bluuebunny/crossref_metadata_2025 huggingface dataset:
Notizen: Deoxycyclopaldic Acid and Cyclopaldic Acid, Plant Growth Regulators, Produced by Penicillium sp.
Authors: Shimada A. , Nakaya K. , Takeuchi S. , Kimura Y.
Published: August 2018

Deoxycyclopaldic acid (1) and cyclopaldic acid (2) were isolated from cultures of the fungus Penicillium sp. as plant growth regulators and their structures were established by spectroscopic evidence. Deoxycyclopaldic acid was found in nature for the first time. The biological activities of 1 and 2 have been examined using bioassay methods with lettuce and rice seedlings.
Platinum(II) and Palladium(II) Dichalcogenolene Complexes Containing the Ligand Tri(1-cyclohepta-2,4,6-trienyl)phosphane. Molecular Structure, Intramolecular Dynamics in Solution, and the Absolute Signs of Coupling Constants 1J(195Pt, 77Se) and 2J(77Se, Pt, 31P)
Authors: Herberhold Max , Schmalz Thomas , Milius Wolfgang , Wrackmeyer Bernd
Published: August 2018

Tri(1-cyclohepta-2,4,6-trienyl)phosphane, P(C7H7)3 (1), serves as a bidentate chelatinglig and [P] in platinum(II) and palladium(II) complexes. Here the synthesis of the four dichalcogenolene complexes [P]M[E2C2(CO2Me)2] (4) (M = Pt) and 5 (M = Pd) with E = S (a) and Se (b) from the reaction of the respective dicyclopentadienyltitanium dichalcogenolenes, Cp2Ti[E2C2(CO2Me)2], and [P]MCl2 with M = Pt (2) and Pd (3) is reported. At room temperature, the complexes 4 and 5 are fluxional with respect to the NMR time scale, and the nature of the dynamic process is discussed. The complexes have been characterised by 1H, 13C, 31P, 77Se and 195Pt NMR spectroscopy. The signs of the coupling constants 1J(195Pt, 77Se) (< 0) and 2J(77Se, 31P) (> 0) were obtained by selective 31P{195Pt} and 31P{77Se} spin tickling experiments. The crystal structure of 4b was determined by X-ray analysis.
S-, X-, Q- undW-Band-Pulver-EPR-Untersuchungen am mononuklearen AuII-Komplex [AuII([9]anS3)2](BF4)2 / S-, X-, Q- und W-Band Powder-EPR Investigations on the Mononuclear AuII-Complex [AuII([9]aneS3 )2](BF4)2
Authors: Ihlo Lars , Kampf Michael , Böttcher Rolf , Kirmse Reinhard
Published: August 2018

Powder-EPR-studies at T = 295, 130 and 13 K of the thiacrown ether AuII complex [AuII([9]aneS3)2](BF4)2 diamagnetically diluted by the corresponding ZnII complex are reported. Due to the small anisotropy of the g and the 197Au hyperfine tensor AAu, a large 197Au quadrupole interaction and the noticeable linewidts, the powder spectra show a very complex pattern. Using S-band (2.4 GHz), X-band (9.5 GHz), Q-band (35 GHz) and W-band (94 GHz) frequencies the spectra could be analysed successfully. The spectra were simulated with a computer program which diagonalizes the spin-Hamiltonian matrix exactly. According to EHT-MO calculations most of the spin-density is located in an AuS4 unit of the distorted AuS6 unit.
Supersilyliertes Ammoniak und supersilyliertes Hydrazin: Synthese, Struktur und Eigenschaften / Supersilyl Ammonia and Supersilyl Hydrazine: Synthesis, Structure and Properties
Authors: Lerner Hans-Wolfram , Wiberg Nils , Bolte Michael , Nöth H. , Knizek J.
Published: August 2018

An excellent supersilylation agent, supersilyl triflate, tBu3SiO3SCF3, is easily obtained from tBu3SiH and CF3SO3H. Supersilyl triflate, tBu3SiO3SCF3, reacts with lithium amide or lithium hydrazide to form the supersilyl amine, tBu3SiNH2, or the supersilyl hydrazines, tBu3SiNHNH2 and tBu3SiNH-HNSitBu3, respectively. The structures of supersilyl triflate, tBu3SiO3SCF3, and bissupersilyl hydrazine, tBu3SiNH-HNSitBu3, have been determined by X-ray structure analysis.
Synthesis and Characterization of Mn6(PO4)4·H2O, a New Metal(II) Phosphate Hydrate
Authors: Stock N.
Published: August 2018

The new manganese phosphate hydrate,Mn6(PO4)4·H2O, has been obtained as a single phase product using hydrothermal methods and the structure has been determined by single crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group Cc with a = 934.18(10), b = 1743.68(18), c = 815.15(8) pm, β = 92.616(2)°, V = 1326.4(2)·106 pm3, Z = 4, and the refinement led to R1 = 0.0281 and Rw2 = 0.0728 (all data). The structure is composed of [PO4] and [MnOx] polyhedra (x = 6, 7) and might be described as a distorted primitive hexagonal packing of [PO4] tetrahedra which are held together by Mn2+ ions partially located in distorted trigonal prismatic positions. This leads to a dense three-dimensional framework structure. Magnetic susceptibility measurements verified the presence of high-spin Mn2+ ions and thermogravimetric data confirm the chemical composition deduced from the single crystal structure determination.
Magnesium Anthranilate Dihydrate
Authors: Wiesbrock Frank , Schier Annette , Schmidbaur Hubert
Published: August 2018

The reaction mixture of magnesium chloride with two equivalents of potassium anthranilate [K+ Anth-] in water gives on cooling to 0 °C a 60% yield of a precipitate which after drying in a vacuum has the composition [Mg(H2O)6](Anth)2 (1). Recrystallization from hot water affords an octahydrate identified as [Mg(H2O)6](Anth)2(H2O)2 (2) in a single crystal X-ray diffraction study. Contrary to findings for the related calcium, strontium and barium compounds, in the magnesium compound the anthranilate anions are not part of the coordination sphere of the metal atom. Thermal degradation of 1 or 2 at 125 °C gives the anhydrous product [Mg(Anth)2], 3. Alternative preparative routes employed in previous studies gave only anhydrous material. The result of the present investigation confirms the outstanding stability of the hexa(aquo) complex of magnesium, as compared to the hydrates of the larger alkaline earth metals, in the presence of potential bioligands.
Synthesis and Structural Characterization of Aminoalkanol Derivatives of 2,3-Dihydro-2,2-dimethyl-7-benzofuranol with an Expected β-Adrenolytic and / or Anxiolytic Activity
Authors: Kossakowski Jerzy , Hejchman Elżbieta , Wolska Irena
Published: August 2018

