bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxa-azonia-boratacyclopentanes by Insertion of Dimethylaminobis(trifluoromethyl)borane into Epoxides
Authors: Bürger Hans , Hagen Thomas , Pawelke Gottfried
Published: March 2015

Dimethylaminobis(trifluoromethyl)borane, (CF3)2BNMe2 (A), reacts with epoxides of the general formula

to yield five-membered heterocycles

(CF3)2

, R = Me (1), CH,F (2), CF3 (3), Et (4), Bz (5). With R = Ph a 1:2 mixture of the isomers (CF3)2

O (6a) and (CF3)2

(6b) is obtained. To the contrary,

and A form the borane-dimethylamine adduct (H2C=CMe—CH2-O)(CF3)2B • NHMe2 (7). The compounds have been characterized by elemental analyses, multinuclear NMR, IR and mass spectra.
Zinn(IV)-Verbindungen mit Ferrocenylchalkogenat- und Ferrocenylendichalkogenat-Liganden. Synthese und Multikern-NMR-Spektroskopie / Tin(IV) Compounds Containing Ferrocenyl Chalcogenate and Ferrocenylene Dichalcogenate Ligands. Synthesis and Multinuclear NMR Spectroscopy
Authors: Herberhold Max , Hübner Michaela , Wrackmeyer Bernd
Published: March 2015

A series of tin(IV) compounds containing ferrocenyl chalcogenate (FcE) and ferrocenylene dichalcogenate (fcE2) ligands (E = S, Se, Te) has been synthesized for a systematic study of the NMR spectra with particular emphasis on 13C, 119Sn, 77Se and 125Te NMR. All compounds are formally derived from tetramethylstannane, SnMe4, by stepwise replacement of methyl by either FcE or fcE2 ligands. Starting from lithioferrocene the products are tetrasubstituted stannanes Me4-nSn(EFc)n (n = 1 and 2, E = S, Se, Te; n = 3 and 4, E = S, Se). Starting from 1,1′dilithioferrocene, the products are 1,1′-disubstituted ferrocenes such as fc(E-SnMe3)2 (E = S, Se, Te), although 1,3-dichalcogena[3]ferrocenophane rings are formed whenever possible to give [3]ferrocenophanes fcE2SnMe2 (E = S, Se, Te) and fc[E-Sn(Me)E2fc]2 (E = S, Se) or tin spiro compounds Sn(E2fc)2 (E = S, Se, Te). Whereas all (8) possible sulfur-containing and all (8) selenium-containing products were accessible, some of the tellurium-rich compounds could not be isolated due to preferred formation of either Fc2Te2 or fcTe3.

All compounds were characterized on the basis of their 1H, 13C, 119Sn and, if possible, 77Se and 125Te solution NMR spectra. In many cases, coupling constants such as 2J(119Sn1H), nJ(119Sn13C) (n = 1,2,3), 1J(119Sn77Se) and 1J(125Τe119Sn), 1J(77Se13C) and 1J(125Te13C) could be determined. The δ119Sn chemical shifts of analogous phenyl and ferrocenyl compounds, Me4-nSn(EPh) and Me4-nSn(EFc)n (n = 0-4, E = S, Se, Te), are discussed, and for a microcrystalline sample of tetrakis(ferrocenylselenolato)stannane, Sn(SeFc)4, the 119Sn and 77Se CP/MAS NMR spectra are reported and compared with the solution spectra.
Hydrogen Bonding in Crystals of an Ammonium Catecholate NH4[C6H4(OH)2][C6H4(OH)O] · 0.5 H2O
Authors: Kumberger Otto , Riede Jürgen , Schmidbaur Hubert
Published: March 2015

A discrete ammonium catecholate hydrate of the composition

NH4[C6H4(OH)2][C6H4(OH)O] · 0.5 H2O has been isolated and characterized by a single-crystal X-ray structure analysis. The crystals are monoclinic, space group C 2/c (No. 15), Z = 8, a = 24.613(3), b = 8.706(1), c = 11.890(2) Å, β = 110.56(1)°. The crystal lattice features a network of hydrogen bonds, which clearly contribute significantly to the overall stability of the lattice. The water molecule is engaged as a donor and an acceptor in as many as four hydrogen bonds. Surprisingly, the crystalline compound is air-stable, while anhydrous ammonium catecholate, as obtained by dissolving catechol in dry liquid ammonia, is quickly oxidized in air.
Preparation and Crystal Structure of Zinc Bis[orotate(1–)] Octahydrate
Authors: Kumberger Otto , Riede Jürgen , Schmidbaur Hubert
Published: March 2015

A discrete zinc bis[orotate(1—)] complex of the composition Zn(OrH)2·8 H2O has been isolated and characterized by a single-crystal X-ray structure analysis. The crystals are monoclinic, space group P21/c (No. 14), Z = 2, a = 10.884(2), b = 12.896(1), c = 6.954(1) Å, β = 98.27(1)°. The crystal lattice features hexaquo complexes of zinc, the Zn(H2O)6
2+ cations being associated with two hydrated OrH- ions only through hydrogen bonds. The results are relevant for applications of zinc orotates in medical treatment.
2-Selenoimidazoline / 2-Selenoimidazolines
Authors: Kuhn Norbert , Henkel Gerald , Kratz Thomas
Published: March 2015

The 2-selenoimidazolines 5 are obtained from the reaction of the imidazol-2-ylidenes 4 with selenium in very good yields. The ylidic nature of the carbon selenium bond (2) is revealed both by NMR and by X-ray analysis. On comparison with the corresponding tellurium compounds 3, reduction of the carbon chalcogen bond order in 5 is suggested.
Clathrates with Three-Dimensional Host Structures of Hydrogen-Bonded Pentaborate [B5O6(OH)4]- Ions: Pentaborates with the Cations NMe4
+, NEt4
+, NPhMe3
+ and pipH+ (pipH+ = Piperidinium)
Authors: Wiebcke Michael , Freyhardt Clemens C. , Felsche Jürgen , Engelhardt Günter
Published: March 2015

X-ray structure analyses of crystalline [NMe4][B5O6(OH)4] · nH2O with n ≈ 0.25-0.50 (1), [NEt4][B5O6(OH)4] (2), [NPhMe3][B5O6(OH)4] (3), and [pipH][B5O6(OH)4] (4) reveal that these materials are novel clathrates with closely related three-dimensional host structures built up of hydrogen-bonded oligomeric pentaborate [B5O6(OH)4]- ions. The organic cations and water molecules (in 1) occupy as guest species large straight channel-like voids of nearly rectangular cross-section. Compound 1 crystallizes monoclinically with space group P2,/c (Z = 4); the compounds 2,3 and 4, which possess the same host-structure topology, crystallize triclinically with space group P1̄ (Z = 2). 11B-MAS NMR spectra allow the detection of small angular distortions in the pentaborate anions caused by the specific hydrogen bonding in the host frameworks. Upon heating the compounds on a thermobalance in a dynamic inert gas atmosphere dehydration occurs at temperatures of 563 K (1), 543 K (2), 558 K (3) and 523 K (4) before degradation of the organic cations starts at temperatures of 633 K (1), 623 K (2), 623 K (3) and 613 K (4).
Cl NQR Spectra of Some New Iridium Chlorochalcogenide Complexes
Authors: Fokina Z. A. , Pekhnyo V. I. , Volkov S. V. , Lapko V. F. , Bryukhova Y. V. , Kuznetsov S. I.
Published: March 2015

