bluuebunny/crossref_metadata_2025 huggingface dataset:
Palladium-Catalyzed Coupling Reaction of 3-Bromo Benzo[b]furan, -thiophene and -selenophene 2-Carboxaldehyde. Preparation of Tetracyclic Heteroaromatic Derivatives
Authors: Kirsch Gilbert , Deprets Stéphanie
Published: February 2015

3-Oxo-2,3-dihydrobenzo[b]furans, -thiophenes and -selenophenes 1a - c afforded the bromo-aldehydes 2 under Vilsmeier-Haack-Arnold conditions. Palladium-catalysed aryl-aryl coupling of 2 with o-formyl-phenylboronic acid allowed the formation of dialdehydes 3 which underwent McMurry cyclisation or pinacol condensation to yield polycyclic aromatic derivatives 4 or the dihydroxylated compounds 5
Orthoamide, LXIII [1]. Tris(dichlormethyl)amin, ein neues breit anwendbares Formylierungsmittel für Aromaten / Orthoamides, LXIII [1]. Tris(dichloromethyl)amine, a New Formylating Reagent for Aromatic Compounds of Wide Scope
Authors: Kantlehner Willi , Kreß Ralf , Zschach Franziska , Vetter Jens , Ziegler Georg , Mezger Jochen , Stoyanov Edmont V. , Goeppert Alain , Sommer Jean , Wezstein Markus
Published: February 2015

The reagent system formed from tris(dichloromethyl)amine (5) and aluminium chloride allows the formylation of aromatic compounds. The scope of the method is comparable with that of the Olah formylation and the Groß-Rieche procedure, since benzene and even chlorobenzene can be formylated. One formyl group is transferred from 5 to the aromatic nucleus. In order to find optimal reaction conditions, the molar amounts of aromatic compounds, 5 and aluminum chloride were varied as well as reaction temperatures and solvents. The activation of 5 with other Lewis acids is also described
Synthesis of N,N’-Linked Isothiazolium Salts via Intramolecular Cyclocondensation of Hydrazonium Salts
Authors: Zakharova Valerija M. , Siegemund-Eilfelda Anja , Sieler Joachim , Schulze Bärbel
Published: February 2015

Interaction of β -thiocyanatovinyl aldehydes with N-amino heterocycles leads to formation of α, β - unsaturated hydrazonium salts dependent on the functional surroundings. The latter can undergo further intramolecular cyclocondensation giving rise to N,N′-linked isothiazolium salts as the final product. The isolated hydrazonium salts, not undergoing ring formation, have s-trans conformation of the azadiene system
Two-Step Synthetic Approach to 6-Substituted Pyrido[2,3-d]pyrimidine(1H,3H)-2,4-diones from 6-Amino-, 6-Alkylamino-, and 6-Arylamino-1,3-dimethyluracils
Authors: Bischoff Kerstin , Girreser Ulrich , Heber Dieter , Schütt Martin
Published: February 2015

The Mannich reaction of 7-aryl-5,6-dihydropyrido[2,3-d]pyrimidines 3, easily accessible by condensation of 6-amino-1,3-dimethyluracil (1) with Mannich bases 2a - c, gives rise to a mixture of 7-aryl-6-(N,N-dimethylaminomethyl)pyrido[2,3-d]pyrimidines 6 and 7 as well as 1,2-bis- (7-arylpyrido[2,3-d]pyrimidin-6-yl)ethane 13 the ratio of which depends on the reaction conditions and the amine used. 6-Alkylamino-1,3-dimethyluracils 15 - 18 were converted to the corresponding 5-(3-oxo-3-phenylpropyl)uracils 19 - 22 by condensation with the Mannich base 2a. Ring closure of 19 - 22 was performed by Vilsmeier formylation to afford the 8-alkyl- and 7,8-diaryl-5,8- dihydropyrido[2,3-d]pyrimidine-6-carbaldehydes 9 - 12 via the corresponding iminium salts 27 - 30
Piperidino Substituted [1]Borametallocenophanes. Synthesis, Reactivity, and Structure
Authors: Braunschweig Holger , Kraft Mario , Radacki Krzysztof , Stellwag Sascha
Published: February 2015

ansa-Metallocenes and related complexes have considerable potential as catalyst precursors in the Ziegler-Natta type olefin polymerization. In the present paper we report about the synthesis of piperidinyl-substituted [1]borametallocenophanes of titanium and zirconium. Furthermore, the first example of a base stabilized alkyl-substituted [1]borazirconocenophane was fully characterized and tested for its properties in the polymerization of ethene.
Bis[1,3-dimethylbarbituryl(5)]sulfid – Struktur und Reaktionen/ Bis[1,3-dimethylbarbituryl(5)]sulfide – Structure and Reactions
Authors: Kuhn Norbert , Maichle-Mößmer Cäcilia , Steimann Manfred , Sweidan Kamal
Published: February 2015

Bis[1,3-dimethylbarbituryl(5)]sulfide (3, [BarbH]2S, BarbH = 1,3-dimethylbarbitur-5-yl) was obtained from 1,3-dimethylbarbituric acid (2) and SCl2 or SOCl2. The compound 3 reacted with 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (7, Im) to give the imidazolium salts [ImH][BarbH-S-Barb] (8) and [ImH]2[Barb-S-Barb] (9) in which the ions are linked by hydrogen bonds. From 3 and triphenylphosphane, the zwitterionic compound Barb-S-PPh3 (10) was obtained. The crystal structures of the compounds 3, 8, 9 and 10 were discussed.
Thallium(I) Salicylate and Phthalate: Syntheses and Structural Characterization
Authors: Askarinejad Azadeh , Torabi Ali Asgar , Morsali Ali
Published: February 2015

Two new 2D polymers, thallium(I) hydrogensalicylate (1) and hydrogenphthalate (2), have been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The single-crystal X-ray data show the coordination number of the TlI ions of compounds 1 and 2 to be four and six with the environment TlO4 and TlO6, respectively. The arrangement of the O atoms suggests a gap in the coordination geometry around the thallium atoms in both compounds, due to a stereo-chemically ‘active’ electron lone pair of TlI. There is another interaction between the thallium atom and the carbon atoms of an aromatic ring in compound 1, giving a total hapticity of ten with the environment C6O4Tl.
Anionic Tungsten Carbonyl Complexes Containing Dithiocarboxylate, Dithiocarbamate, and Xanthate Ligands
Authors: Dilsky Stefan , Schenk Wolfdieter A.
Published: February 2015