A series of fifteen new N-substituted derivatives of 2,3-dihydro-2,2-dimethyl-7-benzofuranol have been prepared and studied by IR and 1H NMR spectroscopy. In addition the crystal structures of 7-[3-[4-(4-fluorophenyl)-1-piperazinyl]propoxy]-2,3-dihydro-2,2-dimethylbenzofuran (16), 7-[3-(4-phenyl-1-piperazinyl)propoxy]-2,3-dihydro-2,2-dimethylbenzofuran (18) and 7-[3-(4-benzyl-1-piperazinyl)propoxy]-2,3-dihydro-2,2-dimethylbenzofuran (20) have been solved by X-ray structure analysis of single crystals. The crystals of two of them (16 and 18) are isostructural and there are only small differences between their molecular geometries. Greater differences are observed in the crystal structure of the compound 20 due to the presence of a benzyl fragment instead of a phenyl one. The compound 10 (7-(3-t-butylamino-2-hydroxypropoxy)- 2,3-dihydro-2,2-dimethylbenzofuran hydrochloride), screened for basic parameters of rats circulatory system, displayed an effect of decreasing of arterial blood pressure and heart rate
Novel Tandem Cyclisations at the Piperazinedione Ring via Cope Rearrangement
Authors: Jin Shangde , Liebscher Jürgen
Published: August 2018

Novel rearrangements of 3-ylidene-piperazine-2,5-dione (1) were achieved affording Cope rearrangement products 3 and 4 under neutral conditions or tricyclic piperazine-2,5-diones 5, rac-6 and 7 by additional tandem cyclisation in formic acid. Cope rearrangement products 3 and 4 were transformed into new quaternary α-amino acids 9 and 11 by hydrogenation and hydrolysis.
Enaminosulfones from 3-Trifloxypropene Iminium Salts: A 1,5(O→C) Trifluoromethylsulfonyl Shift
Authors: Neumann Ralf , Herz Hans-Georg , Maas Gerhard
Published: August 2018

Treatment of semicyclic 3-trifloxypropene iminium triflates 4a -c,e,f, in which the iminium function is part of a six-membered ring, with a polymer-supported tertiary amine leads to 3- [(trifluoromethyl)sulfonyl]-1,4,5,6-tetrahydropyridines 7.Related five- and seven-membered cyclic iminium salts do not react to give the corresponding enaminosulfones.
Dehydrierung cyclischer tertiärer Amine unter Reaktionsbeteiligung von enantiomeren nucleophilen Nachbargruppen / Dehydrogenation of Cyclic Tertiary Amines with Neighbouring of Enantiomeric Nucleophiles
Authors: Möhrle Hans , Berkenkemper Thomas
Published: August 2018

For stereochemical investigation of their dehydrogenation, the enantiomers of the aminoalcohols 1, 2, and 3 were prepared from optically active sources, while the enantiomers of the diamines 8 and 9 were available by resolution of the racemates.T he pure antipodes of 1, 2, and 3 reacted with mercury(II)-EDTA by a twofold dehydrogenation via intermediate participation of the neighbouring alcoholic group to the optically active lactams 5, 6, and 7 under complete retention of configuration.In the same manner the diamines 8 and 9 generated by four electron withdrawal the cycloamidines 10 and 11.
Transition Metal Complexes of Derivatized Chiral Dihydro-1,2,4-triazin-6-ones, Part IV [1]. Synthesis and Structural Characterization of a Copper(II) Complex of (L)-3-Acetyl-5-benzyl-1-phenyl-4,5-dihydro-1,2,4-triazin-6-one Oxime
Authors: El-Abadelah Mustafa M. , Abushamleh Ahmad S. , Mössmer Cäcilia M. , Voelter Wolfgang
Published: August 2018

Reaction of (L)-3-acetyl-5-benzyl-1-phenyl-4,5,-dihydro-1,2,4-triazine-6-one oxime (1) with copper acetate afforded the complex 5 in high yield. Single crystal X-ray structural analysis of 5 revealed a square-pyramidal geometry around the copper ion where the two oxime ligands are coordinated symmetrically to the Cu atom. The apex of the square-pyramid is occupied by a chloride ligand with the copper atom roofed above the center of the plane of the four coordinating nitrogens by about 0.22 Å . MS-FAB, magnetic and other analytical data are in accord with this solid-state structure.
Preparation, Structure and Optical Properties of [CH3SC(NH2)2]3SnI5, [CH3SC(NH2)2][HSC(NH2)2]SnBr4, (CH3C5H4NCH3)PbBr3, and [C6H5CH2SC(NH2)2]4Pb3I10
Authors: Raptopoulou C. P. , Terzis A. , Mousdis G. A. , Papavassiliou G. C.
Published: August 2018

The preparation, crystal structure and optical absorption spectra of [CH3SC(NH2)2]3SnI5 (1), [CH3SC(NH2)2][HSC(NH2)2]SnBr4 (2), (CH3C5H4NCH3)PbBr3 (3), and [C6H5CH2SC-(NH2)2]4Pb3I10 (4) are reported. The compounds 1, 2, 3 consist of MX6-octahedra (M = Sn, Pb, X = I, Br) forming one-dimensional single chains (compounds 1, 3) or double chains (compound 2). The compound 4 forms a two-dimensional inorganic network via corner sharing of three face sharing octahedral units. Because of their low-dimensional character, a blue shift of the excitonic absorption bands, in comparison to those of higher dimensionality systems, is observed.
γ-Oxo Carboxylic Acids in Heterocyclic Synthesis, III. Synthesis of Biologically Active 4-Benzylamino-6-(5,5-dioxodibenzothiophen- 2-yl)-2,3,4,5-tetrahydropyridazin-3-ones
Authors: Wasfy Ashraf A. F. , Arief Mohamed M. H. , Amine Mahassen S. , Donia Shafey G. , Aly Aly A.
Published: August 2018