The 35C1 NQR spectra of the chlorochalcogenide complexes of iridium (SCl3)2 [IrCl6] 1, (TeCl3)2 [IrCl6] 2, (SeCl3) [IrCl6] 3, [IrCl3(SCl2)2]2 4, (SCl3) [IrCl4(SCl2)2] 5 and [IrCl3(SeCl2)2]2 6 have been studied. The spectra were recorded by pulse spectrometry. They consist of two mul tiplets, widely separated in frequency. The high-frequency multiplet belongs to the chlorine atoms bonded to sulfur, selenium and tellurium, respectively, in the ligand. A high-frequency shift is observed, which is typical for the coordination of the molecules ACl2(A=S, Se) and ACl4(A=S, Se, Te). The low frequencies in the multiplets of 4 and 6 are attributed to additional bonds formed between chalcogen atom and chlorine in the coordination environment of iridium.

In the spectral region 18-24 MHz lie the NQR frequencies of 35Cl bonded to iridium. For 2 the frequencies are close to those of [IrCl6]2-, which confirms the Ir oxidation state IV. The unexpectedly high frequencies for IrIII in the case of 4 and 5 are explained by the influence of ACl2 molecules, which are weaker σ-donors than the chloro ligands. This promotes electron density transfer from neighbouring chlorine atoms. The 18 MHz frequency is assigned to the bridge chlorine atoms in dimeric molecule 4. This assignment is confirmed by the positive value of d v/dT = +0,2.
Notizen: Preparation and Characterization of (C6H5CH2CH2NH3)2SnI4 and (C6H5CH2CH2NH3)2SnBr4
Authors: Papavassiliou G. C. , Koutselas J. B. , Lagouvardos D. J.
Published: March 2015

The title compounds were prepared in crystalline form and characterized analytically and spectroscopically.
Notizen: The Crystal Structures of Pyridinium Chloride Revisited: Evidence for Extensive C–H ••• Cl Hydrogen-Bond Interactions
Authors: Aakeröy Christer B. , Seddon Kenneth R.
Published: March 2015

A reinvestigation of the previously determined structures of two polymorphs of pyridinium chloride shows that both polymorphs contain several aromatic C– H-H···Cl hydrogen-bond interactions. These hydrogen bonds, hitherto unrecognized, may play a significant structural role, both in solution and in the solid-state.
Verbindungen mit SiS2-isosteren Anionen ∞
1[AlX4/2
3-] und ∞
1[InP4/2
3-]: Synthesen, Kristallstrukturen und Schwingungsspektren von Na3[AlX2], K2Na[AlX2] und K3[InP2] (X = P, As) / Compounds with SiS2 Isoelectronic Anions ∞
1[AlX4/2
3-] and ∞
1[InP4/2
3-]: Synthesis, Crystal Structures and Vibrational Spectra of Na3[AlX2], K2Na[AlX2] and K3[InP2] (X = P, As)
Authors: Ohse Lothar , Somer Mehmet , Blase Wolfgang , Cordier Gerhard
Published: March 2015

The title compounds were prepared from stoichiometric mixtures of the elements or from alkali metals (Na, K), NaX (KX) and MX (M = Al, In; X = P, As) at 1000 K. The crystal structures (Ibam, No. 72) are characterized by infinite chains of edge sharing tetrahedra ∞
1[MX4/2
3-] (M = Al, In; X = P, As) which are isoelectronic to SiS2.

The vibrational spectra can be interpreted with respect to the symmetry P(2/m 2/c) 42/m–D4h of the isolated polymeric chain ∞
1[MX4/2
3-]. The assignment of the observed frequencies is supported by a normal coordinate analysis using the fragment method.
Impedanzspektroskopische Untersuchungen am Ag – Ge-Zeolithen Ag3HGe7O16·4H2O und seinen Pyrolyseprodukten Ag2Ge4O9 und Ag4Ge9O20 / Impedance Spectra of the Ag– Ge-Zeolite Ag3HGe7O16·4H2O and its Pyrolysis Products Ag2Ge4O9 and Ag4Ge9O20
Authors: Brodersen K. , Schrenk J.
Published: March 2015

The structures of the Ag–Ge-zeolite Ag3HGe7O16·4H2O and its pyrolyse products Ag4Ge9O20 and Ag2Ge4O9 consist of a network of linked (GeO4)-tetraedra and (GeO6)-octahedra. In this network there exist free channels, which can be used as transport paths through the structure by Ag+-ions. Impedance spectroscopic measurements show the loss of weakly bonded water at about 210°C and irreversible structural changes, which finally lead to the pyrolysis products. Lattice vibrations prevent a better Ag+-mobility, so the high expectations concerning the conductance properties could not be fulfilled. In all cases the main part of the resistance could be attributed to the grain boundaries between the crystals.
Die kristallinen Hydrate von Tetramethylammoniumfluorid. Bildung, Struktur, Wasserstoffbrückenbindung [1] / The Crystalline Hydrates of Tetramethylammonium Fluoride. Formation, Structure, Hydrogen Bonding
Authors: Stäben Dieter , Mootz Dietrich
Published: March 2015

The melting diagram of the system Me4NF-H2O in the region 50-100 mol% H2O has been investigated for the first time, using DTA, DSC and temperature-dependent X-ray powder diffraction. Four crystalline hydrates Me4NF·xH2O were found, with x = 1,2.33,4 and 5, which decompose irreversibly above ca. 160°C and melt incongruently at 36°C, congruently at 46°C and again incongruently at 10°C, respectively. The crystal structure of each hydrate, except the already known one of the tetrahydrate, has been determined with MoKa diffractometer data. The monohydrate is rhombohedral with space group R3̄̄m and Z = 6 formula units per unit cell (hexagonal axes), the 2.33-hydrate monoclinic with P21/n and Z = 12, and the pentahydrate tetragonal with I4̄2 m and Z = 2. The hydrogen-bonded H2O/F- structure is an isolated centrosymmetric [F2(H2O)2]2- four-membered ring in the monohydrate, a rather open three-dimensional network in the 2.33-hydrate and a corrugated dense layer of fused fivemembered rings in the pentahydrate.
The Molecular Structures and Conformational Preferences of Simple Molecules Containing Bonds Between a Trivalent Group 15 and a Divalent Group 16 Element: The Molecular Structures of Dimethyl(methylthio)stibane and Dimethyl(methylseleno)stibane, (CH3)2SbECH3 E = S or Se, by Gas Electron Diffraction
Authors: Haaland Arne , Verne Hans Peter , Volden Hans Vidar , Breunig Hans Joachim , Gülec Sabahittin
Published: March 2015