The reaction of Et4N[W(CO)5Cl] with sodium dithiobenzoate, ethylxanthate, or various dithiocarbamates gave the corresponding salts Et4N[W(CO)4(SSCX)] (X = Ph, NEt2, N(H)t-Bu, NPh2, OEt) which contain the dithio ligand in a chelating bonding mode. Two of them (X = N(H)t-Bu, NPh2) were characterized by X-ray crystallography. The tungsten atom resides in the center of a slightly distorted octahedron surrounded by a symmetrically bidentate planar dithio ligand and four CO groups. Reaction with PPh3 or PMe3 at elevated temperature gave the tricarbonyl complexes Et4N[W(CO)3(PR3)(SSCX)] and in one case a ring-opened addition product, Et4N[W(CO)4(PMe3)(SC(S)OEt)]. For two of them X-ray structure determinations were carried out. A comparison of the four structures shows that while the W-C bond length decreases progressively with increasing electron density at the tungsten atom, the W-S and W-P bond lengths remain essentially constant.
1,3,5-Triphosphorinane. Synthese und Struktur der Isomeren des 1,3,5-Triphenyl-1,3,5-triphosphorinans/ 1,3,5-Triphosphorinanes. Synthesis and Structure of the Isomers of 1,3,5-Triphenyl-1,3,5-triphosphorinane
Authors: Fild Manfred , Jones Peter G. , Lorms Michael , Jäger Stefan
Published: February 2015

The reaction of lithiated Ph(H)PCH2P(H)Ph with (ClCH2)2PPh yields 1,3,5-Triphenyl-1,3,5- triphosphorinane (1) as a mixture of two isomers. The isomers have been separated by column chromatography and characterized by NMR spectroscopy and single crystal X-ray diffraction as the eq-eq-eq (1a) and eq-eq-ax-isomers (1b). (1a) crystallizes with a = 1326.9(3) pm and c = 933.4(3) pm in the rhombohedral space group R3 and displays 3-fold symmetry, showing an eq-eq-eq conformation. (1b) crystallizes in the monoclinic space group P21/c with a = 984.09(12) pm, b = 1757.5(2) pm, c = 1083.13(12) pm, β = 93.329(2)° and displays an ax-eq-eq conformation.
Growth of NaBr in the 5-5 Structure Type on LiNbO3: A Feasibility Study
Authors: Schön J. Christian , Dinges Tim , Jansen Martin
Published: February 2015

The feasibility of growing alkali halides in the hypothetical 5-5 structure type on a specially prepared substrate of LiNbO3 has been investigated. The highest degree of steering towards this structure is achieved by growing NaBr on a LiNbO3 (001)-surface, where the outermost layer of oxygen atoms is followed by a layer of niobium atoms. The kinetic stability, against transition into the rock salt structure, of the 5-5 structure grown on the substrate is enhanced compared to the bulk 5-5 phase, but the 5-5 structure will nevertheless still be metastable compared to the rock salt structure type that constitutes the thermodynamically stable bulk phase of NaBr under standard conditions
Stannides and Intermetallic Tin Compounds – Fundamentals and Applications
Authors: Pöttgen Rainer
Published: February 2015

Tin, tin alloys and intermetallic tin compounds play a key role in many technologies and high-tech applications. Many of these intermetallics find application in daily life such as pewterware, bronzes, solders, fusible alloys, superconductors, capsules for wine bottles or tinplate packaging. Many of the applications are directly related to distinct stannides or intermetallic tin compounds. The crystal chemistry and chemical bonding of these materials as well as their applications are briefly reviewed
Hydrothermal Crystal Growth and Crystal Structures of the Mercury(II) Chromates(VI) α-HgCrO4, β-HgCrO4, and HgCrO4·H2O
Authors: Stöger Berthold , Weil Matthias
Published: February 2015

Single crystals of α-HgCrO4, β -HgCrO4 and HgCrO4 ・ H2O were obtained by reacting yellow HgO in chromic acid of various concentrations under hydrothermal conditions at 200 °C (4 d). All crystal structures were solved and refined from single crystal diffractometer data sets [α-HgCrO4: P21/n, Z = 4, a = 5.5079(8), b = 8.5266(12), c = 7.3503(10) Å , β = 94.022(3)°, 955 structure factors, R[F2 > 2σ (F2)] = 0.0296; β -HgCrO4: Cmcm, Z = 4, a = 5.7187(9), b = 9.0169(14), c = 7.0114(11) Å, 361 structure factors, R[F2 > 2σ (F2)] = 0.0275; HgCrO4 ・ H2O: P1̅, Z = 2, a=5.6157(15), b =6.1115(16), c= 7.590(2) Å , α =108.850(5), β =91.666(5), γ =116.569(5)°, 1235 structure factors, R[F2 > 2σ (F2)] = 0.0316]. The previously reported structure of α-HgCrO4 has been re-determined. It contains distorted [HgO7] pentagonal bipyramids in which the short bonds are directed towards the apices. The new polymorph β -HgCrO4 adopts the CrVO4 (β -CrPO4) structure type and is composed of slightly distorted [HgO6] octahedra. The previously unknown monohydrate HgCrO4 ・ H2O crystallizes in an unique structure and is composed of one nearly regular [HgO4(H2O)2] octahedron and one considerably distorted [HgO6] octahedron. All three structures contain tetrahedral chromate anions CrO4
2− as the second building units with average Cr-O distances of ca. 1.65 Å
Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten, XXXVII [1]. Synthese, Kristallstruktur und kernresonanzspektroskopische Untersuchung von In2Ti6(PO4)6[Si2O(PO4)6] – Eine Hybride aus den NASICON und M4[Si2O(PO4)6] Strukturtypen / Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phospates, XXXVII [1]. Synthesis, Crystal Structure and Nuclear Magnetic Resonance Investigation of In2Ti6(PO4)6- [Si2O(PO4)6] – A Hybride Built from Layers with NASICON and M4[Si2O(PO4)6] Structures
Authors: Schöneborn M. , Hoffbauer W. , Schmedt auf der Günne J. , Glaum R.
Published: February 2015

In2Ti6(PO4)6[Si2O(PO4)6] has been obtained by heating (1100 °C) stoichiometric amounts of In2O3, SiP2O7, TiP2O7, and TiO2 in air. Colourless crystals of the phosphate-silicophosphate suitable for a single crystal structure investigation have been grown by chemical vapour transport (1000°C → 900°C, mixture of 70 mg PtCl2 and 3.5 mg TiP as transport agent). In2Ti6(PO4)6[Si2O(PO4)6] adopts its own structure type (R3̅ (No. 148), Z = 3, a = 8.4380(10) Å , c = 44.295(1) Å , 1809 independent reflections, 109 variables, R1 = 0.044, wR2 = 0.112).

