgang 
Published: February 2015

Abstract
Fluororganic and/or sterically hindered cyanohydrines are useful synthetic reagents, not readily available directly from e.g. aldehydes or ketones and hydrogen cyanide. By using trimethylsilyl cyanide (TMSCN), the obtained O-Silyl-cyanohydrines can be applied successfully for the same purpose. Selected examples of the type R1R2C-CN(OSiMe3) 1 -12 are presented which prove the extensive applicability of this reaction [R = (fluoro)alkyl, (fluoro)aryl, anthryl, cyclopropyl, CCl3, CBr3 etc.]. Malodinitrile derivatives RC(CN)2OSiMe3 14 were obtained from carboxylic acid chlorides, α-, β- and 7 -Diketones react with formation of the corresponding linear or cyclic doubly substituted O-Silylcyanohydrines 16, 17, 21, 22. The enol-form of hexafluoroacetylacetone reacts with silylation to give the E-isomer of the silylenol ether 18, the carbonyl group of which forms the O-Silylcyanohydrine 19. With Me2Si(CN)2 both reaction steps occur intramolecular, yielding a 2,6-dioxa-l-sila-3-cyclohexene 20.
Supersilylverbindungen Der Borgruppenelemente, IV [1]. Supersilylelementhalogenide tBu3SIEX2 Und (tBu3Si)2Ex Mit E = Al, Ga, In: Synthesen, Eigenschaften, Strukturen [2] / Supersilylated Compounds of the Thirteenth Group, IV [I]. Supersilylelement Halides tBu3SIEX2 And (tBu3Si)2Ex with E = Al, Ga, In: Syntheses, Properties, Structures [2]
Authors: Wiberg Nils , Amelunxen Kerstin , Lemer Hans-Wolfram , Nöth Heinrich , Knizek Jörg , Krossing Ingo 
Published: February 2015

Abstract
Water and oxygen sensitive compounds (tBu3SiEX2)2, tBu3SiEX2 Do and (tBu3Si)2EX (E = AI, Ga, In; X = (F), Cl, Br; Do = OR2, NR3) have been synthezised by reaction of EX3 with tBu3SiNa in the absence or presence of donors. In addition, (tBu3Si)AlBr2, (tBu3Si)2InF and tBu3SiInBr2 were prepared by reaction of AlBr3 with (tBu3Sij2Zn or of (tBu3Si)2In- In(Si/Bu3)2 with AgF2 and HBr, respectively. The adduct [tBu3SiAlBr2 · AlBr3 ·1/2MgBr2]2 is formed from AlBr3 and (tBu3Si)2Mg(THF)2. Thermal decomposition of the compounds in solution or in the gas phase leads to the formation of tBu3SiEX2 (from the dimers or the donor adducts) and of tBu3SiX. The Lewis acidity of tBu3SiEX2 against donors increases in the direction Do = Et2O < THF < NEtMe2. Dehalogenation of (tBu3Si)2ECl with tBu3SiNa(THF)2 in pentane at room temperature leads to clusters (tBu3Si)4Al2, (tBu3Si)3Ga2
•, (tBu3Si)4In2 and (tBu3Si)3Ga2Na(THF)3, reduction of tBu3SiGaCl2 with Na or K in heptane at 100°C to the tetrahedran (tBu3Si)4Ga4. The structures of (tBu3SiGaCl2)2, (tBu3Si)2GaCl, and [tBu3SiAlBr2 AlBr3 ·1/2MgBr2]2 have been determined by X-ray structure analysis.
Untersuchungen zum chemischen Transport von YX3 mit AlX3 und zur Existenz von gasförmigen und festen Komplexen YAl3 X12 (X = Br, I) / Investigations on the Chemical Transport Reaction of YX3 with AlX3 and on the Existence of Gaseous and Solid Complexes YAl3 X12 (X = Br, I) H
Authors: Oppermann H. , Herrera S. , Huong Dao Quoc 
Published: February 2015

