bluuebunny/crossref_metadata_2025 huggingface dataset:
Kristallzucht und Strukturaufklärung von K2[Pt(CN)4Cl2], K2[Pt(CN)4Br2], K2[Pt(CN)4I2] und K2[Pt(CN)4Cl2] · 2H2O/ Crystal Growth and Crystal Structure Determination of K2[Pt(CN)4Cl2], K2[Pt(CN)4Br2], K2[Pt(CN)4I2] and K2[Pt(CN)4]Cl2] · 2H2O
Authors: Mühle Claus , Karpov Andrey , Nuss Jürgen , Jansen Martin
Published: August 2018

Crystals of K2Pt(CN)4Br2, K2Pt(CN)4I2 and K2Pt(CN)4Cl2 ·2H2O were grown, and their crystal structures have been determined from single crystal data. The structure of K2Pt(CN)4Cl2 has been determined and refined from X-ray powder data. All compounds crystallize monoclinicly (P21/c; Z = 2), and K2Pt(CN)4X2 with X = Cl, Br, I are isostructural. K2Pt(CN)4Cl2: a = 708.48(2); b = 903.28(3); c = 853.13(3) pm; β = 106.370(2)°; Rp = 0.064 (N(hkl) = 423). K2Pt(CN)4Br2: a = 716.0(1); b = 899.1(1); c = 867.9(1) pm; β = 106.85(1)°; R(F)N′ = 0.026 (N’(hkl) = 3757). K2Pt(CN)4I2: a = 724.8(1); b = 914.5(1); c = 892.1(1) pm; β = 107.56(1)°; R(F)N′ = 0.025 (N’(hkl) = 2197). K2Pt(CN)4Cl2 ·2H2O: a = 763.76(4); b = 1143.05(6); c = 789.06(4) pm; β = 105.18(1)°; R(F)N′ = 0.021 (N’(hkl) = 2281). Raman and infrared spectroscopy data are reported.
Enzyme Inhibiting Terpenoids from Amberboa ramosa
Authors: Khan Sher B. , Malik Abdul , Afza Nighat , Jahan Nusrat , Haq Azhar U. , Ahmed Zaheer , Nawaz Sarfraz A. , Choudhary Mohammed Iqbal
Published: August 2018

Two new cycloartane type triterpenes 1 and 2 have been isolated from Amberboa ramosa. Their structures were established as (22R)-cycloart-20, 25-dien-2α,3β ,22α-triol 1 and (22R)-cycloart-23- ene-3β ,22α, 25-triol 2 through spectroscopic studies including 2D-NMR. The known compounds 3,4-epoxyguaia-1(10), 11(13)-dien-6, 12-olide 3, and 5-hydroxy 7,8,2’,3’-tetramethoxyflavone 4 are also reported for the first time from this species. The compounds 1 and 2 displayed inhibitory potential against butyrylcholinesterase.
Oxotellurate(IV) der Lanthanide: I. Die isotype Reihe M2Te4O11 (M = La – Nd, Sm – Yb)
Authors: Meier Steffen F. , Schleid Thomas
Published: August 2018

The present work is the first comprehensive account of the knowledge acquired from single crystals of the isotopic series M2Te4O11 (M = La - Nd, Sm - Yb). In the crystal structure, the M3+ cation is coordinated by eight oxygen atoms in the shape of a distorted square antiprism. Out of these polyhedra a mesh-like [M2O16]14− layer parallel to the (001) plane is built via three common edges. The [Te4O11]6− double layers in turn build two tellurium-oxygen chains crosswise to each other. The construction of the tellurium-oxygen partial structure is, however, only possible taking the secondary Te-O contacts into consideration. In most oxotellurates(IV), three oxygen atoms are covalently bound to the Te atoms (d(Te-O) ≈ 180−200 pm; ψ1 tetrahedron). Another oxygen atom is found in the near vicinity at a distance of 230 to 280 pm. The significance of such secondary interactions for the stability of the crystal structures was recognized recently in theoretical as well as experimental investigations. All oxygen atoms with distances smaller than 280 pm are counted to the secondary coordination sphere. This limit may seem somewhat arbitrary but it accounts very well for the Te-O partial structure. The coordination sphere for the tellurium center is a ψ1 trigonal bipyramid including the stereochemically active electron pair (“lone pair”). A description of the crystal structure is also possible without this partial structure, however in the [TeO3+1]4− polyhedra above and below the meshes of [M2O10]14− layers are linked via Te2-O6-Te2 contacts only.
Isolation, Characterization and Crystal Structure of Natural Eremophilenolide from Ligularia sagitta
Authors: Li Lyi , Xu Li-Wen , Jiang Yan-Feng , Xi Chan-Juan , Wang Han-Qing , Suo You-Rui
Published: August 2018

A new eremophilenolide 1β ,10β -epoxy-6β -acetoxy-3β -angeloyloxy-8β -hydrox y-eremophil- 7(11)-en-8,12α-olide (1), together with liguhodgsonal (2), esculetin (3) and β -sitosterol (4), was isolated from the aerial parts of Ligularia sagitta. The structure of the new constituent (1) was elucidated by spectroscopic methods and confirmed by single-crystal X-ray diffraction.
Low Dimensional Materials: Syntheses, Structures, and Optical Properties of Rb2CuTaS4, Rb2CuTaSe4, RbCu2TaSe4, K3Ag3Ta2Se8, and Rb3AgTa2Se12
Authors: Wu Yuandong , Näther Christian , Bensch Wolfgang
Published: August 2018

The new compounds Rb2CuTaS4 (1), Rb2CuTaSe4 (2), RbCu2TaSe4 (3), K3Ag3Ta2Se8 (4), and Rb3AgTa2Se12 (5) have been synthesized by the reactive flux method at 773 or 873 K. Their crystal structures were determined by single crystal X-ray diffraction. Crystal data for 1: space group Fddd, a = 5.598(1), b = 13.512(4), c = 23.854(5) Å , Z = 8; Crystal data for 2: space group Fddd, a = 5.782(1), b = 13.924(3), c = 24.653(5) Å , Z = 8; Crystal data for 3: space group C2cm, a = 5.7218(3), b = 19.2463(13), c = 7.7456(5) Å , Z = 4; Crystal data for 4: space group C2/c, a = 25.1374(19), b = 6.1007(3), c = 14.4030(11) Å , β = 119.703(8)◦, Z = 4; Crystal data for 5: space group P21/n, a = 9.8186(6), b = 13.7462(11), c = 15.7368(9) Å , β = 96.681(7)◦, Z = 4. The compounds 1 and 2 are built up of 1
∞[CuTaQ4]2− anionic chains which are formed by edge-sharing CuQ4 and TaQ4 tetrahedra. The rubidium cations are located between the chains. Compound 3 consists of 2
∞[Cu2TaSe4]− anionic layers separated by rubidium cations. The anionic layers are formed by1
∞[CuTaSe4]2− chains which are connected by CuSe4 tetrahedra that share common edges with the TaSe4 tetrahedra of neighboring chains. In compound 4 1
∞[Ag3Ta2Se8]3− anionic chains are found which are separated by potassium cations. These chains are formed by successive corner sharing of AgSe4 tetrahedra and edge sharing between AgSe4 and TaSe4 tetrahedra. All three structures are closely related with the sulvanite (Cu3VS4) structure type. Compound 5 contains a one dimensional 1
∞[AgTa2Se12]3− anionic chain formed by interconnection of AgSe4 tetrahedra and [Ta2Se11] units. In the structure three monoselenide, three diselenide, and one triselenide anions are found. Raman and far-IR spectroscopic data of compounds 1 and 4 were collected and an interpretation is presented.
Pyrrole Thioaldehyde Complexes of Nickel, Palladium and Platinum
Authors: Pogorzeleca Peter J. , Reid David H. , Tocher Derek A. , Wilton-Ely James D. E. T.
Published: August 2018