The crystal structure represents a hybride built up from alternating layers (⟂ to the c-axis) of the NASICON structure-type and those showing the structure of silicophosphates M4[Si2O(PO4)6]. Isolated heteropolyanions [Si2O(PO4)6]12− and double-octahedra [InIIITiIVO9] occur as coordination polyhedra besides isolated octahedra [TiIVO6] and tetrahedral phosphate groups. The results of 29Si and 31P-MAS-NMR studies are in agreement with one crystallographically independent site for silicon and two sites for phosphorus. The phosphorus resonances can be related to the two sites by 2-dimensional cross-polarisation experiments, by the anisotropies of their chemical shifts, and by the observed line widths. All criteria lead to the same assignment. Substitution of In3+ by several trivalent transition metal ions leads to phosphate-silicophosphates M2Ti6(PO4)6[Si2O(PO4)6] (M = Ti3+, V3+, Cr3+, Fe3+)
Co2CrIn: A Further Magnetic Heusler Compound
Authors: Wurmehl Sabine , Fecher Gerhard H. , Felser Claudia
Published: February 2015

A further example of the class of Heusler compounds is presented. Co2CrIn is L21 ordered (face centered cubic, space group Fm3̅m) with a lattice constant of a = 6.0596(2) Å . The crystal structure was determined from powder diffraction data by means of the Rietveld method. The magnetic properties of Co2CrIn were measured by means of SQUID magnetometry. The material turns out to be a soft ferromagnet with a saturation moment of 1.2 μB at 5 K
Ein neuer Vertreter des A2B2CX4-Typs: Rb2Na2SiO4 / A New Member of the A2B2CX4-Type: Rb2Na2SiO4
Authors: Kerp Oliver , Möller Angela
Published: February 2015

Na2Rb2SiO4 crystallizes in a hitherto unknown A2B2CX4 type of structure. The ortho-silicate anions and sodium cations form a three-dimensional structure of connected tetrahedral and trigonalbipyramidal units. The larger rubidium cations complement the cationic part of the structure and display the motif of corrugated hexagonal layers with Rb-Rb distances of less than 400 pm. Single crystal structure data (space group Pbca, Z = 8, a = 983.20(7), b = 1092.26(6), c = 1113.04(8) pm) are given and a comparison to other A2B2CX4-type of structures is presented.
Aluminum and Gallium Hydrazides Derived from N-Aminopyrrole and N-Aminopiperidine
Authors: Uhl Werner , Vogelpohl Andreas , Kösters Jutta
Published: February 2015

The heterocyclic hydrazine derivatives N-aminopyrrole, H2N-NC4H4, and N-aminopiperidine, H2N-NC5H10, reacted with the hydrides H-Al(CMe3)2 or GaH3NMe2Et by the release of elemental hydrogen and the formation of the corresponding aluminum and gallium hydrazides. These products are dimerized in the solid state via Al-N-Al or Ga-N-Ga bridges and possess four-membered E2N2 heterocycles with two exocyclic N-N bonds.
Synthesis, Structure and Reactivity of the Molybdenum Cycloheptatrienyl Tetrahydroborate Complex {(η7-C7H7)Mo(η2-BH4)[P(cyclo-C6H11)3]}
Authors: Tamm Matthias , Dreßel Bernd , Bannenberg Thomas , Grunenberg Jörg , Herdtweck Eberhardt
Published: February 2015

The reaction of the cycloheptatrienyl-toluene sandwich complex [(η7-C7H7)Mo(η6- C6H5Me)]BF4 with tricyclohexylphosphine in acetonitrile furnishes the cationic half-sandwich cycloheptatrienyl complex {(η7-C7H7)Mo[P(C6H11)3](CH3CN)2}BF4 (1). Treatment of 1 with NaBH4 in ethanol results in the formation of the tetrahydroborate complex {(η7-C7H7)Mo(η2- BH4)[P(cyclo-C6H11)3]} (2), in which the borohydride ligand is coordinated to the molybdenum atom through two three-center, two-electron bonds. The complex is stable in ethanol and water. The expected formation of a metal trihydride of the type {(η7-C7H7)MoH3[P(cyclo-C6H11)3]} as a hydrolysis product could not be observed. Since this behaviour differs from the reactivity reported for related cyclopentadienyl-ruthenium complexes, a comparative computational study on the model complexes [(η5-C5Me5)RuH3(PMe3)] (4) and [(η7-C7H7)MoH3(PMe3)] (5) was performed revealing that the classical trihydride form [MH3] represents the global minimum for the ruthenium complex 4, whereas the dihydrogen-hydride form [MH(η2-H2)] is more stable for the molybdenum counterpart.
Ionic Conductivity of Gd- and Y-Doped Ceria-Zirconia Solid Solutions
Authors: Rührup Vera , Wiemhöfer Hans-Dieter
Published: February 2015

The total conductivity of the solid solutions (Ce1−xZrx)0.8Gd0.2O1.9 and (Ce1−xZrx)0.8Y0.2O1.9 was measured in air as a function of temperature (T = 300 °C- 600 °C) and composition (x = 0.0 - 0.9). A deep minimum of the bulk ionic conductivity was found for equal fractions of ceria and zirconia. It indicates enhanced defect association and ordering of the oxygen vacancies around x = 0.5. X-ray analysis (Guinier technique) showed the diffraction pattern of the cubic fluorite structure for all investigated compositions 0 < x < 1. The lattice parameter decreased linearly with increasing zirconia content x.
Untersuchungen Über Iodomercurate: Kristallstrukturen Von Bis-Tetramethylammonium-Tetraiodomercurat(Ii), Tetramethylammoniumpentaiododimercurat(Ii) Und Bis[Di(12-Krone-4)Lithium]-Decaiodotetramercurat(Ii)
Authors: Pickardt Joachim , Wiese Sven , Borowski Marina
Published: February 2015

Crystals of [Me4N]2[HgI4] (1) and [Me4N][Hg2I5] (2), were obtained from solutions of stoichiometric amounts of HgI2 and Me4NI in EtOH or acetone, resp., while crystals of [Li(12-crown- 4)2]2[Hg4I10] (3) formed upon interdiffusion of methanolic solutions of HgI2, LiI and of the auxiliary ligand. The crystal structures of the compounds were determined. The [Hg2I5]− ion in (2) has a polymeric sheet structure, built up from [Hg2I6] units bridged by [HgI4] groups sharing common apices. The [Hg4I10]2− ion in 3 consists of four [HgI4] tetrahedra sharing common edges. A short survey on the iodomercurate(II) anions known up to now is given and a classification is proposed
The Structure And Tautomerism Of Cyameluric Acid*
Authors: Wagler Jörg , El-Gamel Nadia E. A. , Kroke Edwin
Published: February 2015

The single crystal X-ray structure of the DMSO solvate of cyameluric acid C6N7O3H3 ·3DMSO, 2b’ has been determined. The results show that the most stable tautomer of solid cyameluric acid is the tri-keto form 2b with C3h symmetry. 1H and 13C NMR data indicate that this isomer is also present in solution, with slow interchange of the N-H protons. This confirms previous theoretical results although almost all derivatives reported in the literature are derivatives of the tri-hydroxy tautomer 2a
Preparation And Characterization Of Some Nickel 1,2-Dithiolene Complexes As Single-Component Semiconductors
Authors: Anyfantis G. C. , Papavassiliou G. C. , Terzis A. , Raptopoulou C. P. , Weng Y.F. , Yoshino H. , Murata K.
Published: February 2015