Gas electron diffraction data of (CH3)2SbECH3 E = S or Se, show that the predominant conformer is one where the dihedral angle defined by the E–C bond, the Sb–E bond and the presumed direction of the lone pair at the Sb atom falls in the range –45 to +45°. The Sb–S and Sb–Se bond distances are 241.4(8) and 255.5(3) pm, respectively.
Magnetische Untersuchungen an ACrF4-Verbindungen mit A = K, Rb, Cs 57Fe-Mößbauer-Spektren von CsCrF4 / Magnetic Studies of the Compounds ACrF4 (A = K, Rb, Cs) A Mössbauer Study of 57Fe-Doped CsCrF4
Authors: Kampe O. , Frommen Ch. , Pebler J.
Published: March 2015

From the results of magnetic susceptibility and magnetization measurements of the triple chains ACrF4 (A = K, Rb, Cs), the characteristics of one-dimensional antiferromagnetic chains are found. The exchange parameters J/k are —6.2 K and —12.2 K for KCrF4 and CsCrF4, respectively. Measurements on single crystals of RbCrF4 reveal the exchange and the anisotropy parameters to be J/k = —10.5 K and D/k = 0.4 K. The Mössbauer spectra of 2% 57Fe doped CsCrF4 show marked relaxation. One third of the magnetic chains are frustrated and remain uncorrelated with other magnetic chains.
Thermodynamische Untersuchungen der Systeme Pyridin/CH3SiCl3 und Pyridin/Cl3CCH3 / Thermodynamic Examinations of the Systems Pyridine/CH3SiCl3 and Pyridine/Cl3CCH3
Authors: Zenke Michael W. , Hensen Karl
Published: March 2015

The isobaric melting and boiling diagrams for the systems: pyridine/methyltrichlorosilane and pyridine/1,1,1-trichloroethane are reproduced. The existence of the congruently melting addition compound CH3SiCl3· (Pyridin)2 could be confirmed. Some measurements of the molar volume of mixtures between pyridine and methyltrichlorosilane and pyridine and 1,1,1-trichloroethane, respectively, are reported. For both systems the molar excess volume and for the system pyridine/methyltrichlorosilane the molar excess enthalpie have been calculated as a function of the mole fractions.
The Synthesis and Crystal Structure of N-tert-Butyl-3-(tert-butylimino)-2-nitropropen-1 -amine
Authors: Ostercamp Daryl L. , Preston Lisa M. , Onan Kay D.
Published: March 2015

The unit cell of N-tert-butyl-3-(tert-butylimino)-2-nitropropen-1-amine (4) is monoclinic, space group P21/C, with a = 9.669(4), b = 16.415(6), c = 17.341 (7) Å, and Z = 4. Hydrolysis of 4 leads to (E)-3-(N-tert-butylamino)-2-nitro-2-propenal (5), whose unit cell is monoclinic, space group P21/n, with a = 6.821(1), b = 20.707(6), c = 6.303(1)Å, and Z = 4. Compounds 4 and 5 both possess C2 symmetry in the solid state, their “U-shaped” conjugated cores being essentially planar. In each case this planarity is enforced by an intramolecular hydrogen bond.
[TaTe4]4[PtI6]I2, ein neues quaternäres Tellurid-Iodid mit Kettenstruktur / [TaTe4]4[PtI6]I2, A New Quaternary Telluride-Iodide with Chain Structure
Authors: Tremel Wolfgang , Stork Karl-Ludwig
Published: March 2015

[TaTe4]4[PtI6]I2 was synthesized from the elements at 680°C. Its crystal structure was determined using single crystal methods. The structure of the quasi one-dimensional compound [TaTe4]4[PtI6]I2 (P1̄, Z = 1, a = 16.831(1), b = 17.740(1), c = 19.018(1)Å, α = 93.57°, β = 94.08°, γ = 102.09°) consists of Ta(Te2)2 chains separated by PtI6 groups and I atoms. The formal oxidation state assignment [(Ta5+)(Te2
2-)2]4[(Pt4+)(I-)6](I-)2 indicates that semiconducting properties are to be expected for this material.
Erstmaliger Nachweis von π–π Dimerenbildung bei stabilen 1,4-Dialkylchinoxalinium-Radikalkationen. Struktur, Spektroskopie und Magnetismus / First Evidence for π-π-Dimerization of the Stable 1,4-Dialkylquinoxalinium Radical Cations. Structure, Spectroscopy and Magnetism
Authors: Hausen H.-D. , Kaim Wolfgang , Schulz Andreas , Moscherosch Michael , Jordanov Jeanne
Published: March 2015

Crystal and molecular structure analysis of 1,4-diethylquinoxalinium iodide shows a virtually planar quinoxaline ring with 11 conjugated π-electrons. In contrast to the triiodide of the 1,4,6,7-tetramethyl derivative or to the tetraphenylborate salt of 1,4-diethylquinoxalinium cation radical the iodide exhibits π-π-dimerized radical cations in the solid state with synplanar ethyl groups and a rather small intermolecular distance of about 315 pm between the π-planes of the primarily interacting 1,4-diazine rings. Solid state magnetic measurements between 2 and 300 K show considerably diminished magnetic moments due to partial spin-pairing, and UV/VIS spectroscopic measurements in acetonitrile reflect the π—π-interaction in solution through the appearance of a long-wavelength absorption band.
Reaktive E=C(p–p)π-Systeme, XXXVI [1] Darstellung, Reaktivität und Ligandeneigenschaften des Trifluormethyl-1,3-diphosphans tBu(H)PCF2P(H)CF3 / Reactive E=C(p—p)π Systems, XXXVI [1]. Synthesis, Reactivity and Ligand Properties of the Trifluoromethyl-1,3-diphosphane tBu(H)PCF2P(H)CF3
Authors: Grobe Joseph , Großpietsch Thomas , Le Van Duc , Krebs Bernt , Läge Mechtild
Published: March 2015

Trifluoromethyl-1,3-diphosphane tBu(H)PCF2P(H)CF3 (2) is formed regioselectively in almost quantitative yield by addition of tert-butylphosphane to perfluoro-2-phosphapropene F3CP=CF2 (1) as a 1:1 mixture of two diastereomers 2 a and 2b. 2 reacts with nickel tetracarbonyl to give the binuclear complex [tBu(H)PCF2P(H)CF3Ni(CO)2]2 (3) as the only isolable product. The mixture contains four of the eight possible isomers; one of them (3 a) could be isolated in pure form by crystallization from n-pentane solution. Attempts to generate the phosphaalkene tBu(H)PC(F)=PCF3 or the 1,3-diphosphaallene tBuP=C=PCF3 by HF elimination from 2 with NEt3, HNMe2 or HNEt2 lead to complicated mixtures of products. On the other hand, reaction of 3 a with isopropylamine affords the binuclear complex [(CO)Ni(F3CP=CFP(H)tBu)Ni(CO)2tBu(H)PCFHP(CF3)NHiPr] (4) with both a 16 eand an 18 e-nickel(O) fragment and a side-on coordinated F3CP=CF group. The new compounds were characterized by spectroscopic investigations, 3 a and 4 by an X-ray diffraction study.
Thermostabilität von Vinylmagnesiumchlorid in Tetrahydrofuran / Thermal Stability of Vinylmagnesium Chloride in Tetrahydrofuran
Authors: Rittmeyer P. , Hauk D.
Published: March 2015