The coordination chemistry of the unusual, pyrrole-stabilised thioaldehyde molecules, 3,5-dimethylpyrrole-2-carbothioaldehyde (HSPyMeHMe) and 3,5-dimethyl-4-ethylpyrrole-2-carbothioaldehyde (HSPyMeEtMe) has been investigated with nickel, palladium and platinum in the complexes [M(κ2- SPyMeRMe)2] (M = Ni, Pd, Pt; R = H, Et). The structure of the cyclometallated derivative [Pd(η2- C,N-C6H4CH2NMe2)(κ2-SPyMeEtMe)] was determined by X-ray diffraction.
N-Aryl Anions: Half Way between Amides and Carbanions
Authors: von Bülow Rixa , Deuerlein Stephan , Stey Thomas , Herbst-Irmer Regine , Gornitzka Heinz , Stalke Dietmar
Published: August 2018

A ‘carbanion’ can coordinate to a metal like an ‘amide’ if there is a nitrogen atom present to withdraw electron density from the formally negatively charged carbon center. On the other hand, shifting the negative charge from the amido nitrogen atom to the carbon substituent should convert an ‘amidic’ into a ‘carbanionic’ coordination behavior. This seems feasible with various substituents at the aromatic ring in a primary amide. This paper is concerned with the influence of aromatic substitution, as well as with the nature of the metal ion on the coordination mode of an amide ligand. Discussed are the parent lithium anilide [(thf)2LiNH(C6H5)]2 (1), the pentafluorinated lithium anilide [(thf)2LiNH(C6F5)]2 (2) and the lithium amino benzonitrile [(thf)2LiNH(C6H4
pCN)]2 (3). All amide ligands coordinate the lithium cation exclusively with their amido nitrogen atom. In the dimeric structure of 1 the atom can be regarded to be sp2-hybridized. Fluorine substitution of the ring results in a slightly more pronounced coupling of the negative charge to the aromatic ring. A para-nitrile group further enhances quinoidal perturbation of the C6-perimeter from six-fold symmetry. Consequently, the ipso- and ortho-carbon atoms of the ring are partially negative charged. Those carbon atoms are only attractive for the soft rubidium cation in an aza allylic coordination in [(thf)2RbNH(C6H4
pCN)]n (4) but not to the hard lithium cation.
Oxidative Addition of Methyl Iodide to Dinuclear Gold(I) Amidinate Complex: Schmidbaur’s Breakthrough Reaction Revisited with Amidinates
Authors: Abdou Hanan E. , Mohamed Ahmed A. , Fackler John P.
Published: August 2018

Oxidative-addition of methyl iodide, CH3I, to the dinuclear gold amidinate [Au2(o-Me2-form)2] in THF generates a metal-metal bonded Au(II) product, formulated as [Au2(o-Me2-form)2CH3I], in quantitative yield under nitrogen at 0 °C and in absence of light. The product is characterized by 1H NMR, elemental analysis and preliminary X-ray crystallography.
(EtZn)4Zn2(PSitBu3)4 – a Homometallic Phosphanediide of Zinc with a Novel Zn6P4 Cage
Authors: Westerhausen Matthias , Sapelza Gerhard , Zabel Manfred , Pfitzner Arno
Published: August 2018

The metalation of tri(tert-butyl)silylphosphane with diethylzinc yields quantitatively the title compound tetraethyltetrakis(tri(tert-butyl)silylphosphanediido)hexazinc (1) with a novel Zn6P4 cage with two Zn2P2 rings interconnected by two zinc atoms.
The Zinc Aqua Complex of a Tetrapodal Pentaamine Ligand and its Reactivity towards Carbon Dioxide
Authors: Pitarch López Jesús , Heinemann Frank W. , Grohmann Andreas
Published: August 2018

In the context of derivatisation studies of the pentaamine ligand 2,6-C5H3N[CMe(CH2NH2)2]2 (2-(6-(1,3-diamino-2-methylpropan-2-yl)pyridin-2-yl)-2-methylpropane-1,3-diamine, 1), we explored its zinc(II) coordination chemistry. With ZnBr2 in hot aqueous ethanol, in the absence of Lewis acid, the aqua complex [Zn(1)(H2O)]Br2 (2) is obtained, in which the pentaamine ligand acts as a square-pyramidal coordination cap. Single crystal structure data for the dihydrate of 2 are reported. In methanol solution, the complex is reactive towards carbon dioxide, and spectroscopic data (IR, 13C NMR) indicate the reversible formation of the dinuclear methyl carbonate complex [(Zn(1))2(μ2-(η1-O,η1-O)O2COCH3)]Br3.
Die Kristallstruktur von 1,3-Dicyclohexyl- 4,5-dimethylimidazolium- Dicyanomethylid / The Crystal Structure of 1,3-Dicyclohexyl-4,5- dimethylimidazolium Dicyanomethylide
Authors: Kuhn Norbert , Steimann Manfred , Sweidan Kamal
Published: August 2018

The crystal structure of 1,3-dicyclohexyl-4,5-dimethylimidazolium dicyanomethylide (6, [ImH][HC(CN)2]), obtained from the carbene Im and malodinitrile, reveals the presence of ion pairs connected by NHC hydrogen bonds.
Synthese und Kristallstruktur von Tetramesityldibismutan / Synthesis and Crystal Structure of Tetramesityldibismuthane
Authors: Balázs Lucia , Breunig Hans Joachim , Lork Enno
Published: August 2018

Tetramesityldibismuthane is obtained by the reaction of Mes2BiCl (Mes = 2,4,6-(CH3)3C6H2) and LiEH4 (E = B, Al) with intermediate formation of Mes2BiH. Crystals of Mes4Bi2 consist of centrosymmetric tetramesityldibismuthane molecules in the trans conformation. The value of the Bi-Bi bond length is 3.087(3) Å .
Hyperconjugation In Trialkylboranes Shown By Indirect Nuclear Spin-Spin Coupling Constants. Experimental Data And Density Functional Theory (Dft) Calculations
Authors: Wrackmeyer Bernd , Tok Oleg L.
Published: August 2018