The unsymmetrical (mixed-ligand) nickel 1,2-dithiolene complexes Ni(pddt)(dmio) and Ni(pddt)(dmit) (where pddt is 6,7-dihydro-5H-1,4-dithiepin-2,3-dithiolate, dmio is 1,3-dithiol-2-one- 4,5-dithiolate, and dmit is 1,3-dithiol-2-thione-4,5-dithiolate) were synthesized and characterized. The new complexes were found to be soluble in organic solvents, from which single crystals and/or thin deposits can be obtained. In the solid state, the compounds behave as single-component semiconductors with low room temperature conductivity values
Structure Refinements Of REAuSn (Re = Sm, Gd, Tm)
Authors: Sebastian C. P. , Pöttgen Rainer
Published: February 2015

Well-shaped single crystals of the stannides REAuSn (RE = Sm, Gd, Tm) were obtained from arc-melted ingots. The samples were investigated on the basis of X-ray powder and single crystal data: NdPtSb type, P63mc, Z = 2, a = 467.3(1), c = 748.9(2) pm, wR2 = 0.0468, BASF = 0.273(14), 273 F2 values, 12 variables for SmAuSn, a = 465.14(9), c = 742.4(1) pm, wR2 = 0.0686, 265 F2 values, 11 variables for GdAuSn, and MgAgAs type, F4̅3m, Z = 4, a = 658.54(9) pm, wR2 = 0.0384, 120 F2 values, 5 variables for TmAuSn. The [AuSn] networks in SmAuSn and GdAuSn are two-dimensional with intralayer Au-Sn distances of 278 and 277 pm in the slightly puckered Au3Sn3 hexagons, respectively. The interlayer Au-Sn distances of 308 and 302 pm are much longer. TmAuSn has a network of corner-sharing AuSn4/4 tetrahedra with Au-Sn distances of 285 pm. The thulium atoms fill octahedral sites formed by the tin atoms. The crystal chemistry of these REAuSn stannides is briefly discussed
Ethene-trans-1,2-bis(4-pyridinium) Dihydrogenphosphite and Dihydrogenphosphate Compounds Exhibiting Cooperative and Directed Hydrogen Bonds between Cations and Anions: H2bpe(H2PO3)2 and H2bpe(H2PO4)2 · H2O
Authors: Yilmaz Veysel T. , Demir Selcuk , Harrison William T. A.
Published: February 2015

H2bpe(H2PO3)2 (1) and H2bpe(H2PO4)2 ・H2O (2) (H2bpe = ethene-trans-1,2-bis(4-pyridinium), H2PO3 = dihydrogenphosphite, and H2PO4 = dihydrogenphosphate) have been prepared and structurally characterized. In compound 1, the dihydrogenphosphite anions form dimers, with a P···P distance of 4.2073(7) Å , by two O-H···H hydrogen bonds, and the dimeric dihydrogenphosphite units interact with the H2bpe cations by way of N-H···O and O-H···O hydrogen bonds, resulting in a one-dimensional chain. The chains are held together by C-H···O interactions. In compound 2, the phosphate ions are connected by O-H···O hydrogen bonds into an unusual 2D square gridtype framework with P···P separations ranging from 4.7533(7) to 4.9506(8) Å . The H2bpe cations crosslink the dihydrogen phosphate layers by N-H···O hydrogen bonds, forming a three-dimensional supramolecular network with channels. The water molecules in compound 2 occupy these channels and make O-H···O bonds to adjacent phosphate O atoms and also O-H···O bonds to the next water O atom in the channel.
Syntheses, Spectral and Thermal Studies, and Crystal Structure of 1,10-Phenanthroline and Picolinamide Complexes of Cobalt(II) Squarate
Authors: Yeşilel Okan Zafer , Ölmez Halis , Yılan O. Ozan , Paşaoğlu Hümeyra , Büyükgüngör Orhan
Published: February 2015

Preparations, crystal structures, thermal properties, IR and UV/vis spectroscopic studies and magnetic moments of tris(1,10-phenanthroline)cobalt(II) squarate octahydrate, [Co(phen)3]sq ・ 8H2O (1) and diaquabis(picolinamide)cobalt(II) squarate, [Co(H2O)2(pia)2]sq (2) are described. 1 crystallizes in the monoclinic system, space group P21/c, with a = 10.9832(5), b = 21.4569(12), c = 17.0649(7) Å , β = 98.159(3)° and Z = 8, while 2 crystallizes in the triclinic system, space group P1̅, with a =6.9624(9), b =7.9224(11), c =8.0501(11)Å ,α =107.404°, β =93.340(11)°, γ =93.266° and Z = 1. Both 1 and 2 have slightly distorted octahedral coordination geometry, involving six N atoms from bidentately chelating phen ligands and trans-[CoN2O4] coordination geometry, in which the Co atom is located at a center of symmetry. There are significant hydrogen-bonding interactions in the structure of 1. The squarate dianions are linked to the eight solvent water molecules by means of hydrogen-bonding interactions. Moreover, there are links between the complex cation and the squarate dianion via C-H···O hydrogen bonds. These interactions hold the crystal structure of 1 in a three-dimensional network, while O-H···O, N-H···O, weak π ···π and π ··· ring interactions lead to a three-dimensional crystal structure for 2. The thermal decomposition pathways of 1 and 2 have been investigated by the help of thermal analyses data (TG and DTA).
Phase Transitions Mechanism and Distortion of SbCl6
3– Octahedra in Bis(n-butylammonium) Pentachloroantimonate(III) (C4H9NH3)2[SbCl5]
Authors: Zarychta Bartosz , Zaleski Jacek
Published: February 2015

Bis(n-butylammonium) pentachloroantimonate(III) was obtained in a reaction of n-butylammonium chloride and antimony trichloride (molar ratio 2 : 1; cation : Sb) in acidic aqueous solution. To obtain further information about the mechanism of the earlier reported phase transitions at 229 and 315 K the structure was determined at 100, 260 and 340 K. The orthorhombic system was found in all phases, space groups Ibam at 340 K and Pccn at 260 and 100 K. In all phases the anionic sublattice consists of [SbCl6]3− octahedra, connected via cis chlorine atoms, forming onedimensional zig-zag {[SbCl5]2−}n chains extended along the c direction. The n-butylammonium cations are located between the inorganic chains, with -NH3
+ groups facing the oppositely charged polyanions. The phase transitions are of the order-disorder type. They are related to changes in molecular dynamics of the n-butylammonium cations. At high temperature the cations reorient, on decreasing temperature the reorientations are successfully frozen. This leads to the formation on N-H. . .Cl hydrogen bonds, which significantly deform the octahedral coordination of the Sb atoms.
Paullinoside A and Paullinomide A: A New Cerebroside and a New Ceramide from Leaves of Paullinia pinnata
Authors: Miemanang Rénadin Siagat , Krohn Karsten , Hussain Hidayat , Dongo Etienne
Published: February 2015