An incident at Chemetall’s pilot plant installation during the distillation of dilute solutions of vinylmagnesium chloride in THF caused us to investigate the thermal stability of this Grignard reagent. The on-set temperature for the exothermic decomposition depends on the concentration of the solution. Experiments under isoperibolic conditions provided further information for the determination of safety rules for work with vinylmagnesium chloride.
Kupfer- und Goldkomplexe von Dithiocarbaminsäureestern. Strukturen von [CuCI(L1)3] · CH2Cl2, [AuCl(L1)2], [CuI(L1)(PPh3)]2 und [Cu2
ICuIICl4(L2)2]n (L1 = N-Phenyl-S-methyldithiocarbaminsäureester, L2 = N,N-Dimethyl-S-methyldithiocarbaminsäureester) / Copper and Gold Complexes of Dithiocarbamate Esters. X-Ray Structures of [CuCl(L1)3] · CH2Cl2, [AuCl(L1)2], [CuI(L1)(PPh3)]2 and [Cu2
ICuIICl4(L2)2]n (L1 = N-Phenyl-S-methyldithiocarbamate, L2 = N,N-Dimethyl-S-methyldithiocarbamate)
Authors: Schulbert Klaus , Mattes Rainer
Published: March 2015

Reactions of N-phenyl-S-methyldithiocarbamate (L1) and N,N-dimethyl-S-methyldithio-carbamate (L2) with CuCl2, [Cu2I2(PPh3)3] and HAuCl4 yield the complexes [CuCl(L1)3] • CH2Cl2 (1), [AuCl(L1)2] (2), [CuI(L1)(PPh3)]2 (3) and [Cu2
ICuIICl4(L2)2]n (4). Their structures have been determined by single crystal X-ray crystallography. 1 and 2 are monomeric, with Cu(I) tetrahedrally four-coordinate and Au(I) two-coordinate with an S-Au-S angle of 158.2(1)°. 3 is dimeric with a central CuI2Cu core, the Cu•••Cu distance of which [314.9(1) pm] is rather large. The mixed valence complex 4 has a chain structure with the identity period CuII(μ-Cl)2CuI(μ-S)2CuI(μ-Cl)2. CuI is in a tetrahedral, CuII in a square planar environment. The (μ-S)2 bridged CuI ••• CuI distance is only 259.1(1) pm. The structures of the CuX2Cu cores of 3 and 4 are mainly determined by steric interactions of the donor atoms within the coordination spheres of the metal centers.
Borchelate mit Hydroxamsäuren: Bis(hydroximato)borate / Boron Chelates with Hydroxamic Acids: Bis(hydroximato)borates
Authors: Bessler Eberhard , Deflon Victor M. , Weidlein Johann
Published: March 2015

Potassium and triethylammonium salts of bis(acetohydroximato)borate and bis(benzohydroximato)borate have been prepared by reaction of boric acid with the corresponding hydroxamic acid and potassium bicarbonate or triethylamine, respectively. The compounds have been characterized by elemental analysis, IR, Raman and NMR spectra (1H and 11B).
Direct Synthesis of Tetranuclear Complexes of Copper(II) with μ4-Bridging Oxygen
Authors: Pavlenko Vadim , Kokozay Vladimir , Babich Olga
Published: March 2015

The direct synthesis of a number complexes with general composition Cu4OCl6 - n(CH3)2NH · mSolv, where n = 4, m = 0-2 and Solv = CH3OH, DMSO, is reported. It is shown by X-ray structure investigation, that in Cu4OCl6.4 (CH3)2NH the copper atoms are linked by μ4-oxygen and μ2-chlorine bridging atoms, while molecules of (CH3)2NH are attached to the metal atoms via nitrogen ones
Polysulfonylamine, LI [1]. Synthese von zwei Kronenether-Komplexen des Kaliumdimesylamids und Kristallstruktur von [K(18-Krone-6)] [N(SO2CH3)2] • 2 CH3OH bei —95°C / Polysulfonylamines, LI. Synthesis of Two Crown Ether Complexes of Potassium Dimesylamide and Crystal Structure of [K(18-Crown-6)][N(SO2CH3)2] • 2 CH3OH at –95°C
Authors: Blaschette Armand , Safari Firouz , Nagel Karl-Heinz , Jones Peter G.
Published: March 2015

The complexes [K(18-crown-6)][N(SO2CH3)2] and [K(dibenzo-18-crown-6)][N(SO2CH3)2] are obtained as white solids from equimolar methanolic solutions of KN(SO2CH3)2 and the appropriate crown ether. The former complex crystallizes at -25°C from methanol as a labile (1/2) solvate (title compound). The crystallographic data of the solvate at -95°C are: orthorhombic, space group P 212121, a = 848.2(4), b = 1233.2(4), c = 2496.6(10) pm, V = 2.612 nm3, Z = 4, Dx, = 1.373 Mg m-3. The structure in the solid state consists of ion pairs. The potassium cation is coordinated by the six oxygen atoms of the crown ether and two oxygen atoms belonging to different sulfonyl groups of the anion. The bond distances are K - O(crown) 274.2-297.1 (mean value 288.7), K-O(sulfonyl) 283.8 and 284.5 pm. The potassium ion lies 74 pm out of the best plane of the crown ether oxygen atoms. One methanol molecule acts as a hydrogen-bond donor towards the nitrogen atom of the anion and as a hydrogen-bond acceptor towards the second methanol molecule. The coronand displays the frequently observed symmetry D3d
X-Ray Structure, Electrochemical and Electronic Spectroscopic Examination of Cobaloximatic Acid: Hydro-trans-diiodobis(ethanedioximato(1-)-N,N′)cobaltate(III). Extended Intermolecular O-H-O Bridging in the Solid
Authors: Mégnamisi-Bélombé Michel , Jokwi Irene , Ngameni Emmanuel , Roux Robert , Nuber Bernhard
Published: March 2015