Trimethylborane (1), triethylborane (2), 1,3-dimethyl-1-boracyclopentane (3), 1-methyl-1- boracyclohexane (4), 9-methyl- and 9-ethyl-9-borabicyclo[3.1.1]nonane [5(Me) and 5(Et)], and 1- boraadamantane (6) were studied by 11B and 13C NMR spectroscopy with respect to coupling constants 1J(13C,11B) and 1J(13C,13C). Results of DFT calculations at the B3LYP/6-311+g(d,p) level of theory show satisfactory agreement with the experimental data. Hyperconjugation arising from C-C σ bonds adjacent to the tricoordinate boron atom is indicated, in particular for 1-boraadamantane (6), by the optimised calculated structures, and by the experimental and calculated data 1J(13C,13C). The calculated magnitude of 1J(13C,1H) for carbon atoms adjacent to boron becomes significantly smaller if the optimised structures suggest hyperconjugative effects arising from these C-H bonds
Zr Stabilized Ti5Te4-Type Hafnium Telluride
Authors: He Meng , Simon Arndt , Duppel Viola
Published: August 2018

A new Ti5Te4-type compound, Zr stabilized hafnium telluride was discovered and characterized with electron crystallography. Microanalyses and preparative work show that Zr stabilizes Ti5Te4- type hafnium telluride and destabilizes the competing phase, Hf3Te2
The First Isolation Of A Phlegmacin Type Pigment From The Ascomycete Xylaria Euglossa
Authors: Wang Xing-Na , Tan Ren-Xiang , Wang Fei , Steglich Wolfgang , Liu Ji-Kai
Published: August 2018

A new pigment, phlegmacin A 8,8’-di-O-methyl ether (1), was isolated from fruiting bodies of Xylaria euglossa (Ascomycota) along with the known fungal pigments (S)-torosachrysone-8-O-methyl ether (2) and emodin-6,8-di-O-methyl ether (3). The structure of compound 1 was established on the basis of its spectroscopic data and the absolute configuration determined as P and 3’S by comparing the CD and 1H NMR spectra of 1 with those of the phlegmacins 4 and 5. Compound 1 represents the first phlegmacin type pigment isolated from the ascomycete
Some Chemical Constituents Of Terminalia Glaucescens And Their Enzymes Inhibition Activity
Authors: Rahman Atta-ur , Zareen Seema , Choudhary M. Iqbal , Akhtar M. Nadeem , Rahman Atta-ur , Ngounou F. N.
Published: August 2018

A new triterpenoid, glaucinoic acid (2α, 3β, 19α, 24-tetrahydroxyolean-12-en-30-oic acid) (1) along with several known compounds, arjunic acid (2), arjungenin (3), sericoside (4), and friedelin (5) were isolated from the stem barks of Terminalia glaucescens. These compounds showed β - glucuronidase inhibitory activity. The structures were identified on the basis of spectroscopic techniques
Catalytic Formation and Crystal Structure of Cyanoguanylurea H2NC(=O)NHC(NH2)NCN
Authors: Lotsch Bettina V. , Schnick Wolfgang
Published: August 2018

The ion exchange reaction between ammonium cyanoureate NH4[H2NC(=O)NCN] and zinc chloride yielded single crystals of the urea derivative cyanoguanylurea H2NC(=O)NHC(NH2)NCN, which was obtained as a by-product alongside zinc cyanoureate and traces of ammonium chloride. It is assumed that owing to its Lewis and Brønsted acidity, the hydrated Zn2+ ion acts as a catalyst, promoting the degradation of the cyanoureate anion with subsequent formation of the title compound. The crystal structure was solved in the centrosymmetric space group P21/n (a = 476.7(1), b = 965.3(2), c = 1165.6(2) pm, β = 97.75(3)°, V = 531.4(2) 106 pm3, Z = 4, T = 200 K). In the solid there are non-planar cyanoguanylurea molecules with a dicyandiamide-type C-N system, building up a layered structure with sparse interlayer contacts and significant hydrogen bonding within the layers
Di-, Hexa- und Deca-substituierte Decaphenylferrocene / Di-, Hexa- and Deca-Substituted Decaphenylferrocenes
Authors: Schumann Herbert , Sühring Klaudia
Published: August 2018

5-Bromo-1,2,3,4-tetraphenyl-5-p-tolyl-1,3-cyclopentadiene (1a), 5-Bromo-1,4-di-phenyl-2,3,5- tri-p-tolyl-1,3-cyclopentadiene (1b), 5-Bromo-1,2,3,4,5-penta-p-tolyl-1,3-cyclopentadiene (1c), 5- Bromo-1,2,3,4-tetraphenyl-5-p-bromophenyl-1,3-cyclopentadiene (1d), and 5-Bromo-1,2,3,4-tetraphenyl- 5-p-anisyl-1,3-cyclopentadiene (1e) react with ironpentacarbonyl in m-xylene to yield the corresponding ferrocenes 2a - 2e. In the course of the purification procedure, reactions with HCl and the solvent m-xylene are observed which yield the mixed ionic sandwich complexes [(C5Ph4C6H4Me)Fe(C6H4Me2)]+Cl− (3a), [(C5Ph2(C6H4Me)3)Fe(C6H4Me2)]+Cl− (3b), [(C5(C6H4Me)5)Fe(C6H4Me2)]+Cl− (3c), [(C5Ph4C6H4Br)Fe(C6H4Me2)]+Cl− (3d), and [(C5Ph4 C6H4OMe)Fe(C6H4Me2)]+Cl− (3e), respectively, along with the corresponding cyclopentadienes 1,2,3,4-tetraphenyl-5-p-tolyl-1,3-cyclopentadiene (4a), 1,4-diphenyl-2,3,5-tri-p-tolyl-1,3- cyclopentadiene (4b), 1,2,3,4,5-penta-p-tolyl-1,3-cyclopentadiene (4c), 1,2,3,4-tetraphenyl-5-pbromphenyl- 1,3-cyclopentadiene (4d), and 1,2,3,4-tetraphenyl-5-p-anisyl-1,3-cyclopentadiene (4e). The compounds have been characterized by elemental analysis, IR, NMR, and mass spectra, and, in the case of 2c, by 13C-CPMAS spectroscopy and X-ray powder diffractometry
ATheoretical Study on the Existence and Structures of Some Hypothetical First-Row Transition-Metal M(NCN) Compounds
Authors: Launay Maxence , Dronskowski Richard
Published: August 2018

The family of quasi-binary cyanamides/carbodiimides of general formula M(NCN) containing divalent 3d transition metals (M = Mn, Fe, Co, Ni and Cu) has been studied by density-functional means; until now, such light transition-metal compounds have not yet been prepared. Twenty-eight structural models have been considered based on known compounds having NCN2− and other triatomic anionic entities (e. g., thiocyanates). After performing LDA geometry optimizations, the relative energetic orderings are interpreted in terms of geometrical factors such as molar volumes and effective coordination numbers; dense structures with octahedral metal coordinations and highspin electronic configurations are to be expected, especially for the earlier metals (Mn and Fe). Based on GGA total-energy calculations, there is a chance to synthesize these enthalpically unstable compounds, not from the elements but via appropriate exchange reactions employing fairly stable cyanamide/carbodiimide precursors and yielding stable or volatile metal halides which can be removed from the chemical equilibria
Protoilludane Sequiterpenoids, Echinocidins C and D Produced by a Decay Causing Fungal Strain Echinodontium tsugicola
Authors: Shiono Yoshihito , Suzuki Shinsuke , Murayama Tetsuya , Ikeda Michimasa , Abe Yoshiaki
Published: August 2018