Paullinoside A (1a), a new cerebroside, and a new ceramide named paullinomide A (2a), have been isolated from Paullinia pinnata. Their structures were determined by comprehensive analyses of their 1D and 2D NMR, HREIMS spectral data, and chemical evidence. The remaining four known compounds were identified as β -amyrin, 13β ,17β -dihydroxy-28-norolean-12-ene, β -sitosterol, and β -sitosterol glucopyranoside.
Synthesis and X-Ray Single Crystal Structure of Dialkyl 2-[1-(2,2-Dimethylpropionyl)-3,3-dimethyl-2-oxobutyl]-3- (triphenylphosphoranylidene)succinates
Authors: Ramazani Ali , Kazemizadeh Ali Reza , Ahmadi Ebrahim , Ślepokura Katarzyna , Lis Tadeusz
Published: February 2015

A one-pot synthesis of sterically congested phosphorus ylides in fairly high yields by the reaction of 2,2,6,6-tetramethyl-3,5-heptanedione, dialkyl acetylenedicarboxylates and triphenylphosphine is reported. The structures of these compounds were confirmed by IR, 1H, 31P and 13C NMR spectroscopy, and X-ray single crystal structure determination. The NMR spectra (CDCl3 as solvent) indicated that the compounds contained two rotamers for each ylide.
Two Prenylated Flavones from the Tree Bark of Artocarpus lanceifolius
Authors: Syah Yana M. , Achmad Sjamsul A. , Aimi Norio , Hakim Euis H. , Juliawatya Lia D. , Takayama Hiromitsu
Published: February 2015

Two new prenylated flavones, artoindonesianins Z-1 (1) and Z-2 (2), together with two other known prenylated flavones, artobiloxantone (3) and cycloartobiloxanthone (4), had been isolated and identified from the chloroform extract of the tree bark of Artocarpus lanceifolius. The structures of these compounds were determined based on spectroscopic data, including UV, IR, 1-D and 2-D NMR, and mass spectra. The significance of the presence of the isolated compounds to the chemotaxonomy of Artocarpus is briefly discussed.
Synthesis of Some 2-Aminonitroethanes via Silica Gel-Catalyzed Nitro-Mannich Reaction
Authors: Mahasneh Ali S.
Published: February 2015

A direct one pot, three-component nitro-Mannich reaction of a nonenolizable aldehyde, aniline or one of its ring-substituted derivatives and nitromethane was carried out on silica gel surface. The products of the reaction, 2-aminonitroethane, were obtained in high yields. IR, 1H NMR, 13C NMR spectra and elemental analysis confirmed the structures of the products.
The Reactions of Some Alkyl(thio)-Substituted 2-Nitrodienes with Piperazines and a Structural Study
Authors: Ibis Cemil , Sayil Cigdem , Ozkok Funda
Published: February 2015

Thiosubstituted nitrodiene compound 1a was obtained from 2-nitropentachlorobutadiene and dodecanethiol. Compound 1b was prepared from 2-nitropentachlorobutadiene and hexadecanethiol. Monosubstituted diene compounds 1a and 1b reacted with piperazines such as derivatives of 2 and 4 in CH2Cl2 and gave the novel compounds. 2-Nitro-3,4,4-trichloro-1-dodecylthio-1-(2-fluorophenylpiperazinyl]- 1,3-butadiene (3d) was synthesized and its crystal structure was determined.
Acylated Iridoid Glycosides from the Flowers of Verbascum lasianthum Boiss. ex Bentham
Authors: Tatli I. Irem , Khan Ikhlas A. , Akdemir Zeliha S.
Published: February 2015

Two new (1 - 2) and five known iridoid glycosides (3 - 7) as well as a known saponin (8) were isolated from the flowers of Verbascum lasianthum and their structures were determined as 6-O-(4"-O-trans-p-coumaroyl)-α-L-rhamnopyranosylaucubin (1), 6-O-(4"-O-trans-p-methoxycinnamoyl)- α-L-rhamnopyranosylaucubin (2), sinuatol (3), aucubin (4), geniposidic acid (5), catalpol (6), ajugol (7) and ilwensisaponin A (8) on the basis of 1D and 2D NMR spectral analysis.
A Short Novel Synthesis of the Phosphazene Base Et-P2
Authors: Schwesinger Reinhard , Dambacher Tim
Published: February 2015

A novel synthesis of the phosphazene base Et-P2 is presented, which approximately halves the efforts of its production.
Novel Selective 5-HT3 Receptor Ligands: Facile Generation Methods for 2-Amino- and 4-Aminopyrido[4’,3’:4,5]thieno[2,3-d]pyrimidines
Authors: Ameen Mohamed A.
Published: February 2015

This work reports on the synthesis of new 2-amino- and 4-aminopyridothienopyrimidines, with a view to identify potent and selective ligands for the 5-HT3 receptor, starting from derivatives of 2-aminothiophene-3-carboxylic ester, -3-carboxamide, or 2-amino-3-cyanothiophene.
Amidrazones in the Synthesis of 1H-1,2,4-Triazoles
Authors: Aly Ashraf A. , Gomaa Moshen A.-M. , El-Din Ahmed M. Nour , Fahmi Magda S.
Published: February 2015

The syntheses of various 2-(4-aryl-2,4-dihydro-3-phenyl-1,2,4-triazol-3-ylidene)indan-1,3-diones are reported. The key to their successful synthesis depends on the reaction of amidrazones 1a - f with 2-(1,3-dioxoindan-2-ylidene)malononitrile (2).
Supramolecular Organization of Organoammonium Squarates
Authors: Yeşilel Okan Zafer , Odabaşoǧlu Mustafa , Ölmez Halis , Büyükgüngör Orhan
Published: February 2015