The structure of the cobaloximatic acid, hydro-trans-diiodobis(ethanedioximato(1-)-N,N′)cobaltate(III), has been determined by X-ray diffraction. Crystal data: C4H7CoI2N4O4, Mr = 487.87; monoclinic space group P21/a (C2h
5 ); a = 10.795(7), b = 9.003(7), c = 11.881(6) Å; β = 97.29(6)°; V = 1145.35 Å3; Z = 4; dc = 2.83 Mg m-3. Rw (R) = 3.6 (3.9)% for 3064 observed independent reflections and 148 parameters. The coordination geometry around CoIII is a distorted (4 + 2) octahedron of four chelating equatorial N atoms and two apical iodides. The compound is most adequately formulated as a monovalent strong acid: H(Co(GH)2I2) (GH- = ethanedioximate or glyoximate). The H atoms of the oxime groups are involved in the usual intramolecular, as well as in much stronger intermolecular O-H-O bridgings (O ••• Ointramol = 2.613-2.631, O ••• Ointramol = 2.454 A). The “acidic” H atom of each molecule participates in the intermolecular bridging which extends throughout the structure, and propagates nearly parallel to the [101] crystallographic direction. The redox properties of the present compound were examined by cyclic voltammetry in acetonitrile solution at room temperature. Redox waves attributed to the reduction of CoIII and to the oxidation of I- were observed, along with a wave which may be linked to the reduction of the “acidic” proton
Synthesis of 3-Alkylcoumarins and 3-Alkyl-α,β-unsaturated δ-Lactones from 3-Diethylphosphonocoumarins, 3-Diethylphosphonolactones and Aldehydes
Authors: Falsone G. , Cateni F. , De Nardo M. M. , Darai M. M.
Published: March 2015

The treatment of salicylaldehyde 1 and derivatives 2-4 with triethyl phosphonoacetate 5 in refluxing toluene using piperidine acetate and β-alanine affords 3-diethyl phosphonocoumarins 6-9. By hydrogenation of the compounds 6-9, 3-diethylphosphono-3,4-dihydrocoumarins 10-13 have been obtained. The compounds 10-13 react with the aromatic aldehydes 14-18, under Wittig-Horner conditions, to give 3-alkyl-coumarins 19-24 in satisfactory yields. The reaction of 3-diethyl-phosphonolactones 25, 26 with isatin 27 and 5-bromoisatin 28, under similar reaction conditions, leads to 3-alkyl-α,β-unsaturated δ-lactones 29-31
6-Bromo-5-hydroxy-3-indolecarboxyaldehyde from the Caribbean sponge Oceanapia bartschi
Authors: Cafieri Francesco , Fattorusso Ernesto , Mahajnah Yosef , Mangoni Alfonso
Published: March 2015

The organic extract from Oceanapia bartschi has been shown to contain the antibiotic diterpene Ambliol A (1) and three indole derivatives, 3-bromoindole (2), 6-bromo-3-indolecarboxyaldehyde (3), and 6-bromo-5-hydroxy-3-indolecarboxyaldehyde (4). The structure of the novel compound 4 has been established from its spectroscopic (1H and 13C NMR, UV, IR, and MS) data
Zur Cycloaddition von Azidoameisensäuremethylester an die Metall-Carben-Doppelbindung in η2-Thiocarbenkomplexen des Molybdäns und Wolframs / Cycloaddition of Azidoformic Acid Methylester to the Metal Carbon Double Bond of η2-Thiocarbene Complexes of Molybdenum and Tungsten
Authors: Kreißl Fritz R. , Schutt Wolfgang , Ostermeier Josef , Stegmair Claudia M. , Ullrich Waltraud , Herdtweck Eberhardt
Published: March 2015

Cationic η2-thiocarbene complexes of molybdenum and tungsten [Cp(CO)PMe3

[BF4] (R = Me, Ph, Tol) add N3COOMe to the electron rich metal carbon double bond to yield the corresponding bicyclic system. The products have been characterized by 1H, 13C, 31P NMR, IR and mass spectra. The crystal structure of 4b has been determined: space group P21/n with a = 1749.9(7), b = 827.9(1), c = 1846.8(7) pm and Z = 4.
Sulfurization and Selenization of the Halfsandwich Nitrosylmetal Complexes Cp*M(CO)2NO (M = Cr, Mo) and Cp*M(NO)I2 (M = Mo, W)
Authors: Herberhold Max , Jin Guo-Xin , Rheingold Arnold L.
Published: March 2015

The photo-induced decarbonylation of Cp*Cr(CO)2NO in acetonitrile solution in the presence of excess sulfur leads to the cyclo-pentasulfido complex Cp*Cr(NO)(S5) (1 a), while in the case of limited sulfur supply the binuclear bis(µ-disulfido) complex Cp*2Cr2(NO)2(µ-S2)2 (4a) is formed preferentially. The corresponding reaction with elemental selenium produces Cp*2Cr2(NO)2(µ-Se2)2 (4b), irrespective of the available amount of selenium. Photodecarbonylation of Cp*Mo(CO)2NO gives only the binuclear derivates Cp*2Mo2(NO)2(µ-E2) (E = S (5a), Se (5b)) which are also obtained by treating Cp*Mo(NO)I2 with H2S or H2Se, respectively. Nitrosyl loss predominates if the tungsten complex Cp*W(NO)I2 is reacted with H2S; in an argon atmosphere the products are Cp*W(S)(S2)(I) (7a) and Cp*2W2(S)2(µ-S)2 (8a), while in air some Cp*W(NO)(S5) (3a) and the oxo compounds Cp*W(O)(S2)I (7c), Cp*2W2(O)2(µ-S)2 (8c) and Cp*2W2(S)(O)(µ-S)2 (8d) are formed. The analogous reaction with H2Se leads to Cp*W(NO)(Se5) (3b), Cp*2W2(O)2(µ-Se)2 (9c) and Cp*2W2(Se)(O)(µ-Se)2 (9d), respectively. The binuclear tungsten complexes 8a,c,d and 9c,d contain a central W(µ-E)2W framework (E = S or Se) which is unaffected by air, while terminal sulfido and selenido ligands are quantitatively converted into the corresponding terminal oxo ligands in the presence of air in CH2C12 or THF solution. With the preparation of Cp*2W2(O)2(µ-E)2 (E = S (8c) and Se (9c)), the series of dioxo complexes containing a pair of monochalcogen bridges (E = O, S, Se, Te) has become complete.

The new complexes have been characterized by their IR (v(NO)), 1H and 13C NMR (Cp*) spectra as well as by electron-impact mass spectrometry. According to the X-ray structure analyses, the binuclear compounds Cp*2Cr2(NO)2(µ-S2)2 (4a) and Cp*2Mo2(NO)2(µ-Se2)2 (5b) contain two 14-electron [Cp*M(NO)2] fragments which are connected by a pair of dichalcogen (η1,η2-E2) bridging ligands (M = Cr or Mo, E = S or Se). The central M2E2 four-membered ring is not planar, and the binuclear molecules are chiral.
Ferrocen-Derivate der Quadrat- und Propiolsäure. Synthesen und Reaktionen / Ferrocene Derivatives of Squaric Acid and Propiolic Acid. Syntheses and Reactions
Authors: Schottenberger Herwig , Buchmeiser Michael , Polin Johann , Schwarzhans Karl-Eberhard
Published: March 2015

Concepts for linking ferrocene derivatives with conjugated squarate and propiolate based spacer systems have been investigated. Coupling of 3,4-dichlorocyclobut-3-ene-1,2-dione (squaric acid dichloride) with cuproferrocene • dimethylsulfide resulted in 3-chloro-4-ferrocenylcyclobut-3-ene-1,2-dione (ferrocenylsemisquaric acid chloride) and 3,4-diferrocenylcyclobut-3-ene-1,2-dione. Ferrocenylsemisquaric acid chloride was further treated with ethynylferrocene and 4-ethynyl-4-(ferrocenylethynyl)tolan, respectively, to form the corresponding mixed squaric diketones, which required Zn/Pd mediated coupling conditions for sufficient conversion. The symmetrically substituted derivative of ferrocenylacetylene was prepared by the same method.