α-Benzylamino-β-(5,5-dioxodibenzothiophen-2-carbonyl)propionic acid (1) has been synthesized by treating the corresponding β-aroylacrylic acid with benzylamine in dry benzene. On treatment with hydrazine hydrate the keto acid 1 furnishes the corresponding pyridazinone derivative 2. The behaviour of 2 towards carbon electrophiles, namely, ethyl chloroacetate, acrylonitrile, formaldehyde and secondary amines (under Mannich reaction conditions), aromatic aldehydes and carbon nucleophiles, namely, POCl3/PCl3 and P2S5 has been investigated. The 3-chloropyridazine derivative 13 reacts with hydrazine hydrate to give the 3-hydrazino derivative 14. On treatment with ethyl acetoacetate and/or acetylacetone the hydrazine 14 undergoes cyclization to afford pyrazolone derivative 16 and 3-(3,5-dimethylpyrazol- 1-yl)pyridazine derivative 17, respectively. On reaction with acetylhydrazine in boiling butanol and/or sodium azide in DMF the 3-chloropyridazine derivative 13 affords the triazolo[4,3-b]pyridazine 18 and the tetrazolo[1,5-b]pyridazine 19, respectively. The anti-microbial activity of the synthesized derivatives has been investigated.
Improved Synthesis of HOPh2Si-SiPh2OH and Crystal Structure Analyses of HOPh2Si-SiPh2OH and HOPh2Si-SiPh2-O-Ph2Si-SiPh2OH·1/2C6H6
Authors: Tacke Reinhold , Heermann Joachim , Penka Martin , Richter Ingo , Wagner Brigitte
Published: August 2018

1,1,2,2-Tetraphenyldisilane-1,2-diol (3) was prepared in a two-step synthesis, starting from 1,2-bis(diethylamino)-1,1,2,2-tetraphenyldisilane (1). Treatment of 1 with acetyl chloride yielded 1,2-dichloro-1,1,2,2-tetraphenyldisilane (2), which upon hydrolysis gave 3 (total yield 83%). Compounds 2 and 3 were characterized by elemental analyses (C,H) and solution NMR experiments (1H, 13C, 29Si; CDCl3). In addition, compound 1 and its condensation product, 1,5-dihydroxy-1,1,2,2,4,4,5,5-octaphenyl-3-oxa-1,2,4,5-tetrasilapentane (4; studied as the hemibenzene solvate 4ּ1/2C6H6), were structurally characterized by single-crystal X-ray diffraction.
Synthesis, Structure, and Magnetic Properties of CeNiIn2
Authors: Zarembaa Vasyl’ I , Kalychak Yaroslav M , Tyvanchuk Yuriy B , Hoffmann Rolf-Dieter , Möller Manfred H , Pöttgen Rainer
Published: August 2018

Single crystals of the ternary indide CeNiIn2 were synthesized from an indium flux. An arc-melted button of the starting composition CeNiIn2 was annealed in a zirconia crucible with a slight excess of indium at 1200 K followed by slow cooling (5 K/h) to 870 K. The new indide has been investigated by X-ray diffraction on powders and single crystals: PrNiIn2 type, Cmcm, a = 440.78(4), b = 1834.3(1), c = 2178.8(2) pm, wR2= 0.0753 for 1471 F2 values and 66 variable parameters. The structure contains three crystallographically independent nickel positions which have a distorted trigonal prismatic coordination. The CeNiIn2 structure is related to the MgCuAl2 structure by chemical twinning. The shortest interatomic distances occur for Ni-In and In-In contacts. The nickel and indium atoms form a complex three-dimensional [NiIn2] network in which the cerium atoms fill distorted pentagonal channels. Magnetic susceptibility measurements indicate Curie-Weiss behavior with an experimental magnetic moment of 2.44(3) μB/Ce atom. At 3.4(3) K CeNiIn2 orders ferro- or ferrimagnetically. The experimental saturation magnetization at 2K and 5.5 T is 0.95(2) μB/Ce.
Ternary Indides LnRhIn2 (Ln = La, Ce, Pr, Nd, Sm) with MgCuAl2 Type Structure
Authors: Zaremba Vasyl’ I , Dubenskiy Vitaliy P , Pöttgena Rainer
Published: August 2018

The ternary indides LnRhIn2 (Ln = La, Ce, Pr, Nd, Sm) were synthesized by arc-melting of the elements under an argon atmosphere and subsequent annealing at 870 K. The samples have been investigated by X-ray diffraction on powders and single crystals: MgCuAl2 type, Cmcm, a = 448.2(1), b = 1025.7(1), c = 795.1(1) pm, wR2 = 0.0372, 228 F2 values, 16 variables for LaRhIn2, a = 446.0(1), b = 1017.3(2), c = 792.7(1) pm for CeRhIn2, a = 444.03(6), b = 1013.1(1), c = 792.5(1) pm for PrRhIn2, a = 442.49(5), b = 1012.7(1), c = 789.3(1) pm for NdRhIn2, and a = 438.1(1), b = 1009.3(1), c = 788.3(1) pm, wR2= 0.0414, 304 F2 values, 16 variables for SmRhIn2. Geometrical motifs of these structures are tricapped trigonal prisms around the rhodium atoms. The shortest interatomic distances were observed for the Rh-In contacts: 280-282 pm for LaRhIn2 and 276-279 pm for SmRhIn2. Together, the rhodium and indium atoms build a three-dimensional [RhIn2] polyanion in which the lanthanoid atoms fill distorted pentagonal channels. According to one short La-Rh (282 pm) and Sm-Rh (284 pm) distance one can assume strong bonding of the lanthanoid atoms to the polyanion.
Preparation and Crystal Structure of Bis(isocyanide)gold(I) Bis(phenylene-1,2-dithiolato)aurates(III)
Authors: Ehlich Hendrik , Schier Annette , Schmidbaur Hubert
Published: August 2018

The reaction of (isocyanide)gold(I) chlorides [(RNC)AuCl, R = tBu, cHex] with phenylene- 1,2-dithiol and sodium methoxide (molar ratio 2:1:2) in methanol / dichloromethane leads to the formation of deep green mixed-valent salts [(RNC)2Au]+[Au(S2C6H4)2]- in ca. 35% yield. As determined by single crystal X-ray diffraction methods, the two compounds have entirely different supramolecular structures. For R = tBu stacked planar anions and rod-like cations form alternating layers, while for R = cHex alternating cations and anions are arranged in chains with long S- -Au contacts [3.422 Å].
Valence Bond Studies of N5
+
Authors: Harcourta Richard D. , Klapötkeb Thomas M.
Published: August 2018