Syntheses, thermal behavior, and IR data of three hydrogen squarates, Hsq−, with 2-(acetylamino)- 4-methylpyridinium, [(C8H11N2O)(HC4O4)] (1), 2-carboxamido-pyridinium, [(C6H7N2O)- (HC4O4)] (2), and 2-methylpyridinium cations, [(C6H8N)(HC4O4)(H2O)] (3), and one squarate, sq2−, with 2-amino-4-methyl-pyrimidinium cations, [(C6H9N2)2(C4O4)] (4) are reported. The crystal structures of 1 and 4 have been studied. The compounds decompose in two thermal stages: (i) release of organic base, (ii) decomposition of squarate. Crystallographic analyses show that 1 and 4 have S6, R2
2(10) R2
2(9) R2
2(7) rings. The hydrogen bonding motifs formed by the hydrogensquarate anions interact with the ammonium cations through N−H ··· O hydrogen bonds and give rise to predominantly layered structures, which also exhibit three-dimensional connectivity.
Substituent and Solvent Effects on the Electrochemical Oxidation of para- and meta-Substituted Anilines
Authors: Bhuvaneshwari Durvas S. , Elango Kuppanagounder P.
Published: February 2015

Electrochemical oxidation of fifteen para- and meta-substituted anilines in different mole fractions of acetic acid in water has been investigated in the presence of 0.1 M sulphuric acid as supporting electrolyte. The oxidation potential data of anilines correlates well with Hammett’s and Brown- Okamoto’s substituent constants affording negative reaction constants. The effect of para- and metasubstituents on the oxidation potential conforms to Swain’s F and R parameters, affording negative reaction constants. The oxidation potential values correlate well with macroscopic solvent parameters such as relative permittivity, εr, and polarity, ET
N. Multiple correlation analysis also shows an excellent correlation with the oxidation potential values.
Two New Oleanane Triterpene Glycosides from the Bark of Terminalia arjuna
Authors: Ali Asif , Ali Mohammed , Alam Mohd S.
Published: February 2015

Two new oleanane triterpene glycosides designated as termiarjunoside I (1) and termiarjunoside II (2), isolated from the bark of Terminalia arjuna (Combretaceae), have been characterized as olean- 1α,3β ,9α,22α-tetraol-12-en-28-oicacid-3β -D-glucopyranoside (1) and olean-3α,5α,25-triol-12-en- 23,28-dioic acid-3β -D-glucopyranoside (2), respectively, on the basis of chemical and spectral data evidences.
Oligomeric Supersandwich Structure of a Lithium Enamino- Cyclopentadienide
Authors: Kotov Vasily V. , Kehr Gerald , Fröhlich Roland , Erker Gerhard
Published: February 2015

Deprotonation of 6-methyl-6-dimethylaminofulvene with a lithium amide base gave lithium (1-dimethylamino-ethenyl)cyclopentadienide. In the crystal it features a close to perfect oligomeric supersandwich structure. In contrast to related (aminomethyl-Cp)Li complexes here the enamino substituent is not directly involved in the formation of the oligomeric suprastructure.
Synthesis of Novel Macrocyclic Peptido-calix[4]arenes and Peptidopyridines as Precursors for Potential Molecular Metallacages, Chemosensors and Biologically Active Candidates
Authors: El-Sayed Amr Abd El-Galil , Abo-Ghalia Mohamed , Abdalah Mohamed M.
Published: February 2015

Novel macrocyclic dipicolinic acid acylated peptides based on upper rim bridged peptidocalix[ 4]arenes, peptido-pyridines or hybrid structures of both, were synthesized as potential molecular metallacages and chemosensors. While conventional azide or mixed anhydride (ethyl chloroformate) peptide couplings served well for assembling the L-tyrosine or L-ornithine peptide backbones, the acid chloride of pyridine-2,6-dicarboxylic acid (dipicolinic acid) acid served as the complementary acylating agent. The structure assignment of the new compounds was based on chemical and spectroscopic evidences. Some of these compounds exhibit antimicrobial activities.
Kinetics of the Oxidation of L-Cysteine by trans- and cis-Cobalt(III) and Iron(III) Complexes
Authors: Abdel-Halim Hamzeh M. , Abu-Surrah Adnan S. , Baker Hutaf M.
Published: February 2015

Kinetics of oxidation of L-cysteine by pairs of trans and racemic cis isomers of cobalt(III) and iron(III) based transition metal complexes have been studied in aqueous solution. Kinetics measurements were run under pseudo first order conditions in which the concentration of cysteine is between one and two orders of magnitude greater than that of the isomers of the transition metal complex. The orders of the reaction with respect to both cysteine and the isomer were determined.

The observed rate constants and the overall rate constants of the oxidation process were measured. For all geometrical isomers, it was found that the rate constant of oxidation of L-cysteine by the trans isomer is between one to three orders of magnitude greater than that by the cis isomer. The difference in rates can be explained by a geometric factor around the metal ion center in the complex. The less crowded isomer (trans) makes electron transfer easier and hence facilitates the oxidation process which leads to a higher oxidation rate.
Secondary Interactions in Gold(I) Complexes with Thione Ligands, 4. Three Further Salts of the Bis(imidazolidine-2-thione)gold(I) Cation [1, 2]
Authors: Friedrichs Steffi , Jones Peter G.
Published: February 2015

Three structures of the form bis(imidazolidine-2-thione)gold(I) disulfonylamide [disulfonylamide = benzene-1,2-di(sulfonyl)amide (1), di(4-chlorobenzenesulfonyl)amide (2), di(4-iodobenzenesulfonyl) amide (3)] were determined. Compound 3 crystallizes with four independent formula units. The cations in 1 and 3 show an antiperiplanar conformation about the S···S axis, whereas the corresponding torsion angle in 2 is 72°. The packing in 1 consists of linked ribbons in which the NH groups of neighbouring cations are bridged by O-S-O groups of the anions. Compound 2 exhibits a complex layer structure in which several multi-centre hydrogen bonds are observed. The structural subunits of compound 3 involve an alternating anion-cation chain for two of the cations and inversionsymmetric anion-cation dimers for the other two cations. Short C-H···Au contacts (shortest H···Au 2.63 Å in 2) contribute to the packing of compounds 2 and 3.
Syntheses of Allyl- and 3-Silylpropyl-substituted Salen-like Tetradentate Ligands via Hypercoordinate Silicon Complexes
Authors: Wagler Jörg , Roewer Gerhard
Published: February 2015

The reaction of allylchlorosilanes (AllSiCl3, AllSiPhCl2) with the tetradentate salen-like ligand 1, o-HO-p-MeO-C6H3-C(Ph)=N-(CH2)2-N=C(Ph)-C6H3-p-OMe-o-OH, yields pentacoordinate silicon complexes of an allyl-substituted ligand system (o-O-p-MeO-C6H3-C(Ph)=N-(CH2)2- N-C(Ph,All)-C6H3-p-OMe-o-O)SiR (2a: R = Ph, 3: R = Cl). The allyl shift step involved in the formation of 2a and 3 probably occurs via an intermediate hexacoordinate silicon complex. This reaction is diastereoselective. The missing diastereomer of 2 (2b) was prepared using an alternative synthesis route, which starts from the trimethylsilyl derivative of ligand 1 o-Me3SiO-p-MeO-C6H3-C(Ph)=N- (CH2)2-N=C(Ph)-C6H3-p-OMe-o-OSiMe3. The diastereomers of 2 obtained from modified reaction pathways give rise to suggestions about the mechanism of formation of these complexes.