Cupration and subsequent coupling of dilithioferrocene with one equivalent of iodopropiolic acid methyl ester yielded 1′-iodo- 1 -ferrocenylpropiolic acid methyl ester, and with two equivalents 1,16-bis(methoxycarbonylethynyl)biferrocene. Nucleophilic addition of secondary amines to ferrocenylpropiolic acid ethyl ester gave aminoacrylates as intermediates, which rapidly converted to ketoesters during workup. Only in the case of morpholine the corresponding adduct (ferrocenylmorpholino acrylate) could be isolated. 1,3-Diferrocenylprop-2-ene-1-one has been obtained in a Bénary reaction of lithioferrocene with 3-diethylaminoethyl acrylate in quantitative yield.

In order to provide alternative syntheses of already known compounds the substitution behavior of different metallated ferrocene intermediates has also been evaluated by reaction with other acid halides (oxalyl chloride, thiophosgene, ethyl chloroformate).

All new compounds, 3-chloro-4-ferrocenylcyclobut-3-ene-1,2-dione (1); 3,4-diferrocenylcyclobut-3-ene-1,2-dione (2); 3,4-diferrocenylethynylcyclobut-3-ene-1,2-dione (3); 3-ferrocenyl-4-ferrocenylethynylcyclobut-3-ene-1,2-dione (4); 3-ferrocenyl-4-ferrocenylethynylphenylethynylphenylethynylcyclobut-3-ene-1,2-dione (5); 3-(N-morpholino)-3-ferrocenylethyl acrylate (6); 3-ferrocenyl-3-ketoethyl propanoate (7); iodoferrocenylpropargylic acid methyl ester (8); 1,16-bis(methoxycarbonylethynyl)biferrocene (9) and trans-1,3-diferrocenylprop-2-ene-1-one [105 404-21-5], have been characterized by IR, MS and NMR and in several cases by UV/VIS and DSC.
Vier- und fünffach koordinierte Organometall-Phosphankomplexe von Aluminium, Gallium, Indium und Thallium / Four- and Five-Coordinate Organometal Phosphine Complexes of Aluminum, Gallium, Indium, and Thallium
Authors: Müller Gerhard , Lachmann Joachim
Published: March 2015

The organometal phosphine complexes ML3 (L = [o-(Ph2PCH2)C6H4]-; M = Al3+, Ga3+, In3a+) are obtained from MC13 and the lithiated ligand in diethyl ether. Tl[o-(Ph2PCH2)C6H4]3 is prepared from T1C1 by a disproportionation reaction. M1 species could not be detected with L as ligand. Al[o-(Ph2PCH2)C6H4]3 is the first triorganoaluminum bis(phosphine) adduct where C3P2 pentacoordination at aluminum has been definitely proven for both the solution (δ(27Al) =131 ppm, w1/2 = 12 kHz) and the solid state (d(Al–P) = 2.676(3)/2.782(2) A). The trigonal-bipyramidal coordination geometry (C3P2) at Al is achieved by two of the anionic phosphines acting as chelating ligands, spanning equatorial (C atoms) and axial sites (P atoms), while the third phosphine is only carbon-bonded. Like AlL3, the heavier congeners ML3 (M = Ga, In, Tl) are stereochemically nonrigid molecules in solution. Surprisingly, in the solid state only InL3 resembles the aluminum complex (C3P2 penta-coordination) while GaL3 and T1L3 contain four-coordinate metal centers (C3P). This may be rationalized by the noticeably less polar Ga–P bonds as compared to Al–P and In–P bonds, while in T1L3 the span of the ligand is not sufficient to allow for chelating coordination at a five- (or six-)coordinate Tl center.
Beeinflussen interne N-Donorliganden Hydrolyse-und Kondensationsreaktionen von Chlorsilanen? / Do Internal N-Donor Ligands Influence the Hydrolysis and Condensation Reactions of Chlorosilanes?
Authors: Auner Norbert , Probst Reiner , Heikenwälder Claus-Rüdiger , Herdtweck Eberhardt , Gamper Siegfried , Müller Gerhard
Published: March 2015

The reaction of [C6H4CH2N(CH3)2]2SiCl2 (1) with hydrogen chloride gives the singly protonated adduct 2. Its solid state structure has been determined by single crystal X-ray diffraction. Centrosymmetric 2 is orthorhombic, space group Pbca, a = 1694.9(2), b = 1161.7(2), c = 2501.7(3) pm; Z = 8. Controlled hydrolysis of 1 leads to the 1,3-siloxanediol 4, probably via the precursors 3a-3c which could not be isolated. The hydrogen chloride formed during the hydrolysis protonates two of the dimethylamino groups, while the other two dimethylamino functions form hydrogen bonds to the silanol groups. Centrosymmetric 4: monoclinic, space group P21/c, a = 980.3(1), b = 933.9(1), c = 2177.5(2) pm, β = 99.94(1)°; Ζ = 4. If the hydrolysis is carried out in the presence of lithium naphthalenide, the metalated compound {[C6H4CH2N(CH3)2]2Si(OLi)OH}4•2 LiCl•2CHCl3 (5) is obtained. The solid state structure of 5 exhibits two cube-like subunits which are held together by nitrogen and oxygen lithium contacts, hydrogen bonds between silanol groups and nitrogen atoms, and which are linked by the four silicon centres. Tetrameric 5: monoclinic, space group C2/C or Cc; a = 1523.6(2), b = 2440.2(1), c = 2534.8(2) pm, β = 93.83(3)°; Ζ = 8. These results show that the intramolecular donor capabilities of the dimethylaminobenzyl ligand at silicon can stabilize 1,3-siloxanediol and SiOLi substructures. Compounds like 1 serve as model compounds for the controlled formation of precursors for silicone synthesis.
Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XLII [1]: Photoreaktionen von Hexacarbonyl-μ-η5:5-fulvalen-dimolybdän und -diwolfram mit konjugierten Dienen / Hindered Ligand Movements in Transition Metal Complexes, XLII [1]: Photoreactions of Hexacarbonyl-μ–η5:5-fulvalene-dimolybdenum and -ditungsten with Conjugated Dienes
Authors: Kreiter Cornelius G. , Conrad Wolfgang , Exner Reiner
Published: March 2015