The results of STO-6G valence-bond studies are reported for the six π-electrons of C2v symmetry N5
+, with π-electron core charges determined from the valence bond structures. Important types of canonical Lewis structures are calculated to carry either three atomic formal charges, arranged spatially as (+), (-) and (+) , as in

or a single (+) atomic formal charge, as in the “long-bond” structure

When localized molecular orbitals are used to accommodate bonding electrons between pairs of adjacent atoms, each of these types of Lewis structures, and others, are components of the increased-valence structure

whose bond properties are in qualitative accord with experimental estimates of the bond lengths for N5
+. Consideration is also given to other types of valence bond representations for N5
+, and the results of MP2 molecular orbital calculations for the hypothetical N8
2+ are reported. For the latter species, a stable energy minimum with C2 symmetry is obtained. Its bond lengths are related to those implied by a Lewis-type valence-bond structure
New Phosphorus-Containing Polycylic Large-Ring Systems Involving Heteroatoms
Authors: Lu Yingzi , Freytag Matthias , Jones Peter G. , Schmutzler Reinhard
Published: August 2018

The [1+1] cyclocondensation of the bis-PCl species 1,2-bis(benzo-1-methyl-2-chloro- 1,3,2-diazaphosphorin-4-on-3-yl)ethane 1 and 1,3-bis(benzo-1-methyl-2-chloro-1,3,2-diazaphosphorin- 4-on-3-yl)propane 2 with the 1,2-benzenediol bis(trimethylsilyl) ether 3a and 2,3- naphthalenediol bis(trimethylsilyl) ether 3b gave the symmetrical phosphorus-containing largering systems 4 - 7 in moderate yield. The phosphoryl compounds 8 - 11 were obtained by the oxidation of 4 - 7 with (H2N)2C(:O) H2O2. Oxidation of 6 and 7 with elemental sulfur furnished the thiophosphoryl compounds (12 and 13). All new compounds formed in the reactions were characterized unambiguously by NMR spectroscopy, mass spectrometry, and elemental analysis. For compounds 6, 9, 10, 11 and 12, X-ray crystal structure determinations were conducted. The compounds with ten-membered rings show approximate (6, 12) or exact (10) twofold symmetry. In each of the compounds 9 and 11 the two six-membered heterocycles are appreciably different; one is approximately planar, whereas in the other, phosphorus lies outside the plane of the other five atoms
Eine einfache Synthese von 1,3-Dihydro-1,3-diborapentafulven-Derivaten / A Convenient Synthesis of 1,3-Dihydro-1,3-diborapentafulvene Derivatives
Authors: Bayer Michael J. , Siebert Walter
Published: August 2018

Reaction of 3,3-dimethyl-1-butynyllithiumwith boron trichloride followed by hydroboration with HBCl2 leads to 1,1-bis(dichloroboryl)-3,3-dimethylbutene (4a). Halogen exchange with boron triiodide yields the corresponding tetraiodide 4b, which undergoes a redox reaction with 3-hexyne to give the 1,3-dihydro-1,3-diborapentafulvene 3b. Its 1,3-dimethyl derivative 3c is less stable and rearranges to nido-C4B2 carboranes as well as to polymeric products. Hydroboration of 3c with HBEt2 results in the formation of the nido-C3B3 carborane 6c. The reaction of 3c with Mo(CO)6 yields the 1,3-diborapentafulvene complex 7c.
Darstellung und Thermolyse tert-butylsubstituierter Silatetrazoline – Erzeugung der Silanimine tBu2Si=N-SiXtBu2 (X = F, Cl, Br, tBu) Synthesis and Thermolysis of the tert-Butyl-Substituted Silatetrazolines – Formation of the Silanimines tBu2Si=N-SiXtBu2 (X = F, Cl, Br, tBu)
Authors: Lerner Hans-Wolfram , Wiberg Nils , Polborn K.
Published: August 2018

The silanimine tBu2Si=N-SitBu3 reacts with the silyl azides tBuMe2SiN3 or tBu2SiXN3 (X = H, Me, F, Cl, Br) to form the corresponding tert-butyl-substituted 1-tri-tert-butylsilyl-4-triorganosilyl- 5,5-di-tert-butylsilatetrazolines. The silatetrazolines with chloro-di-tert-butylsilyl and bromo-di-tert-butylsilyl substituents can also be synthesized by treating two equivalents of tBu2SiXN3 (X = Cl, Br) with the silanide tBu3SiNa. In the thermolysis of the silaterazolines the silanimines tBu2Si=N-SiXtBu2 (X = F, Cl, Br, tBu) and silyl azides are formed in a first-order process. The silanimines tBu2Si=N-SiXtBu2 (X= F, Cl, Br, tBu) have been trapped with acetone by en-reaction. The structure of (dimethyl-tert-butylsilyl)-substituted silatetrazoline has been determined by X-ray structure analysis.
A New Trinuclear Cyano-Bridged Sr-Fe(III) Complex, [Sr2(phen)4(H2O)3(NO3)Fe(CN)6] · H2O
Authors: Datta Amitabha , Karan Nirmal Kumar , Mitra Samiran , Malik K. M. Abdul
Published: August 2018

1

A new cyano-bridged trinuclear complex [Sr2(phen)4(H2O)3(NO3)Fe(CN)6] · 1.25 H2O () (where phen = 1,10-phenanthroline) has been synthesised and its crystal structure determined. The structure features a central [Fe(CN)6]3- unit that links a [Sr(phen)2(OH2)2]2+ dication and a [Sr(phen)2(OH2)(NO3)]+ monocation via two trans cyanide bridges. In the dicationic part, the Sr centre achieves a pentagonal bipyramidal geometry whereas in the monocationic part, the Sr centre shows a square antiprismatic geometry. The presence of an extensive network of hydrogen bonds imparts the overall stability to the system.
Synthese difluorierter cyclopropanoider Nucleosidanaloga/Synthesis of Difluorinated Cyclopropanoid Nucleoside Analogues
Authors: Csuk René , Thiede Gisela
Published: August 2018

Starting from (2,2-difluorocyclopropyl)methanol a novel class of difluorinated cyclopropanoid nucleoside analogues containing two hydroxymethyl side chains was synthesized in a straightforward way. Several of the final compounds could be obtained in an enantiomerically pure form by HPLC using chiral stationary phases.
Bischler-Napieralski Synthesis of Some New Pyrazole-Fused β-Carbolines
Authors: Abu-Safieh Kayed A. , El-Abadelah Mustafa M. , Sabri Salim S. , Voelter Wolfgang , Mössmer Cäcilia M. , Stroebele Markus
Published: August 2018

3-(4-Acylaminopyrazol-5-yl)-4-methylindoles (13a,b), under Bischler-Napieralski reaction conditions, undergo cyclization at the pyrrolic carbon-2 with ultimate formation of the corresponding pyrazolo[3,4:5′,6′]pyrido[3,4-b]indoles (14a,b) as evidenced by crystal structure analysis of 14a.
Synthesis and X-Ray Crystal Structure Determination of Thiotrithiazyl Iododichloride, S4N3ICl2
Authors: Irsen Stephan H. , Dronskowski Richard
Published: August 2018