New protoilludane sequiterpenoids, echinocidins C (3) and D (4) have been isolated from liquid culture of Echinodontium tsugicola. Their structures have been established on the basis of spectral analysis. The biological activities of 3 and 4 were examined by bioassay with lettuce seedlings
Gemischte Thio/Oxo-Orthovanadate Na3[VSxO4 –x] (x = 2, 3): Darstellung – Strukturen – Eigenschaften / Mixed Thio/Oxo Orthovanadates Na3[VSxO4−x] (x = 2, 3): Synthesis – Crystal Structures – Properties
Authors: Schnabel Simone , Röhr Caroline
Published: August 2018

Mixed sodium thio/oxo orthovanadates(V), dark red Na3[VS3O] and orange red Na3[VS2O2], were synthesized via reactions in the melt starting from V, Na, Na2S, Na2O and sulfur. The structure of the low temperature phase of Na3[VS3O] (space group Pnma, a = 589.5(3), b = 962.8(5), c = 1186.6(6) pm, Z = 4, R1 = 0.0494) contains anions [VS3O]3− almost identical to those known from the high temperature form, β -Na3[VS3O] (space group Cmc21, a = 968.4(4), b = 1194.6(4), c = 590.5(2) pm, Z = 4, R1 = 0.0291). The second order phase transition between these two forms at 536 °C was studied by temperature dependent powder diffraction and explained on the basis of a comparison of the anion packing in the two related structures. The packing of the dithiodioxovanadate anions in Na3[VS2O2] (space group Pbca, a = 1162.7(2), b = 592.71(12), c =1766.7(4) pm, Z = 8, R1 = 0.0312) is also closely related. The chemical bonding in the anions [VS3O]3− and [VS2O2]3− of approximately ideal C3v and C2v symmetry is discussed on the basis of FP-LAPW band structure calculations and force constants obtained from Raman spectroscopy. The decrease of the calculated band gaps with increasing S content x in Na3[VSxO4−x] is in accordance with the optical properties showing a gradually deepening of the crystal and solution colour. Discernible trends in the chemical bonding in this series of mixed thio-oxo anions also include the amount of π bonding of the V-O and V-S bonds and the corresponding variation of force constants and V-O/V-S distances.
La3Cl3BC – Structure, Bonding and Electrical Conductivity
Authors: Zeng Hui-Yi , Okudera Hiroki , Zheng Chong , Mattausch Hansjürgen , Kremer Reinhard K. , Simon Arndt
Published: August 2018

A new rare earth carbide boride halide, La3Cl3BC, has been prepared by heating a mixture of stoichiometric quantities of LaCl3, La, B and C at 1050 °C for 10 days. La3Cl3BC (La3Br3BC type) crystallizes in the monoclinic system with space group P21/m (No. 11), a = 8.2040(16), b = 3.8824(8), c=11.328(2)Å , β =100.82(3)°. In the structure, monocapped trigonal prisms containing B-C units are condensed into chains along the b direction, and the chains are further linked by Cl atoms in the a and c directions. The condensation results in a polymeric anion 1
∞[BC] with a spine of B atoms in a trigonal prismatic coordination by La, and the C atoms attached in a square pyramidal coordination. The B-B and B-C distances are 2.16 and 1.63 Å , respectively. La3Cl3BC is metallic. The EH calculation shows that the distribution of valence electrons can be formulated as (La3+)3(Cl−)3(BC)5− · e−.
Syntheses, Crystal Structures and Thermal Stability of Co(II) and Zn(II) Complexes with Ethyl Carbazate
Authors: Zhang Tong-Lai , Song Jiang-Chuang , Zhang Jian-Guo , Ma Gui-Xia , Yu Kai-Bei
Published: August 2018

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.
Preparation and Crystal Structures of M[(UO2)(SeO4)2(H2O)](H2O)4 (M = Mg, Zn)
Authors: Krivovichev Sergey V. , Kahlenberg Volker
Published: August 2018

The crystals of two isostructural uranyl selenates, M[(UO2)(SeO4)2(H2O)](H2O)4 (M = Mg, Zn), have been prepared by water evaporation from aqueous solutions. The structures have been solved by direct methods (M = Mg: P21/c, a = 8.4666(8), b = 11.6306(14), c = 13.1669(12) Å , β = 90.959(7)°, V = 1296.4(2) Å3, R1 = 0.061; M = Zn: P21/c, a = 8.4492(18), b = 11.5860(17), c = 13.240(3) Å , β = 92.382(18)°, V = 1294.9(4) Å3, R1 = 0.074). The structures are based upon [(UO2)(SeO4)2(H2O)]2− chains running parallel to the b axis and consisting of corner-sharing [UO6(H2O)]6− pentagonal bipyramids and [SeO4]2− tetrahedra. The equatorial planes of the uranyl pentagonal bipyramids are oriented approximately parallel to (001). The uranyl selenate chains are linked into sheets parallel to (010) by [M(H2O)6]2+ octahedra which share common H2O molecules with the [UO6(H2O)]6− pentagonal bipyramids.
Stereoselective Syntheses of Alkyl Z-2-(2-amino-4-oxo-1,3-selenazol- 5(4H)-ylidene)acetates in Solvent-Free Conditions, X-Ray Single Crystal Structure Analysis of Ethyl Z-2-(2-amino-4-oxo-1,3-selenazol- 5(4H)-ylidene)acetate
Authors: Ramazani Ali , Morsali Ali , Ganjeie Bijan , Kazemizadeh Ali Reza , Ahmadi Ebrahim , Kempe Rhett , Hertle Ivonne
Published: August 2018

Selenourea reacts with dialkyl acetylenedicarboxylates under solvent-free conditions to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl Z-2-(2-amino-4-oxo-1,3-selenazol- 5(4H)-ylidene)acetates, in good yields. The stereochemistry of the ethyl Z-2-(2-amino-4-oxo-1,3- selenazol-5(4H)-ylidene)acetate was established by X-ray single crystal structure analysis. The reaction is completely stereoselective.
A Proton-Catalyzed Dimerization of a 2-Amino-1,3-diene which Ultimately Yields a 3-Aminobicyclo[4.2.0]octa-2,4-diene
Authors: Maas Gerhard , Rahm Rainer
Published: August 2018