Photochemical reactions of hexacarbonyl-μ-η5:5-fulvalene-dimolybdenum (1) with 1,3-butadiene (a), 2-methyl-1,3-butadiene (b), E-1,3-pentadiene (c), 2,3-dimethyl-1,3-butadiene (d), and E-3-methyl-1,3-pentadiene (e) yield the corresponding tetracarbonyl-η4-s-cisdiene-μ-η5:5-fulvalene-dimolybdenum complexes 3a-3e. In addition to 3a also η4-s-trans1,3-butadiene-tetracarbonyl-μ-η5:5-fulvalene-dimolybdenum (4) is formed. Similarily hexacarbonyl-μ-η5:5-fulvalene-ditungsten (2) forms with a and b tetracarbonyl-η4-s-cis-diene-μ-η5:5-fulvalene-ditungsten (5a, 5b) and bis(η4-s-cis-1,3-butadiene)-dicarbonyl-μ-η5:5-fulvalene-ditungsten (6). The complexes 3b —3e and also 5b are obtained as mixtures of the o- and u-isomers. Only for tetracarbonyl-η4-cis-2,3-dimethyl-1,3-butadiene-μ-η5:5-fulvalene-dimolybdenum (3d) an interconversion of the o- and u-isomers is observed with an energy barrier of ΔG183
# = 73.9 kJ/mol. Both isomers of 3d show hindered inversions with energy barriers of ΔG#
313 = 66.1 kJ/mol (u-3d) and ΔG183
# = 36.4 kJ/mol (o-3d). For o-3d the crystal and molecular structure was determined by an X-ray diffraction analysis. Hexacarbonylµ — η5:5-bis(cyclopentadiendiyl)methane-dimolybdenum (7), hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)ethane-dimolybdenum and hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)propane-dimolybdenum do not react with conjugated dienes. Upon UV irradiation 7 looses CO and forms by dimerization octacarbonyl-bis(μ-η5:5-(cyclopentadiendiyl-cyclopentadien-triyl)methane)-dihydrido-tetramolybdenum (8).
Synthesis and Structure of a Manxane-Cage Silazane Molecule
Authors: Baier Michael , Bissinger Peter , Schmidbaur Hubert
Published: March 2015

The reaction of tris(chlorodimethylsilyl)methane HC(SiMe2Cl)3 (1) with dry ammonia in hexane leads to the tris(disilazane) molecule HC(Me2SiNHSiMe2)3CH (3) in satisfactory yields. According to its 1H, 13C, and 29Si NMR spectra this bicyclic cage-molecule exhibits virtual (time-averaged) D3h symmetry. In the crystal (rhombohedral, space group R3) the manxane-type structure has a crystallographic three-fold axis, but the structure obeys only D3d symmetry to a good approximation, owing to a disrotatory twist of the two Si3 triangles against each other. The crystals of compound 3 are isomorphous with those of the analogous tris(disiloxane) 2.
tripod-Eisen- und tripod-Cobalt-Komplexe mit Acetonitril als Stützliganden (tripod = RCH2C(CH2PPh2)3; R = H, Ph) / tripod-Iron and tripod-Cobalt-Complexes with Acetonitrile as Supporting Ligands (tripod = RCH2C(CH2PPh2)3; R = H, Ph)
Authors: Asam A. , Janssen B. , Huttner G. , Zsolnai L. , Walter O.
Published: March 2015

The tripod ligands RCH2C(CH2PPh2)3 react with (CH3CN)6Fe(BF4)2 to yield the tripod-Fe(II) complexes RCH2C(CH2PPh2)3Fe(CH3CN)3(BF4)2 (R = H, la; R = Ph, lb). The octahedral low spin Fe(II) compounds are shown by cyclic voltammetry to undergo reversible one electron oxidation at +1.47 V (vs. SCE) to give the corresponding Fe(III) derivatives.

In a similar way (CH3CN)6Co(BF4)2 reacts with the same tripod ligands to produce the tripod-Co(II) complexes RCH2C(CH2PPh2)3Co(CH3CN)2(BF4)2 (R = H, 2a; R = Ph, 2b). The compounds are paramagnetic (2a, g = 2.123; 2b, g = 2.129). The structure of complex 2b shows that the tripod ligand is facially coordinated with one longer (233.1 pm) and two shorter (about 222 pm) Co—P bonds. Reversible reduction is found for 2a at —0.30 V by cyclic voltammetry. The compounds have been characterized by spectroscopic and analytical techniques including X-ray analyses.
The Preparation of Some Monodentate Coordinated Semicarbazone(O) and Thiosemicarbazone(S) Cationic But-2-yne Tungsten(II) Complexes
Authors: Baker Paul K. , Flower Kevin R.
Published: March 2015

Reaction of [WI(CO)(NCMe)(dppm)(η2-MeC2Me)][BF4] {dppm = Ph2P(CH2)PPh2} with an equimolar quantity of L {L = RR′CNNHCONH2 (R = R′ = Me; R = H, R′ = Ph)} or L {L = RR′CNNHCSNH2 (R = R′ = Me, Et; R = Me, R′ = Et, Prn, But, Ph; R = H, R′ = Ph)} gives the monodentately coordinated semicarbazone or thiosemicarbazone products [WI(CO)L(dppm)(η2-MeC2Me)][BF4] (1-9). 13C NMR spectroscopy suggests that the but-2-yne ligand is donating four electrons to the tungsten in [WI(CO){H(Ph)CNNHCSNH2}(dppm)(η2-MeC2Me)] [BF4].
Tieftemperatur-Raman-Messungen an bewegten Proben bei 10 K am Beispiel der Isotopomeren Cs2[Pt35Cln
37Cl6-n, n = 0-6 / Low-Temperature Raman Measurements on Moved Samples at 10 K Exemplified by the Isotopomers Cs2[Pt35Cln
37Cl6-n], n = 0-6
Authors: Preetz W. , Parzich E.
Published: March 2015

A technique to record Raman spectra of deeply coloured solids at low temperature (10 K) is described, using a closed cycle He-cryogenerator and moving the cell by an excentric attachment. The spectroscopic resolution is considerably enhanced as compared to room temperature or 80 K measurements. This is obvious from splittings of Raman lines observed at 10 K on the isotopomers Cs2[Pt35Cln
37Cl6-n], n = 1 -5, which have been prepared by stereospecific ligand exchange reactions. As a consequence of lowered symmetry the degenerate valence vibration v2(Eg, Oh) is split into two lines for the isotopomers belonging to the point groups D4h, C4v and C2v. The isotopic effects calculated by normal coordinate analysis are in good agreement with the observed frequencies.
Iminoacetylacetonat-Komplexe der Lanthanoide: Synthese, Eigenschaften und Struktur / Iminoacetylacetonate Complexes of Lanthanides: Synthesis, Properties and Structure
Authors: Thiele Karl-Heinz , Scholz Annett , Scholz Joachim , Böhme Uwe , Kempe Rhett , Sieler Joachim
Published: March 2015