Thiotrithiazyl iododichloride, S4N3ICl2, has been synthesized from molecular S4N4 and liquid ICl and structurally characterized by an X-ray Rietveld refinement. S4N3ICl2 crystallizes in the monoclinic system (P21/c, a = 611.548(7), b = 877.336(8), c = 1770.12(2) pm, β = 92.3357(7)°, Z = 4), follows the crystal-chemical motif (S4N3
+)(ClICl−), and is thus isotypic with (S4N3
+ )(Br3
− ). The crystal structure contains a planar S4N3
+ ring and a linear ClICl− unit.
Transition Metal-Gallium Ordering In HfCoGa2 And HfNiGa2
Authors: Schlüter Martin , Heying Birgit , Pöttgen Rainer
Published: August 2018

The gallides HfCoGa2 and HfNiGa2 were synthesized by arc-melting of the elements and subsequent annealing in glassy carbon crucibles. Their structures have been reinvestigated by X-ray diffraction on powders and single crystals: I4mm, a = 1222.4(1), c = 812.0(1) pm, wR2 = 0.0766, 1464 F2 values, 64 variables, BASF = 0.41(2) for HfCoGa2 and a = 1224.0(2), c = 809.3(2) pm, wR2 = 0.0609, 1499 F2 values, 63 variables for HfNiGa2. In contrast to a previous investigation (Dopov. Akad. Nauk Ukr. RSR, Ser. A, 51 (1988)) we observe a fully ordered arrangement of the transition metal and gallium atoms. The crystal chemistry of these gallides is briefly discussed.
Hydroxyurea Analogues of Fosmidomycin
Authors: Kurz Thomas , Geffken Detlef , Wackendorff Claudia
Published: August 2018

Benzyloxyureas (4) have been prepared by reactions of diethyl 3-benzyloxyamino-propyl-phosphonate (3) with isocyanates, potassium cyanate or 1,1’-carbonyldiimidazole / methylamine. Conversion of phosphonic esters 4 into phosphonic acids 6 by means of bromotrimethylsilane and catalytic hydrogenation of 4, 6 afforded the target compounds 5, 7.
Novel Asymmetrical Dianionic Polyimido-Sulfur(IV)-Ylides
Authors: Selinka Carola , Stalke Dietmar
Published: August 2018

Sulfurdiimides RN=S=NR react in donating solvents with two equivalents of lithiumalkyls to give the dimeric C,N-dilithium-methylenediimidosulfite solvent adducts [(Et2O)Li2{H2CS-(NSiMe3)(NtBu)}]2 (1) and [(thf)Li2{H8C4S(NtBu)2}]2 (2). Firstly, addition of a lithiumalkyl to sulfurdiimide gives the diimidosulfinates [RS(NR')2]- (1: R = Me, R′ = tBu, SiMe3; 2: R = nBu; R′ = tBu) while in a second step the α-carbon atom in R is metalated with one equivalent of lithiumalkyl to give the asymmetric S-ylides. The reaction of 3-bromothiophene with one equivalent of nBuLi and one of sulfurdiimide tBuN=S=NtBu resulted in the dilithium-3-thiophenylenediimidosulfite [(thf)Li2{(SC4H2)S(NtBu)2}]2 (3). It can be regarded

as the first example of a dianionic S(IV)-β-ylide. This class of compounds can be rationalised as sulfite analogues, where two oxygen atoms are isoelectronically replaced by a NR group each and the remaining oxygen atom is replaced by a CR2 group. The rich coordination chemistry of the triimidosulfites is extended by the introduction of a hard carbanionic centre.
Access to Orthogonal Protected Phenols – Synthesis of a Silylated Quinol
Authors: Siddiqi Shahzad A. , Heckrodt Thilo J.
Published: August 2018

Herein we describe the synthesis of t-butyldimethylsilyl protected quinol (9), using an oxidation/ reduction sequence to create the desired orthogonality. The title compound acts as a synthetic equivalent for a quinone, required in the total synthesis of Elisabethin A. It contains a masked quinone and therefore is a suitable precursor for the quinone moiety of this diterpenoid.
On Attempts to Synthesize Lanthanide Complexes of the Dianionic Fluorenyl-alkoxo Ligand [C13H8-cyclo-C6H10-O]2-. Crystal Structure of (C13H9-cyclo-C6H10-O)LaI2(DME)2
Authors: Trifonov Alexander A. , Bochkarev Mikhail N. , Schumann Herbert , Dechert Sebastian
Published: August 2018

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.
Zinc (Hydrogen-β-glutamate)-chloride Hydrate [Zn (β-GluH)Cl(H2O)], a One-dimensional Coordination Polymer
Authors: Wiesbrock Frank , Schmidbaur Hubert
Published: August 2018

Zinc (hydrogen-β -glutamate) chloride hydrate is readily prepared from equimolar quantities of [Zn (β -GluH)2] and ZnCl2 in water. The crystal structure shows a coordination polymer with zinc atoms bridged by the 3-ammonio-glutarate ligand. The tetrahedral coordination sphere of the metal atom is completed by the chloride anion and the water molecule.
The Effect of High Energy Milling on the Solid State Synthesis of MnFe2O4 from Mixtures of MnO-Fe2O3 and Mn3O4-Fe2O3
Authors: Berbenni V. , Marinia A. , Profumo A. , Cucca L.
Published: August 2018

A thermal treatment at 900°C (under nitrogen) of a milled mixture MnO-Fe2O3 yields MnFe2O4 mainly as the product of the reaction between Mn3O4 (produced by ball milling) and Fe2O3. Under the same experimental conditions but starting from an unmilled MnO- Fe2O3 mixture, the formation of MnFe2O4 is only partial and occurs through Mn3O4 (formed by oxidation of MnO). The same thermal treatment (900°C under nitrogen) of a milled Mn3O4-Fe2O3 mixture yields MnFe2O4 mainly as the product of the reaction between Mn3O4 and Mn2O3/MnO2 (the higher Mn oxides being produced by ball milling) and Fe2O3. The effect of high energy milling is more pronounced in the case of the Mn3O4-Fe2O3 system since no MnFe2O4 formation is observed when starting from a physical mixture.
Ruthenocene mit sterisch anspruchsvollen Cyclopentadienylliganden
Authors: Schumann Herbert , Stenz Susanne , Mühle Stefan H.
Published: August 2018