Further functionalization of the allyl-substituted ligand system of 3 was carried out by hydrosilylation with HSiCl3 to yield complex 4 (o-O-p-MeO-C6H3-C(Ph)=N-(CH2)2-N-C(Ph)[(CH2)3-SiCl3]- C6H3-p-OMe-o-O)SiCl.
Copolymerization of Ethylene/Diene with Different Metallocene Catalysts
Authors: Vieira Marques Maria de Fátima , Rocha Fernanda Constantino , Soto Narda Juárez
Published: February 2015

Copolymerizations of ethylene and 1,7-octadiene were carried out employing homogeneous catalysts Cp2ZrCl2, Ph2C(Flu,Cp)ZrCl2 and Et(Ind)2ZrCl2, and methylaluminoxane as cocatalyst. The polymerization characteristics, such as catalytic activity, polymerization rate, copolymer composition, and thermal properties were examined in relation to the catalyst type. Different comonomer concentrations were employed, and the reaction time was varied, ranging from 1 h up to 4 h, at 90°C and at 0.5 bar ethylene pressure. The results showed that the catalyst Cp2ZrCl2 was more efficient than Et(Ind)2ZrCl2 in the preparation of high diene content ethylene/1,7-octadiene copolymers. On the other hand, Et(Ind)2ZrCl2 and Ph2C(Flu,Cp)2ZrCl2 catalysts produced low insaturation content but possibly formed cyclic structures and crosslinking.
Alkaloids from Palicourea coriacea (Cham.) K. Schum.
Authors: do Nascimento Claudia A. , Gomes Mislene S. , Lião Luciano M. , de Oliveira Cecília M. A. , Kato Lucilia , da Silva Cleuza C. , Tanaka Clara M. A.
Published: February 2015

Two new β -carboline alkaloids, epi-strictosidinic acid (1) and strictosidinic ketone (2), together with two known alkaloids, calycanthine (3) and strictosidinic acid (4) besides the triterpene ursolic acid (5) were isolated from the roots and leaves of Palicourea coriacea. The structures of the isolates were elucidated on the basis of spectral data, particularly COSY, HMQC and HMBC experiments, and HR mass spectra.
Synthesis, Structure and Properties of the High-pressure Modifications of the Ternary Compounds REPtSn (RE = La, Pr, Sm)
Authors: Riecken Jan F. , Rodewald Ute Ch. , Heymann Gunter , Rayaprol Sudhindra , Huppertz Hubert , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: February 2015

The hexagonal high-pressure (HP) modifications of the ternary compounds REPtSn (RE = La, Pr, Sm) were prepared under multianvil high-pressure (9 - 14 GPa) high-temperature (1050 - 1400 °C) conditions from the orthorhombic normal-pressure (NP) modifications. The HP-REPtSn stannides were investigated by X-ray diffraction on powders and single crystals: ZrNiAl type, space group P6̅2m, a = 762.6(2), c = 418.55(7) pm, wR2 = 0.1147, 256 F2 values and 14 variables for HP-LaPtSn, a = 754.97(7), c = 412.64(3) pm, wR2 = 0.0782, 252 F2 values and 14 variables for HP-PrPtSn, and a = 750.1(2), c = 407.6(1) pm, wR2 = 0.1060, 229 F2 values and 14 variables for HP-SmPtSn. The high-pressure modifications have two crystallographically independent platinum positions in trigonal prismatic coordination, Pt1Sn6RE3 and Pt2Sn3RE6. The shortest interatomic distances occur between the platinum and tin atoms with in the three-dimensional [PtSn] networks. The rare earth atoms fill distorted hexagonal channels within these networks and they are bound through short RE-Pt contacts. Susceptibility measurements of HP-PrPtSn reveal paramagnetic behaviour with an experimental magnetic moment of 3.31(2) μB/Pr atom. Low-temperature susceptibility and specific heat data point to inhomogeneous magnetism in HP-PrPtSn.
Superhard Superconductor Composites Obtained by Sintering of Diamond, c-BN and C60 Powders with Superconductors
Authors: Dubitsky Gennadi A. , Blank Vladimir D. , Buga Sergei G. , Semenova Elena E. , Serebryanaya Nadejda R. , Aksenenkov Vladimir V. , Prokhorov Vyatcheslav M. , Kul’bachinski Vladimir A. , Krechetov Aleksei V. , Kytin Vladimir G.
Published: February 2015

Superhard superconducting samples with a critical temperature of TC = 10.5 - 12.6 K were obtained by high-pressure / high-temperature sintering of synthetic diamond powders coated with a niobium film and in 50% - 50% composition with superhard C60 fullerene. Superhard superconductors with TC = 9.3 K were obtained when diamond and molybdenum powders were sintered at a pressure of 7.7 GPa and a temperature of 2173 K. Superconducting samples with TC = 36.1 - 37.5 K have been obtained in the systems diamond-MgB2 and cubic boron nitride-MgB2.
High-pressure / High-temperature Synthesis and Characterization of Boron-doped Diamond
Authors: Dubrovinskaia Natalia , Dubrovinsky Leonid , Miyajima Nobuyoshi , Langenhorst Falko , Crichton Wilson A. , Braun Hans F.
Published: February 2015

Bulk samples (with volumes up to ~ 7.5 mm3) of boron-doped diamonds (BDD) were synthesized by means of direct reaction between boron carbide and graphite in a multianvil apparatus at high pressures and high temperatures (HPHT). X-ray diffraction data revealed the presence in BDD of a very small amount of a highly boron-enriched phase (B50C2) and traces of the B13C2 used as an initial material. The absence of B50C2 in the product of treatment of pure B13C2 under the same HPHT conditions suggests that boron-rich carbides exsolute from diamond on quenching leading to boron depletion of the diamond matrix. These observations imply that boron solubility in diamond increases at high pressure and high temperature. This result may have important implications for the understanding of the mechanism of boron incorporation into diamond at HPHT synthesis and for the interpretation of the data on superconductivity of polycrystalline BDD.
Synthesis and Crystal Structure of K6Mo10O33
Authors: Arumugam Nachiappan , Peters Eva-Maria , Jansen Martin
Published: February 2015

A new potassium molybdenum oxide, K6Mo10O33, was synthesized by solid state reaction from the appropriate quantities of pre-dried MoO3 and K2MoO4, fired at around 650 °C for 2 d. The structure has been solved by using single crystal X-ray diffraction. The compound adopts the space group P1, with the lattice constants a = 7.7100(5), b = 11.9659(8), c = 17.1321(12) A° , α = 86.42 (10), β = 77.18(10), γ = 74.14(10)°. The structure is built up of infinite chains of edge-sharing MoO6 octahedra and groups of four MoO6 octahedra forming Mo4O17 units. These sub-units are connected together by common vertices.
Syntheses and Crystal Structures of the New Ternary Barium Halide Hydrides Ba2H3X (X = Cl or Br)
Authors: Reckeweg Olaf , Molstad Jay C. , Levy Scott , DiSalvo Francis J.
Published: February 2015