The 2-pyrrolidino-1,3-dienes (E)-5 and (Z)-5 are obtained by the reaction of lithium di(tertbutyl) cuprate with propyne iminium salt 3. Quantitative Z→E isomerization of 5 takes place within 4 hours at 20 °C. In benzene solution, (E)-5 slowly equilibrates with a [1,5]-H shift to form the 1-amino-1,3-diene derivative 6. In concentrated chloroform solution, however, (E)-5 is transformed into the 3-pyrrolidino-bicyclo[4.2.0]octa-2,4-diene 7 which is identified by X-ray crystal structure analysis. A mechanism for this transformation is proposed.
Der PrPS4-Strukturtyp und eine ”aufgefüllte“ Variante: Die Verbindungen TbPS4 und LiEuPS4 / The PrPS4 Type Structure and a Filled Variant: The Compounds TbPS4 and LiEuPS4
Authors: Jörgens Stefan , Alili Lirija , Mewis Albrecht
Published: August 2018

Colourless single crystals of TbPS4 (a = 10.696(2), c = 19.053(4) Å ) were obtained by reaction of the elements (750 °C; 30 h). The compound crystallizes with the PrPS4 type structure (I41/acd; Z = 16). The structure consists of isolated PS4 tetrahedra each surrounded by four Tb3+ cations. Both crystallographically different Tb3+ cations are coordinated by eight sulfur atoms which are part of four PS4 tetrahedra. Orange single crystals of LiEuPS4 (a = 11.498(2), c = 19.882(4) Å ) were prepared by reaction of Eu and P with Li2S4 (700 Å; 20 h). The crystal structure corresponds to the PrPS4 type, in which tubes running along [001] are occupied by Li atoms, which are surrounded by four S atoms in strongly distorted tetrahedra. LiS4 and PS4 tetrahedra are connected via common edges into alternating chains.
Synthesis of Some 2-Aminonitroethanes via Tin(II)chloride Mediated Addition Reaction of Bromonitromethane to Imines
Authors: Qaraqe Hazem , Mahasneh Ali S.
Published: August 2018

In the presence of tin(II)chloride, bromonitromethane reacts with imines derived from aromatic aldehydes and ammonia to yield 2-amino-2-aromatic substituted nitroethane derivatives via an addition reaction in good yields.
7-O-Methylcyanidin 3-O-β-D-Galactopyranoside, a Novel Anthocyanin from Mango (Mangifera indica L. cv. ‘Tommy Atkins’) Peels
Authors: Berardini Nicolai , Schieber Andreas , Klaiber Iris , Beifuss Uwe , Carle Reinhold , Conrad Jürgen
Published: August 2018

Mango (Mangifera indica L.) is one of the most important tropical fruits and its pulp is known to be a rich source of carotenoids. Investigations on the phenolic composition of the peels of a red-colored cultivar (cv. ‘Tommy Atkins’) revealed the presence of a new anthocyanin, 7-O-methylcyanidin 3-O- β -D-galactopyranoside. Its structure was elucidated by extensive 1D and 2D NMR studies, MS, and chemical transformation.
The High-Pressure Modification of CePtSn – Synthesis, Structure, and Magnetic Properties
Authors: Riecken Jan F. , Heymann Gunter , Soltner Theresa , Hoffmann Rolf-Dieter , Huppertz Hubert , Johrendt Dirk , Pöttgen Rainer
Published: August 2018

The high-pressure (HP) modification of CePtSn was prepared under multianvil high-pressure (9.2 GPa) high-temperature (1325 K) conditions from the normal-pressure (NP) modification. Both modifications were investigated by powder and single crystal X-ray data: TiNiSi type, Pnma, a = 746.89(9), b = 462.88(4), c = 801.93(7) pm, wR2 = 0.0487, 452 F2 values, 20 variable parameters for NP-CePtSn, and ZrNiAl type, P6̅2m, a = 756.919(5), c = 415.166(4) pm, wR2 = 0.0546, 252 F2 values, 14 variable parameters for HP-CePtSn. Both modifications are built up from platinumcentered trigonal prisms. Together, the platinum and tin atoms form different three-dimensional [PtSn] networks in which the cerium atoms fill channels. The crystal chemistry and chemical bonding of NP- and HP-CePtSn is discussed. Susceptibility measurements of HP-CePtSn indicate Curie-Weiss behavior above 40 K with an experimental magnetic moment of 2.55(1) μB/Ce atom, indicating trivalent cerium. No magnetic ordering could be detected down to 2 K.
Efficient and Practical Procedures for the Synthesis of Bis-benzimidazoles in Dry Media under Various Reaction Conditions
Authors: Aghapoor Kioumars , Mohsenzadeh Farshid , Darabi Hossein Reza
Published: August 2018

Some different approaches have been developed in order to determine the most efficient preparation of bis-benzimidazoles 1a - f under solvent-free conditions. All of the selected methods are simple, avoiding heating with corrosive mineral acids. Heating of the reactants on a sand bath method appears to have higher efficiency.
Dibromotyrosine Derivatives, a Maleimide, Aplysamine-2 and Other Constituents of the Marine Sponge Pseudoceratina purpurea
Authors: Kijjoa Anake , Bessa Júlia , Wattanadilok Rawiwan , Sawangwong Pichan , Nascimento Maria São José , Pedro Madalena , Silva Artur M. S. , Eaton Graham , Soest Rob van , Herz Werner
Published: August 2018

A collection of the marine sponge Pseudoceratina purpurea from the Gulf of Thailand furnished aplysamine-2, two new bromotyrosine derivatives purpuroceratic acids A and B, two known bromotyrosine derivatives, 3-maleimide-5-oxime and common sponge constituents. Aplysamine-2, purpuroceratic acid A and 3-maleimide oxime were evaluated for their in vitro anticancer activity against three cancer cell lines, but only aplysamine-2 exhibited moderate dose dependent growth inhibitory effects.
Stereoselectivity during a Dieckmann Analogous Cyclization of (Piperazin-2-yl)propionic Acid Esters
Authors: Geiger Christian , Zelenka Christel , Fröhlich Roland , Wibbeling Birgit , Wünsch Bernhard
Published: August 2018

The primary Dieckmann cyclization product of the methyl (3,6-dioxopiperazin-2-yl)propionate was trapped with chlorotrimethylsilane and recrystallized. The X-ray crystal structure analysis showed (S)-configuration of the novel chiral centre. This configuration supports the hypothesis that formation of the stable lithium chelate is responsible for shifting this unusual Dieckmann cyclization towards the bicyclic product.
Synthesis, Crystal Structure and Antitumor Study of a Cobalt(II) Complex of the 2-Acetylpyrazine Thiosemicarbazone
Authors: Li Ming Xue , Zhou Jing , Wang Zi Liang , Wang Jing Ping
Published: August 2018