The reactions of (η5-C5Me5)2Ln(μ-Cl)2ML2 (Ln = Y, La, Lu; M = Li, K; L = Et2O, dme) 3a-c with the sodium iminoacetylacetonates 2a-b yield monomeric metallocene chelate complexes

, (Ln = Y, La, Lu; R = C6H5, C6H4-4-Me) 4a-d which have been characterized by IR, NMR and mass spectrometry. In the case of the lanthanum complex 4c, the chelating structure was confirmed by an X-ray structure analysis. 4c crystallizes monoclinically in space group P21/c with a = 10.232(3), b = 10.216(1), c = 29.047(7)Å, α = γ = 90.0°, β = 97.76(3)°, Ζ = 4, and R = Rw = 0.0378 for 4026 observed reflections. The new complexes are sensitive to oxygen and moisture and soluble in all common organic solvents.
Synthese und Kristallstruktur von Iodmethyltriphenylphosphonium-iodid (C6H5)3PCH2I+I- / Synthesis and Crystal Structure of Iodomethyltriphenylphosphonium Iodide (C6H5)3PCH2I+I-
Authors: Vogt H. , Lauritsen K. , Riesel L. , Löwis M. von , Reck G.
Published: March 2015

Iodomethyltriphenylphosphonium iodide, (C6H5)3PCH2I+I-, has been prepared by the reaction of (C6H5)3P with CH2I2 in dichloromethane forming colourless needle like crystals. The crystal and molecular structures have been determined by an X-ray structure analysis. The crystals are orthorhombic, space group Pca21, Z = 8; a = 1478,8(3) pm, b = 1249,3(3) pm, c = 2053,2(3) pm. R = 0.050 for 3219 observed reflections with I ≥ 2 σ(Ι). In the solid state the title compound exists as two discrete monomeric units, (C6H5)3PCH2I+I-. In both symmetry independent units the I-I distances are surprisingly short with 346,5(1) pm and 356,3(1) pm. For the title compound the results of AM 1, PM 3, and MNDO calculations are in good agreement with corresponding values determined by the X-ray analysis.
The Crystal Structures of Re2Al, Re4Al11, and ReAl6
Authors: Niemann Sabine , Jeitschko Wolfgang
Published: March 2015

Well-crystallized samples of the rhenium aluminides Re4Al11 and ReAl6 were obtained by reaction of rhenium with an excess of aluminum. Re4Al11 was found to be isotypic with Mn4Al11. The MnAl6 type structure of ReAl6 was confirmed. The crystal structures of both compounds were refined from single-crystal X-ray data. Re4Al11:P1̄, Z = 1, a = 516.0(1) pm, b = 896.3(2) pm, c = 516.9(1) pm, a = 90.44(1)°, β = 99.76(1)°, γ = 105.17(1)°, V = 0.2271 nm3, R = 0.036 for 2315 structure factors and 74 variable parameters. ReAl6: Cmcm, Z = 4, a = 761.0(1) pm, b = 660.5(1) pm, c = 903.4(1) pm, V = 0.4541 nm3, R = 0.013 for 711F values and 23 variables. In both structures the rhenium atoms have ten aluminum neighbors at distances from 245 to 277 pm. The Al-Al distances cover the whole range from 251 to 362 pm rather continuously. The previously reported compound Re2Al with the tetragonal MoSi2-type structure has the lattice constants a = 298.1(1) pm, c = 958.4(4) pm, V = 0.08519 nm3. ReAl6 shows Pauli-paramagnetism.
Übergangsmetall-substituierte Acylphosphane und Phosphaalkene, XIX / Transition Metal Substituted Acylphosphanes and Phosphaalkenes, XIX
Authors: Weber Lothar , Kaminski Olaf , Stammler Hans-Georg , Neumann Beate , Romanenko Vadim D.
Published: March 2015

The metallo-phosphaalkenes (η5-C5Me5)(CO)2M-P=C(NR2)2 (4a,b, 5) result from the reaction of the corresponding bromo compounds (η5-C5Me5)(CO)2MBr with Me3Si-P=C(NR2)2. The complexes 4a and 5a are cleanly converted into the 1-metallo- l ,2-dihydrophosphetes

(10a-c) (M = Fe, Ru; E = CO2Me, CN) by treatment with equimolar amounts of dimethyl fumarate or fumarodinitrile, respectively. The products 4a,b, 5 and 10 a-c have been characterized by elemental analysis as well as by spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structures of 4a and 10a have been determined by single crystal X-ray analysis.
Liquid Crystalline Compounds in the Thiophene Series, Part 7+
Authors: Koßmehl Gerhard , Hoppe Frank Dirk
Published: March 2015

Compounds with two mesogenic groups without terminal alkyl chains or other groups containing thiophene systems have been prepared from α.ω-bis(5-formyl-2-thienyl)alkanes (series 1) and various phosphonium salts by Wittig-reaction. The chemical structures of the new compounds have been characterized by their elemental analyses, IR and 1H NMR spectra and MS. The liquid crystalline properties of these compounds were characterized by differential scanning calorimetry (DSC) and polarizing microscopy. Mesogenic cores with one thiophene system and two benzene systems give rise to liquid crystalline phases. These compounds with one vinylene group in each core (series 2 and 3) are mostly monotropic, those with two or three vinylene groups are enantiotropic liquid crystalline. Exchanging one vinylene group by a azomethine group in each core reduces the temperature range of the mesophase or destroys the liquid crystallinity completely. In contrast to E,E-1-(5-butyl-2-thienylvinyl)-4-(styryl)benzene (9) with no mesophase the corresponding all-E-α.ω-bis{5-[4-(4-styryl)styryl]-2-thienyl}alkanes (series 5) show over a wide temperature range with increasing inner chain length more and more high ordered mesophases. all-E-α.ω-Bis{5-[4-(4-phenylbuta-1.3-dienyl)styryl]-2-thienyl}alkanes (series 7) decompose in their mesophases.
Notizen: CsNaS - das erste Interalkalimetallsulfid mit Cäsium / CsNaS - the First Inter Alkali Metal Sulfide with Cesium
Authors: Sabrowsky Horst , Feldbaum-Möller Elisabeth , Winter Volker , Vogt Petra
Published: March 2015

The grey compound CsNaS has been prepared. The characterization by X-ray powder methods leads to a tetragonal lattice (P 4/nmm) with a = 482.1(1), c = 785.6(2) pm and Z = 2. The structure is related to the PbFCl structure type.
Über die Wechselwirkung des Vanadyl(IV)-Kations mit Nucleobasen / Interaction of the Vanadyl(IV) Cation with Nucleic Bases
Authors: Williams P. A. M. , Etcheverry S. B. , Baran E. J.
Published: March 2015

The interaction of VO2+ with the nucleic bases adenine, guanine, cytosine, thymine and uracil has been investigated spectrophotometrically in a wide pH-range and with metal to base ratios 1:1 and 1:10. Adenine, guanine and uracil interact with the cation at pH-values >5, but whereas adenine apparently coordinates through Natoms, the other two bases seem to be coordinated through oxygen donors.