Single crystals of the isotypic hydrides Ba2H3X (X = Cl or Br) were obtained by solid-state reactions of Ba, NaCl, NaNH2 and metallic Na, or Ba, NH4Br and Na, respectively, in sealed, silicajacketed stainless-steel ampoules. The crystal structures of the new compounds were determined by means of single crystal X-ray diffraction. Ba2H3Cl and Ba2H3Br crystallize in a stuffed anti CdI2 structure and adopt the space group P3̄m1 (No. 164) with the lattice parameters a = 443.00(6), c = 723.00(14) pm and a = 444.92(4), c = 754.48(14) pm, respectively. The hydride positions are derived by crystallographic reasoning and with the help of EUTAX calculations. The results are compared with known data for binary and ternary alkaline earth metal hydrides.
Alternativ-Liganden XXXVIII. [1] Neue Versuche zur Synthese von Pd(0)- und Pt(0)-Komplexen des Tripod-Phosphanliganden FSi(CH2CH2PMe2)3 / Alternative Ligands XXXVIII. [1] Further Attempts to Synthesize Pd(0) and Pt(0) Complexes with the Tripod Phosphane Ligand FSi(CH2CH2PMe2)3
Authors: Grobe Joseph , Lütke-Brochtrup Kai , Krebs Bernt , Läge Mechtild , Niemeyer Hans-Hermann , Würthwein Ernst-Ulrich
Published: February 2015

The tripod phosphane ligand FSi(CH2CH2PMe2)3 (1) has been prepared again and attempts to generate F3CSi(CH2CH2PMe2)3 (2) were undertaken for the preparation of transition metal cage compounds of the type A(CCP)3M or A(CCP)3M-L (A = FSi, F3CSi). The photochemical addition of dimethylphosphane to trifluoromethyl-trivinylsilane, however, gave 1 instead of the expected CF3Sitripod ligand 2, obviously due to difluorocarbene elimination. 1 was used to prepare the chromium carbonyl derivative (CO)3Cr[(Me2PCH2CH2)3SiF] (3) from Cr(CO)3CHT, and 3 was characterized by NMR and IR spectroscopy. The novel complex FSi(CH2CH2PMe2)3Pd (4) and its PPh3 derivative [FSi(CH2CH2PMe2)3Pd]PPh3 (5) have been obtained by reacting 1 with Pd(PPh3)4 and were characterized by NMR (4) and X-ray diffraction (5). The data prove the expected Pd→Si interaction by characteristic coordination shifts and a Pd-Si distance of 3.875 Å which is smaller than the Ni-Si distance in the corresponding nickel compound (3.92 Å ). The preparation of the analogous platinum complex from the precursors Pt(PPh3)4, Pt(C7H10)3, or (Ph3P)2Pt(η2-C2H4) failed, whereas the reaction of 1 with Pt(PEt3)4 was successful, but surprisingly led to the trinuclear complex [FSi(CH2CH2PMe2)3Pt]3(PMe2CH2CH2)3SiF (6) with three cages of type 4 and an additional ligand 1 as a bridging unit. Complex 6 was isolated and characterized spectroscopically. Quantum chemical calculations have been used to elucidate the coordination geometry expected for 4, 5 and the corresponding platinum cage 4′ in 6. The calculations support the structure of 5 within the expected limitations of the experimental and theoretical methods and - in spite of the extremely soft coordination sphere of the studied cages - are in accord with the spectroscopic results.
Ring Transformations of 1,2,4-Dithiazoles: Synthesis and Biological Studies of Novel S-Heterocycles, and Their Relevant Phosphono Derivatives
Authors: Abdou Wafaa M. , Khidre Maha D.
Published: February 2015

Reactions of 5-phenyl-3(3H)-thioxo-1,2,4-dithiazole (1) with unsaturated and active phosphonium salts as well as with phosphonates, at r. t. and under the effect of basic catalysis, afforded mainly 1,3,5- dithiazines 5, 12, 17a, 17b, 23a or 23b. Substituted 1,3-dithiol 7 and 1,3-thiazoles 13, 19a, 19b, 22a and 22b were isolated as by-products. 1,3,5-Dithiazine products showed pharmacological potency.
Convenient Selective Synthesis of Substituted Pyrido[2,3-d]pyrimidones and Annulated Derivatives
Authors: Hamama Wafaa S. , Ismail Mohamed A. , Al-Saman Hana’a A. , Zoorob Hanafi H.
Published: February 2015

The reaction of 6-aminouracil (1) with the appropriate α,β -unsaturated ketones, gave the corresponding pyrido[2,3-d]pyrimidin-2,4-diones 3, 6, 8 and 10, respectively. Treatment of 1 with salicylaldehyde, 6-carboethoxy-3,5-diphenyl-2-cyclohexenone (13) or 2,6- bis(phenylmethylidene)cyclohexanone (15) afforded the corresponding pyrimido[4,5-d]quinoline- 2,4-diones 12, 14 and 16, respectively. Furthermore, a pyrido[2,3-d]pyrimidine incorporating 3,2’- bis(quinoline) derivative 18 was synthesized. Annulation of pyrido[2,3-d]pyrimidine with pyrazole or imidazole moieties was achieved via reaction of 1 with benzylidene derivatives of pyrazolone, imidazolone or 3-carboethoxycoumarin (23) to give 21, 22 and 24, respectively.
Jasonone, a Nor-sesquiterepene from Jasonia montana
Authors: Mohamed Abou El-Hamd H.
Published: February 2015

A new natural nor-sesquiterpene was isolated from the leaves of Jasonia montana, in addition to another rare nor-sesquiterpene. Their structures were established by spectroscopic methods, including 1H, 13C, DEPT, 1H-1H COSY, HMQC, HMBC, NOESY, IR and HR-MS.
Calostomal, a Polyene Pigment from the Gasteromycete Calostoma cinnabarinum (Boletales)
Authors: Gruber Gertraud , Steglich Wolfgang
Published: February 2015

The North American stalked puffball Calostoma cinnabarinum (Boletales) owes its red-orange colour to the heptaene pigment calostomal. Its structure has been determined by 1H and 13C NMR spectroscopy of the corresponding methyl ester as all-trans-16-oxohexadeca-2,4,6,8,10,12,14- heptaenoic acid (1). Neither pulvinic acids nor other typical Boletales pigments could be detected in this fungus. The structural relationship of 1 to other polyene pigments from fungi is discussed.