The title complex [Co(C7H8N5S)2]·2H2O has been synthesized and characterized by IR and UV spectral studies. The structure of the compound has been determined by single-crystal X-ray diffraction. The complex consists of discrete monomeric molecules with octahedrally hexacoordinate cobalt(II) ions, where two acetylpyrazine thiosemicarbazones act as NNS tridentate ligands coordinated to the central cobalt atom via the pyrazine nitrogen, azomethine nitrogen and sulfur atoms. Hydrogen bonds link the different components to stabilize the crystal structure. The antitumor activity of the title complex was tested against A549 lung cancer cell line. The complex exhibited lower antitumor activity, as compared to the free ligand.
Two Novel One-dimensional Inorganic-Organic Hybrids Constructed from [H2W12O40]6– Clusters and Lanthanide-organic Complexes: [(C5H5N-CO2)2Ln(H2O)3]2[H2W12O40]·nH2O (C5H5N-CO2 = Pyridine-4-carboxylate; Ln = La3+, n = 5; Ce3+, n = 7)
Authors: Pang Hai-jun , Chen Ya-guang , Meng Fan-xia , Shi Dong-mei
Published: August 2018

Two novel polyoxotungstate-based rare earth compounds, [(C5H5N-CO2)2Ln(H2O)3]2- [H2W12O40] · nH2O (C5H5N-CO2 = pyridine-4-carboxylate; Ln = La3+ (1), n = 5; Ce3+ (2), n = 7), have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. The isostructural compounds 1 and 2 exhibit onedimensional (1D) zig-zag chains, in which the dinuclear lanthanide complexes act as bridging linkers and the [H2W12O40]6− groups serve as bidentate ligands. The results of cyclic voltammetry (CV) show that compounds 1 and 2 undergo two two-electron redox processes, similar to that of the parent (NH4)6[H2W12O40] ·3H2O, and also reveal that the pH of the supporting electrolytic solution has a notable effect on the electrochemical behavior of compound 2.
2′-Oxoethyl Flavin Revisited
Authors: Svoboda Jiří , König Burkhard , Sadeghian Keyarash , Schützb Martin
Published: August 2018

The present work investigates the possibility of using 2'-oxoethyl flavin (2) as a starting material for the construction of more complicated flavin-based molecules. 2'-Oxoethyl flavin (2), prepared by oxidative degradation of commercially available riboflavin 1, is however a rather untypical aldehyde. It prefers the hydrated gem-diol form 4 in aqueous solution. Ab initio electronic structure calculations, carried out at the level of Møller-Plesset perturbation theory of second order (MP2), predict the existence of an intramolecular hydrogen bond between one of the hydroxy groups of the diol and the N1 atom of the flavin skeleton. This result is supported by 1H NMR measurements which indicate an interaction between the hydroxy groups and the conjugated ring system. We postulate that this rather strong intramolecular hydrogen bond is the origin of the enhanced stability of the gem-diol over the aldehyde form 2.

Synthetic applicability of 2'-oxoethyl flavin 2 is limited by low solubility in most organic solvents and sensitivity to basic conditions. The aldehyde functional group is surprisingly reluctant to nucleophilic attack, and several reactions quite typical for aldehydes failed. Nevertheless, reductive amination led to the expected secondary amine 7. Solubility of the molecule thus increased, and a new amino group was introduced.
A New Spiroaxane Sesquiterpene from Cultures of the Basidiomycete Pholiota adiposa
Authors: Liu Dong-Ze , Jia Rui-Rui , Wang Fei , Liu Ji-Kai
Published: August 2018

A new spiroaxane sesquiterpene (15-hydroxy-6α,12-epoxy-7β ,10αH,11β H-spiroax-4-ene, 1) was isolated from the culture broth of the basidiomycete Pholiota adiposa. The structure of 1 was established on the basis of MS, IR, ID, and 2D NMR experiments.
A Novel Sesquiterpene from the Basidiomycete Boletus calopus
Authors: Liu Dong-Ze , Wang Fei , Jia Rui-Rui , Liu Ji-Kai
Published: August 2018

A novel sesquiterpene named cyclopinol (1) together with two related known compounds, cyclocalopin A (2) and Oacetylcyclocalopin A (3), has been isolated from the basidiomycete Boletus calopus. The structure of compound 1 was established on the basis of spectral methods (MS, IR, 1D, and 2D NMR experiments).
Metal Complexes of Biologically Important Ligands, CLXIX [1]. Palladium(II) and Platinum(II) N,O-Chelate Complexes (R3P)(Cl)M(α-aminoacidate) with the Anions of Serine, Threonine, 3,4-Dehydroproline and 4-Hydroxyproline
Authors: Schuhmann Elfriede , Beck Wolfgang
Published: August 2018

The N,O-chelates M(3,4-dehydro-D,L-prolinate)2 (M = Ni, Cu) have been obtained from Ni(OH)2 or Cu(OH)2 and the amino acid. The complexes (R3P)(Cl)M(α-aminoacidate) (M= Pd, Pt) have been synthesized from the chloro bridged compounds (R3P)(Cl)M(μ-Cl)2M(PR3)Cl (M = Pd, Pt; R = Et, n-Bu, Ph) and the potassium salts of the α-amino acids D,L-serine, D,L-threonine, 3,4-dehydro-D,Lproline and 4-hydroxy-L-proline. According to the 31P NMR and 13C NMR spectra the complexes with serinate and threoninate are formed as mixtures of cis/trans N-M-P isomers, whereas for the palladium complexes with 3,4-dehydroprolinate and 4-hydroxyprolinate a single isomer is observed
Catalytic Performance of Heteropoly Acids on Different Supports in the Synthesis of Dihydropyrimidones
Authors: Rafiee Ezzat , Eavani Sara , Babaee Elaheh , Toodehroosta Fatemeh , Daneshpazhuh Kataun
Published: August 2018

Keggin heteropoly acids supported on solids with different nature were used in the Biginelli reaction in order to obtain dihydropyrimidones. The results show that the activity of the catalysts is dependent on the supports used to obtain the catalysts. This method consistently has the advantages of excellent yield, mild reaction conditions, ease of workup, survival of different functional groups, and short reaction times
A Keggin-type Arsenotungstate Anion-supported Transition Metal Complex: Hydrothermal Synthesis and Characterization of [Fe(2,2′-bipy)3]1.5[AsWVI
10WV
2O40Fe(2,2′-bipy)2(H2O)] · 0.25H2O
Authors: Li Ming-Xue , Niu Hong-Yu , Wang Wei , Wang Jing-Ping
Published: August 2018

A Keggin-type arsenotungstate anion-supported iron-bipyridine complex, [Fe(2,2'-bipy)3]1.5- [AsWVI
10WV
2O40Fe(2,2'-bipy)2(H2O)] · 0.25H2O, has been hydrothermally synthesized and characterized by IR and ESR spectra, TG-DTA analysis, and single crystal X-ray diffraction. Each structural unit of the title compound consists of one [AsWVI
10WV
2O40Fe(2,2'-bipy)2(H2O)]3− heteropolyanion, one and a half [Fe(2,2'-bipy)3]2+ cations, and a quarter of an H2O molecule. In the heteropolyanion the [Fe(2,2'-bipy)2(H2O)]2+ unit is covalently bonded to the reduced Keggin polyoxoanion [AsWVI
10WV
2O40]5−. The complex ismonoclinic, space group C2/c with a = 46.8079(13), b = 14.3990(4), c = 26.1085(8) Å , β = 90.00(5)°, Z = 8, Dc = 3.10 g/cm3
The High-temperature Modification of LuAgSn and High-pressure High-temperature Experiments on DyAgSn, HoAgSn, and YbAgSn
Authors: Heying Birgit , Rodewald Ute Ch. , Heymann Gunter , Hermes Wilfried , Schappacher Falko M. , Riecken Jan F. , Sebastian Peter , Huppertz Hubert , Pöttgen Rainer
Published: August 2018