1-tert-Butyl-2,4-cyclopentadiene (1), 1,3-di(tert-butyl)-2,4-cyclopentadiene (2), 1-ethyl-2,3,4,5- tetramethyl-2,4-cyclopentadiene (3), 1-iso-propyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (4), 1- tert-butyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (5), and 1-phenyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (6) react with n-butyl lithium followed by tributyltin chloride to give the corresponding tributyl(cyclopentadienyl)stannanes Bu3SnCp# 1a to 6a. The reactions of 1a to 6a with Ru(COD)Cl2 result in the formation of the corresponding ruthenocenes RuCp2
# 1b to 6b. Ru(C5H3Ph2)2 (7b) is prepared from [Ru(p-cymol)Cl2]2 and Na[C5H3Ph2]. The 1H and 13C NMR spectra of the new stannanes 1a to 6a and the ruthenocenes 1b to 7b as well as the single crystal X-ray structure of 4b are reported and discussed.
Synthesis and Crystal Structure of the Germatrane E-N(CH)2CH2O3GeC(Br)=C(Br)Ph
Authors: Selina Anastasia A. , Karlova Sergey S. , Harms Klaus , Tyurina Daniil A. , Oprunenko Yuri F. , Lorberth Jörg , Zaitseva Galina S.
Published: August 2018

The reaction of (phenylacetylenyl)triethoxygermane, (EtO)3GeC≡CPh (3), with bromine in CHCl3/CCl4 solution leads to a mixture of Z- and E- (EtO)3GeC(Br)=C(Br)Ph (4) in the ratio Z/E = 3/1. Treatment of this product with N(CH2CH2OH)3 affords a mixture of Z- and EN(CH2CH2O)3GeC(Br)=C(Br)Ph (2) in high yield. Compound E-2 was isolated in 16% yield. The molecular composition and the structure of all new compounds have been established by elemental analyses, 1H and 13C NMR spectroscopy. The crystal structure of E-2 is reported. The possible reasons for the different Z/E ratios in the products of the bromination of 3 and N(CH2CH2O)3GeC≡CPh (1) are discussed using DFT calculations.
Molten Gallium as a Non-Reactive Solvent: Synthesis of the Silicides RE2Ni3+xSi5-x (RE = Sm, Gd and Tb)
Authors: Zhuravleva Marina A. , Kanatzidis Mercouri G.
Published: August 2018

The use of molten Ga as a non-reactive solvent for the synthesis of intermetallic silicides was demonstrated on the family RE2Ni3+xSi5-x (RE = Sm, Gd and Tb). The structure of Sm2Ni3+xSi5-x was solved from single crystal X-ray data in the orthorhombic space group Ibam, Z = 4, cell parameters a = 9.6396(12); b = 11.3219(14); and c = 5.6967(13) Å . The refinement based on the full-matrix least-squares on F2
o [I > 2σ(I)] converged to final residuals R1/wR2 = 0.0206/0.0492. The structure of RE2Ni3+xSi5-x is related to the U2Co3Si5 structure type; however, discrepancies exist between the solution obtained for RE2Ni3+xSi5-x and that reported for U2Co3Si5. The magnetic properties studied on Tb2Ni3+xSi5-x indicate an antiferromagnetic ordering of magnetic moments centered at Tb ions at 13 K, and Curie-Weiss behavior at high temperatures with the effective moment close to that of free Tb3+ ion.
Erstmalige Charakterisierung der Ammoniak-Proton-Komplexe [(NH3)3H]+ und [(NH3)4H]+ in den Kristallstrukturen von (NH4)3AsS4 · 5 NH3 und (NH4)3SbS4 · 8 NH3 / First Characterization of the Ammonia-Proton-Complexes [(NH3)3H]+ and [(NH3)4H]+ in the Crystal Structures of (NH4)3AsS4 · 5 NH3 and (NH4)3SbS4 · 8 NH3
Authors: Roßmeier Thomas , Korber Nikolaus
Published: August 2018

The compounds (NH4)3AsS4· 5 NH3 (1) and (NH4)3SbS4· 8 NH3 (2) were prepared by the reaction of Na3AsS4 and Na3SbS4 with a proton-charged ion exchange material in liquid ammonia and characterized by low temperature single crystal X-ray structure analysis. The ammonium-ammoniates show H3N-H···N-hydrogen bonds between the ammonium ion and ammonia molecules ranging from 1.86 to 2.55 Å (DHA-angles: 145 - 173°) and H3N-H···S-bonds to the thioanions between 2.36 and 2.97 Å (DHA-angles: 130 - 176°). The former of the interactions are responsible for the formation of [(NH3)2H]+, [(NH3)3H]+ and [(NH3)4H]+-complexes, the last two of which were characterized by X-ray analysis for the first time.
A Convenient Regioselective Synthesis of 6-Amino-2-oxo-3,5-pyridinedicarbonitriles
Authors: Girgis Adel S. , Hosni Hanaa M. , Ahmed-Farag I. S.
Published: August 2018

Reaction of cyanoacetohydrazones 3a,b with a variety of arylidenemalononitriles 5a - c under the effect of piperidine basic catalysis afforded exclusively the corresponding 6-amino-1,2-dihydro-1,4- disubstituted-2-oxo-3,5-pyridinedicarbonitriles 6a - f in high regioselectivity. A chemical confirmation for the proposed structure was achieved through the reaction of ylidenes 8 with malononitrile under basic conditions, which yielded the corresponding 6 accompanied with 3. Refluxing 3b in acetic anhydride gave 2-acetyl-3-cyanomethyl-4,5-dihydro-2H-benz[g]indazole (10) as the only isolable product. Single crystal X-ray diffraction of 6e and 10 add conclusive support for the established structures.
Synthesis, Spectroscopic Properties, and Crystal Structure of the Oxonium Acid [H(OEt2)2]+[Ti2Cl9]–
Authors: Rannabauer Stefan , Habereder Tassilo , Nöth Heinrich , Schnick Wolfgang
Published: August 2018