Abstract
The dominant gaseous complexes YAl3Br12 and YAl3I12 were generated in the chemical trans­port reactions of YBr3 with AlBr3 and YI3 with AlI3. The enthalpy of formation
ΔH0
B(YAl3Br12,g,298) = -484,5 ± 6 kcal/mol
and the standard entropy
S°(YA13B12,g,298) = 290,0 ± 7,5 cal/K·mol
have been calculated. It follows from total pressure measurements of mixtures of YBr3,s with AlBr3,1 and YI3,s with AlI3,1 respectively, that complexes YAl3Br12,s and YAl3I12,s do not exist up to the boiling points of the aluminium trihalides.
Synthesis and Mesomorphic Properties of Polymethylene-α,ω–bis [2-thio- 5-(4',4"n-alcoxybenzoyIoxy)phenyl]-1,3,4-oxadiazole
Authors: Aguilera C. , Parra M. , Fuentes G. 
Published: February 2015

Abstract
Three homologous series of polymethylene-α,ω-bis[2-thio-5(4′,4″n-alkoxybenzoyloxy)- phenyl]-1,3,4-oxadiazole (series 5 a, b, c), are reported.The compounds have identical mesogenic units at both ends of a spacer (i.e. they are twins). These twins possess a spacer of 6, 8 and 10 carbon atoms joined directly to the oxadiazole ring through sulphur atoms. The lateral alkylic chains vary between 6 and 10 carbon atoms.The presence of enantiotropic and monotropic nematic phase is related to the length of the spacer group. The influence of molecular structure on the mesomorphic properties has been studied. Mesomorphic properties and phase transitions have been determined using polarizing hot-stage microscopy and differential scanning calorimetry.
Syntheses and Structures of Cyclopentadienyl Arsenic (III) Compounds Part IIIa: Tetraisopropylcyclopentadienyl Arsenic (III) Dibromide and Tetraisopropyl- cyclopentadienyl Arsenic (III) Diiodide (TipCpAsBr2, TipCpAsI2)
Authors: Megges Klaus , Avtomonov Evgeni V. , Becker Ralf , Lorberth Jörg 
Published: February 2015

Abstract
1,2,3,4-Tetraisopropylcyclopenta-2,4-dien-1-yl arsenic (III) dihalides, viz. TipCpAsX2 (1 X = Br, 2 X = I), have been prepared by direct metathesis reaction between the corresponding arsenic (III) trihalides with one equivalent of TipCpK at low temperature in good yields. Alternatively, 2 has been prepared via halogen exchange reaction between TipCpAsCl2 (3) and KI. New compounds have been characterised by spectroscopic m ethods ( 1H, 13C NMR. EI-MS) and elemental analyses. The crystal structures of 1 and 2 have been determined by X-ray diffraction methods. The AsX2-moiety in 1 and 2 occupies an allylic position neighbouring to an isopropyl substituent. The arsenic fragment is o-bound to the cyclopentadienyl ligand, indicating remarkable π-interactions with the diene part of the cyclopentadienyl ring.
Die Tieftemperaturkristallstruktur von Trimethylsilanol / The Low Temperature Crystal Structure of Trimethylsilanol
Authors: Minkwitz Rolf , Schneider Stefan 
Published: February 2015

Abstract
A preparation of trimethylsilanol by hydrolysis of bis(trimethylsilyl)carbonate in diethylether at -20°C is reported. At -80°C, the crystals are monoclinic, space group P21/c, Z = 12 with cell dimensions a = 996.0(2) pm, b = 1730.2(3) pm, c = 1122.9(2) pm, β= 96,61(3)°. There are three independent Me3SiOH units with a slightly distorted tetrahedral C3SiO core structure.
An Aluminium-Oxide-Isopropoxide Cluster with Peripheral Ammonia Ligands
Authors: Tripathi Upendra M , Schier Annette , Schmidbaur Hubert 
Published: February 2015

Abstract
The reaction of toluene solutions of aluminium isopropoxide with ammonia gas, without exclusion of moisture, affords high yields of a decanuclear aluminium-oxide-isopropoxide-ammonia cluster of the composition [Al10O6(OiPr)18(NH3)8]. The compact centrosymmetric cluster units feature tetra-, penta- and hexa-coordinate aluminium atoms, tri- and tetra-coordinate interstitial oxygen atoms, and bridging and terminal isopropoxide groups. The ammonia molecules occupy peripheral positions at two types of aluminium atoms