The high-temperature modification of LuAgSn was obtained by arc-melting an equiatomic mixture of the elements followed by quenching the melt on a water-cooled copper crucible. HT-LuAgSn crystallizes with the NdPtSb-type structure, space group P63mc: a = 463.5(1), c = 723.2(1) pm, wR2 = 0.0270, 151 F2, and 11 variables. The silver and tin atoms build up two-dimensional, puckered [Ag3Sn3] networks (276 pm Ag-Sn) that are charge-balanced and separated by the lutetium atoms. The Ag-Sn distances between the [Ag3Sn3] layers of 294 pm are much longer. Single crystals of isotypic DyAgSn (a = 468.3(1), c = 734.4(1) pm, wR2 = 0.0343, 411 F2, and 11 variables) and HoAgSn (a = 467.2(1), c = 731.7(2) pm, wR2 = 0.0318, 330 F2, and 11 variables) were obtained from arc-melted samples. Under high-pressure (up to 12.2 GPa) and high-temperature (up to 1470 K) conditions, no transitions to a ZrNiAl-related phase have been observed for DyAgSn, HoAgSn, and YbAgSn. HT-TmAgSn shows Curie-Weiss paramagnetism with μeff = 7.53(1) μB/Tm atom and θP = −15.0(5) K. No magnetic ordering was evident down to 3 K. HT-LuAgSn is a Pauli paramagnet. Room-temperature 119Sn Mössbauer spectra of HT-TmAgSn and HT-LuAgSn show singlet resonances with isomer shifts of 1.78(1) and 1.72(1) mm/s, respectively
NMR Determination of the Structure of Azolopyrimidines Produced from Reaction of Bidentate Electrophiles and Aminoazoles
Authors: Hassaneen Huwaida M. E. , Hassaneen Hamdi M. , Khiry Sherif F.M. , Pagni Richard M.
Published: August 2018

A variety of aminoazoles were reacted with bidentate electrophiles producing azolopyrimidines. The regioselectivity of the nucleophilic attack could be defined from the 13C chemical shift of the pyrimidine carbons and through NOE experiments
Die Lanthanoid(III)-Chlorid-Oxoselenate(IV) MCl[SeO3] (M = Sm–Lu) imHoCl[TeO3]- oder B-Typ / The Lanthanoid(III) Chloride Oxoselenates(IV) MCl[SeO3] (M = Sm–Lu) with HoCl[TeO3]- or B-Type Structure
Authors: Lipp Christian , Schleid Thomas
Published: August 2018

The B-type lanthanoid(III) chloride oxoselenates(IV) MCl[SeO3] (M = Sm- Lu) crystallize in the orthorhombic space group Pnma (no. 62) with Z = 4 in the structure type of HoCl[TeO3]. Their lattice constants are decreasing following the lanthanoid contraction from a = 730.01(7), b = 707.90(7), c = 895.64(9) pm for SmCl[SeO3] to a = 714.63(7), b = 681.76(7), c = 864.05(9) pm for LuCl[SeO3]. In contrast to NdCl[SeO3], the only representative of the A-type structure, where the coordination numbers of the Nd3+ cations are 7+2 and 8, the B-type structure is dominated by pentagonal bipyramids [MO5Cl2]9− (CN(M3+) = 7), which are connected via trans-oriented O・ ・ ・O edges to 1
∞{[MOe
4/2Ot
1/1Clt
2/1]5−} chains (e = edge-sharing, t = terminal) running parallel to the [010] direction. Their inclination relative to each other allows for an alternating interconnection of these chains via Cl− and ψ1-tetrahedral [SeO3]2− anions to form a three-dimensional structure. The distances within the [SeO3]2− groups are in the normal range (d(Se−O) = 165 - 172 pm), while those of the O2− and Cl− anions to the central M3+ cation diminish in dependence of the increasing atomic number (d(M−O) = 226 - 244 pm / 216 - 232 pm, d(M−Cl) = 277 - 278 pm / 266 - 270 pm, M = Sm/Lu). For the synthesis of the chloride oxoselenates(IV) MCl[SeO3] the respective lanthanoid sesquioxide (M2O3) and selenium dioxide (SeO2) were reacted with either an eutectic mixture of RbCl and LiCl or with the corresponding lanthanoid trichloride (MCl3) in evacuated silica ampoules for either five weeks at 500 °C or one week at 850 °C.
Local Environment and Electronic Structure in K2NiF4-type La2Li0.50Cu0.50O4 Doped by 57Fe
Authors: Presniakov Igor , Demazeau Gerard , Baranov Alexei , Sobolev Alexei , Gubaidulina Tatiyana , Rusakov Viyacheslav
Published: August 2018

The 57Fe Mössbauer spectrum of the oxide La2Li0.50Cu0.50O4 doped with 57Fe (1 at.-%) underlines at 300 K the presence of three different components: two corresponding to the substitution of 57Fe probe atoms for respectively “Cu3+” [Fe(1)] and Li+ [Fe(3)] and the third [Fe(2)] attributed to 57Fe associated with oxygen vacancies. A decrease of the temperature down to 77 K does not lead to essential changes of the Mössbauer parameters corresponding to the Fe(1) and Fe(2) sub-spectra. On the contrary, a drastic change occurs in the Fe(3) sub-spectrum which has been interpreted by a displacement of the charge-transfer equilibrium Fe4+(3) + O2− → Fe3+(3) + O(L̲) at the Li+ sites.
Formal Total Synthesis of (±)-Trichodiene via Claisen Rearrangement and Robinson Annulation
Authors: Jung Jae-Chul , Jung Young-Jo , Park Oee-Sook
Published: August 2018

A facile formal total synthesis of (±)-trichodiene was achieved by employing Claisen rearrangement and Robinson annulation as synthetic key strategies.
1,3-Dipolar Cycloadditions of (1Z,4R*,5R*)-4-Benzamido-3-oxo- 5-phenylpyrazolidin-1-ium-2-ides to Ethyl Propiolate
Authors: Pezdirc Lidija , Stanovnik Branko , Svete Jurij
Published: August 2018