The oxonium acid [H(OEt2)2]+[Ti2Cl9]− (1) was obtained by the reaction of TiCl4 with Et2O in n-pentane and subsequent partial hydrolysis. Suitable single crystals of 1 were obtained by sublimation at 5° C ([H(OEt2)2]+[Ti2Cl9]−, P212121 (no. 19), Z = 4, a = 1101.08(8), b = 1328.4(2), c = 1525.0(2) pm, T = 193(2) K, 4489 independent reflections, 197 parameters, R1 = 0.049). The cation is made up from two independent Et2O molecules and one disordered proton on two split positions. Both ether molecules exhibit a W form, and their molecular planes include an angle of 74.1(7)°. Thus a distorted tetrahedron is formed by the four methyl carbon atoms of the two ether molecules. The distance O···O amounts to 237.7(1) pm. The proton of the cation was characterized both by 1H NMR (CDCl3, T = 23 °C: δ = 11.7 ppm, w1/2 = 100 Hz) and IR spectroscopy (3120 cm−1, ν vbr). The [Ti2Cl9]− ion consists of two face sharing octahedra. 47Ti and 49Ti NMR spectra were recorded in solution (CH2Cl2, T = 23 °C: δ 49Ti = 137 ppm, w1/2 = 175 Hz; δ 47Ti = −124 ppm, w1/2 = 250 Hz). The absence of a signal for TiCl4 at δ 49Ti = 0 ppm indicates the stability of the dinuclear anion in solution.
Asymmetric Catalysis, 154 [1]. New 1,1’-Binaphthyl Ligands for Enantioselective Catalysis
Authors: Brunner Henri , Weber Matthias , Zabel Manfred
Published: August 2018

Chiral binaphthyl compounds, especially those with different substituents in 2- and 2’-position of the binaphthyl system, have gained interest as constituents of successful ligands in various catalytic reactions. Here, we present the synthesis and characterization of new binaphthyl ligands containing oxazoline, cyano and amide substituents in 2’-position in addition to methoxy, hydroxy or amino groups in 2-position. Starting from these compounds new ligands for enantioselective catalysis will be accessible.
Synthesis of Cyclopropanoid Nucleoside Analogues Possessing a Flexible Side Chain
Authors: Csuk René , Kern Anja
Published: August 2018

A novel class of cyclopropanoic nucleoside analogues containing an hydroxyethyl residue instead of a hydroxymethyl side chain has been prepared in an easy sequence. These compounds showed weak antitumor activity. The resolution of the racemates on an analytical scale was performed by HPLC using chiral stationary phases.
Synthesis of Spacered Nucleoside Analogues Comprising a Difluorocyclopropane Moiety
Authors: Csuk René , Thiede Gisela
Published: August 2018

A novel class of difluorinated cyclopropanoic nucleoside analogues containing a propyl spacer between the cyclopropane ring and the heterocycle has been prepared. Some of these compounds showed weak antitumor activity in prelimary screenings. The resolution of these racemic compounds on an analytical scale was performed by HPLC using chiral stationary phases.
Synthesis, Characterisation and Structural Studies of [Zn(phen)3][Fe(CN)5(NO)]·2H2O·0.25MeOH and [(bipy)2(H2O)Zn(μ-NC)Fe(CN)4(NO)]·0.5H2O
Authors: Datta Amitabha , Mitra Samiran , Rosair Georgina
Published: August 2018

Two new bimetallic complexes [Zn(phen)3][Fe(CN)5(NO)] · 2 H2O · 0.25 MeOH, (1) and [(bipy)2(H2O)Zn(μ-NC)Fe(CN)4(NO)] · 0.5 H2O, (2), have been isolated (where phen = 1,10-phenanthroline and bipy = bipyridyl) and characterised by X-ray crystallography [as the 2 H2O · 0.25 CH3OH solvate for (1) and hemihydrate for (2)] infrared spectroscopy and thermogravimetric analysis. Substitution of phenanthroline for bipyridyl resulted in a cyano-bridged bimetallic species rather than two discrete mononuclear metal complexes. The bond angles of Fe-N-O were shown to be practically linear for both 1 [179.2(7)°] and 2 [178.3(3)°], and the Zn atoms have distorted octahedral geometry. The solvent molecules in both crystal lattices take part in forming hydrogen-bonded networks.
Is 2-D Graphite an Ultimate Large Hydrocarbon? IV. Structure and Energy Spectra of Large Polycyclic Aromatic Hydrocarbons with Different Symmetry
Authors: Staykov Aleksandar , Gehrgel Lileta , Dietz Fritz , Tyutyulkov Nikolai
Published: August 2018

The structure and energy spectra of large polycyclic aromatic hydrocarbons (PAHs) with different symmetry and edge structure have been studied by quantum chemical methods. It is shown, that if the electron correlation is taken into account, the energy gap in the spectra of the one-electron excitation ΔE is different from zero as the number of π-centres of the PAHs, N, tends to infinity (N → ∞). Hydrocarbons with different edge structures but with the same symmetry have different energy gaps when N tends to infinity. Hydrocarbons with different symmetry but with the same edge structures have similar energy gap values.
Dawenol, a New Polyene Metabolite from the Myxobacterium
Authors: Söker Udo , Kunze Brigitte , Reichenbach Hans , Höfle Gerhard
Published: August 2018

A group of new polyene metabolites was detected in several crude extracts of the myxobacterium Stigmatella aurantiaca. The main compound dawenol (1) was isolated from cultures of S. aurantiaca, strain DW4/3-1. Its n-eicosaheptaene structure was elucidated by spectroscopic methods.
A Novel Methylene Dithioether as a Ligand: Synthesis and Molecular Structure of a Zinc(II) Complex with N4S2 Coordination Environment
Authors: Hahn F. Ekkehardt , Jocher Christoph , Schröder Henning
Published: August 2018

The octadentate ligand [N(CH2CH2NH2)(CH2CH2CH2OH)(CH2CH2S)]2CH2, (NNOS-232)2CH2, was synthesized accidentally by the reaction of the unsymmetrically substituted tripod [N(CH2CH2NH2)(CH2CH2CH2OH)(CH2CH2SH)], NNOS-232, with dichloromethane in the presence of aluminum hydroxide. Ligand (NNOS-232)2CH2 was reacted with zinc bis(perchlorate) hexahydrate to yield the complex [Zn((NNOS-232)2CH2)](ClO4)2 1 exhibiting a distorted octahedrally coordinated zinc atom in an N4S2 coordination environment, as shown by an X-ray diffraction study.
(1,2-DAPH2)2Ge9(OH)4O18 · 2H2O: A New Microporous Germanate Based on the Interconnection of Ge9O18 Clusters Showing Reversible Water Emission and Uptake
Authors: Pitzschke Dragan , Näther Christian , Bensch Wolfgang
Published: August 2018

Treatment of germanium dioxide with a 33% aqueous solution of 1,2-diaminopropane (DAP) under solvothermal conditions leads to the formation of colourless octahedral crystals of the novel germanate (1,2-DAPH2)2Ge9(OH)4O18 · 2 H2O. The compound crystallises in the orthorhombic space group Pbca, a = 14.4155(10), b = 12.9384(9), c = 14.5417(8) Å,V =2712.2 (3) Å3; Z =4. The structure consists of an anionic [Ge9(OH)4O18]4− framework with isolated [1,2-DAPH2]2+ cations and water molecules in the channels of the structure. The primary building units of the anionic framework are GeO4 tetrahedra, GeO5 trigonal bipyramids, and GeO6 octahedra. The asymmetric unit consists of two GeO5 units sharing a common edge to form a Ge2O8 unit. This Ge2O8 unit is corner-linked to two GeO4 tetrahedra, and finally one GeO4 tetrahedron is connected to a GeO6 octahedron by cornersharing. The connectivity yields a chain-like Ge5O19 fragment as a secondary building unit (SBU). The chain fragments are interconnected with each other forming the three-dimensional framework. Three types of channels with diameters ranging from 5.98 to 8.025 Å intersect the three-dimensional germanate network. Upon heating the compound decomposes in three steps starting at about 125˚C losing the water and the 1,2-diaminopropane molecules.