1,3-Dipolar cycloadditions of (1Z,4R*,5R*)-4-benzamido-3-oxo-5-phenylpyrazolidin-1-ium-2- ides 3a - e to ethyl propiolate (4) were studied. The reactions were carried out in anisole under reflux and in anisole under microwave irradiation at 150°C. All reactions were quite non-selective and furnished mixtures of isomeric cycloadducts, 5, 5′ , 6, and 6′ , with ethyl (1S*,6R*,7R*)-6-benzamido-1- (4-nitrophenyl)-5-oxo-7-phenyl-1,5,6,7-tetrahydropyrazolo[1,2-a]pyrazole-2-carboxylates 5a - e as the major isomers. Pure major isomers 5a - e were obtained in low to moderate yields upon thorough chromatographic workup (CC followed by MPLC). The structures of cycloadducts 5, 5′ , 6, and 6′ were determined by 1H NMR and NOESY spectroscopy.
Diverse Reactivities of Acetylenic Iminium Salts Toward 1,3-Oxazolium-5-olates (Münchnones)
Authors: Gerster Holger , Maas Gerhard
Published: August 2018

The acetylenic iminium salts [(c-C3H5)C≡C-C(Ar)=N+Me2]OTf, Ar = phenyl (1a) or 2- thienyl (1b), both react in different ways with three mesoionic münchnones, namely 3-methyl-1,3-oxazolium-5-olate (2), 3-methyl-2-phenyl-1,3-oxazolium-5-olate (6) and 3-methyl-2-phenyl-4- trifluoroacetyl-1,3-oxazolium-5-olate (9). With 2, a [3+2] cycloaddition reaction followed by extrusion of CO2 yields pyrroles 5a, b. In the case of 6, the new münchnones 7a, b are obtained which result from an electrophilic substitution at C-4 by the acetylenic iminium cation. In contrast to 1a, b, the 4,4-but-2-yne 1-iminium salt 1c reacts with münchnone 6 to form pyrrole 8. Finally, the reaction of 1a, b and 9 affords (6-oxo-6H-pyran-3-yl)methylene iminium salts 10a, b under microwave heating conditions. The structures of pyrrole 5a, münchnone 7a, and trifluoromethyl-substituted pyranone 10a were established by single-crystal X-ray diffraction analysis.
Synthesis and Crystal Structures of 1-Alkoxy-3-alkylimidazolium Salts Including Ionic Liquids, 1-Alkylimidazole 3-oxides and 1-Alkylimidazole Perhydrates
Authors: Laus Gerhard , Schwärzler Alexander , Bentivoglio Gino , Hummel Michael , Kahlenberg Volker , Wurst Klaus , Kristeva Elka , Schütz Johannes , Kopacka Holger , Kreutz Christoph , Bonn Günther , Andriyko Yuriy , Nauer Gerhard , Schottenberger Herwig
Published: August 2018

Functionalized quaternary imidazolium salts were prepared with the intention to obtain new ionic liquids (ILs). Thus, more than forty 3-alkoxy-1-alkylimidazolium salts, 3-alkoxy-1-alkyl-2-methylimidazolium salts, 1-methylimidazole 3-oxide and 1,2-dimethylimidazole 3-oxide as well as their salts, 1,3-dihydroxyimidazolium salts and 1,3-dihydroxy-2-methylimidazolium salts were synthesized and characterized by spectroscopy and, to a limited extent, by viscosity and conductivity measurements. Results of fourteen single crystal X-ray structure determinations are reported, among them also the parent compounds 1-hydroxyimidazole 3-oxide and 1-hydroxy-2-methylimidazole 3- oxide. Selective debenzylation of 1-benzyloxy-3-methyl imidazolium salts and mono-demethoxylation of 1,3-dimethoxyimidazolium salts were achieved by hydrogenolysis. In addition, a crystalline semiperhydrate of 1,2-dimethylimidazole was characterized. Furthermore, an addition compound of 1-methylimidazole 3-oxide with tris(2-thienyl)borane and a silver carbene complex derived from 1-benzyloxy-3-methylimidazolium hexafluorophosphate was crystallized and characterized.
Calcium Carbodiimide Compounds Revisited – Syntheses, Single Crystal Structure Determination and Vibrational Spectra of Ca11N6[CN2]2, Ca4N2[CN2] and Ca[CN2]
Authors: Reckeweg Olaf , DiSalvo Francis J.
Published: August 2018

Single crystals of Ca11N6[CN2]2 (dark red needles, tetragonal, P42/mnm (no. 136), a = 1456.22(5), and c = 361.86(2) pm, Z = 2), Ca4N2[CN2] (transparent yellow needles, orthorhombic, Pnma (no. 62), a = 1146.51(11), b = 358.33(4), and c = 1385.77(13) pm, Z = 4) and Ca[CN2] (transparent, colorless, triangular plates, rhombohedral, R3̅m (no. 166), a = 369.00(3), and c = 1477.5(3) pm, Z = 3) were obtained by the reaction of Na2[CN2], CaCl2 and Ca3N2 (if demanded by stoichiometry) in arc-welded Ta ampoules at temperatures between 1200 - 1400 K. Their crystal structures were re-determined by means of single crystal X-ray structure analyses. Additionally, the Raman spectra were recorded on these same single crystals, whereas the IR spectra were obtained with the KBr pellet technique. The title compounds exhibit characteristic features for carbodiimide units with D∞h symmetry (d(C-N) = 121.7 - 123.8 pm and ∡ (N-C-N) = 180°). The vibrational frequencies of these units are in the expected range (Ca11N6[CN2]2: νs = 1230, νs = 2008; δ = 673/645/624 cm−1; Ca4N2[CN2]: νs = 1230, νs = 1986; δ = 672/647 cm−1; Ca[CN2]: νs = 1274, νs = 2031, δ = 668 cm−1). The structural results are more precise than the previously reported data, and with the newly attained Raman spectrum of Ca11N6[CN2]2 we correct data reported earlier.
Mannich Bases as Synthetic Intermediates: Alkylation of Amines and Diamines with Bis-ketonic Mannich Bases
Authors: Afsah Elsayed M. , Hammouda Metwally , Khalifa Mona M. , Al-shahaby Essam H.
Published: August 2018

The bis-ketonic Mannich base, N,N-bis(β -benzoylethyl)methylamine hydrochloride (1) reacts with primary arylamines and diamines to give ketonic sec-arylamines 3a - e and 4. The piperidines 7a - c were obtained from 1 and primary alkylamines, whereas the 1,4-diazepine derivative 10 was obtained from 1 and ethylenediamine. Treatment of the bis-base 1,4-di[β -(N-morpholino)propionyl]benzene bis(hydrochloride) (11) with primary arylamines gave the corresponding bis-(sec-arylamines) 12a - b, whereas its reaction with ophenylenediamine afforded the bis[1,5-benzodiazepine] ring system 14. The synthesis of the diazacyclophane ring system 15 has been achieved by treating 11 with piperazine. Attempted synthesis of 4- aza-[7]-paracyclophane (16) from 11 and benzylamine led to 17. The reaction of 1 or 11 with phenylhydrazine gave the 2-pyrazolines 18 and 19. Treatment of 3 or 4 with phenylhydrazine and formaldehyde afforded the 2H-1,2,4-triazepines 20a - c and the bis[2H-1,2,4-triazepine] ring system 21.