In situ X-ray diffraction experiments show that the water molecules are removed retaining the integrity of the skeleton of the material. The removal of H2O is accompanied with an anisotropic shrinkage of the structure. The original lattice parameters were obtained after the uptake of water.
Calculated NMR Parameters (Chemical Shifts and Coupling Constants) of Cyclic C4H2 and C4H4 Molecules Containing Carbene Centers, and of Some of their Boron Analoga, Using Density Functional Theory (DFT)
Authors: Wrackmeyer Bernd
Published: August 2018

Singlet state structures of small, cyclic hydrocarbons which can result from the addition of molecular dicarbon (C2) to ethyne (HC≡CH) or ethene (H2C=CH2) have been calculated (B3LYP/6- 311+G(d,p) level of theory), and were found to contain carbene centres. Some structures of analogous boranes (replacement of the carbene centers by BH fragments) were also calculated. The computation of NMR parameters such as chemical shifts δ 13C and δ 11B, and coupling constants 1J(13C,1H), 1J(11B,1H), J(13C,13C) and J(13C,11B) shows that these data can be used for the discussion of the bonding situation. The presence of inverted carbene centers is clearly indicated by the increased 13C nuclear magnetic shielding. Scalar 13C-13C spin-spin coupling involving carbene centers are frequently dominated by spin-dipole and spin-orbital interactions.
A New Triterpenoid Saponin from Ononis spinosa and Two New Flavonoid Glycosides from Ononis vaginalis
Authors: Shaker Kamel H. , Dockendorff Katja , Bernhardt Mirko , Seifert Karlheinz
Published: August 2018

The new triterpenoid saponin 3-O-[α-L-rhamnopyranosyl-(1→2)-β -D-xylopyranosyl-(1→2)- β -D-glucuronopyranosyl]-3β ,22α-dihydroxyolean-13-en-11-one has been isolated from Ononis spinosa. The new flavonoid glycoside 3-O-[2-O-(E)-p-coumaroyl-β -D-galactopyranosyl]-7-O-β - D-glucopyranosylkaempferol and the new pterocarpan glucoside 3,4-di-O-β -D-glucopyranosyl-4- hydroxymedicarpin have been obtained from Ononis vaginalis. The structures were determined primarily by NMR spectroscopy. The assignment of NMR signals was performed by means of 1H-1H COSY, ROESY, TOCSY, HMQC HMQC-COSY and HMBC experiments.
Crystal Growth and Crystal Structure of the Metastable Bismuth Orthoborate BiBO3
Authors: Becker Petra , Fröhlich Roland
Published: August 2018

Single crystals of bismuth orthoborate, BiBO3, were grown from the melt in the system Li2OBi2O3- B2O3 · BiBO3 is confirmed to adopt at least two different structural modifications. The modification BiBO3(I) (corresponding to PDF Nr. 28-0169) crystallizes with space group P21/c. The structure consists of [Bi2O10] groups that are formed by two edge-sharing distorted [BiO6] octahedra and that are interconnected by sharing common corners (oxygen). The [Bi2O10] groups are further sharing corners with planar [BO3] groups giving a three-dimensional framework
Two Ceramides from Tanacetum artemesioides
Authors: Ahmad Viqar U. , Hussain Javid , Hussain Hidayat , Farooq Umar , Akber Erum , Nawaz Sarfraz A. , Choudhary Muhammad I.
Published: August 2018

Two new ceramides have been isolated from Tanacetum artemisioides, besides the known constituents β -sitosterol and β -sitosterol glycoside. The structure elucidation of the isolated new compounds was based primarily on 1D and 2D NMR analysis, including COSY, HMQC, HMBC correlations. The compound 1 and 2 showed inhibitory activity against acetylcholinesterase
Two New Cyclolignan Glycosides from Acanthus ilicifolius
Authors: Wu Jun , Zhang Si , Li Qingxin , Huang Jianshe , Xiao Zhihui , Long Lijuan
Published: August 2018

Two new cyclolignan glycosides, (+)-lyoniresinol 3a-O-α-D-galactopyranosyl-(1 → 6)-β -D-glucopyranoside (1) and (+)-lyoniresinol 2a-O-α-D-galactopyranosyl-3a-O-β -D-glucopyranoside (2) were isolated from the aerial parts of Acanthus ilicifolius. Their structure elucidation is based on the analyses of spectroscopic data
Die Synthese von 2-Methyl-5-phenacyl-1,3,4-thiadiazolen / The Synthesis of 2-Methyl-5-phenacyl-1,3,4-thiadiazoles
Authors: Kantlehner Willi , Haug Erwin , Kinzy Willy , Scherr Oliver , Ivanov Ivo C.
Published: August 2018

Keywords

2,5-Dimethyl-1,3,4-thiadiazole (1a) reacts which aromatic carboxylic acid esters 8a - u in the presence of excessive sodium hydride under condensation to give sodium enolates which afford on hydrolysis the phenacyl-1,3,4-thiadiazoles 9a - u. The action of aromatic carboxylic acid chlorides on 1a in the presence of triethylamine gives rise to the formation of mixtures of diacylated thiadiazole derivatives 16 and 18. In some cases the pure 3-acyl-phenacylidene-2,3-dihydro-1,3,4-thiadiazoles 16 can be isolated. Generally the compounds 16 are rearranged on heating in higher boiling solvents to give the enolbenzoates 18. Hydrolysis of the diacylated thiadiazoles 16 and 18 yields the phenacylthiadiazoles 9a, c, d, g - j, v, w.
Reactions of Quinolizine- and Pyridino[1,2–a]pyrimidine-3-diazonium Tetrafluoroborates with Aliphatic Amines
Authors: Rečnik Simon , Svete Jurij , Stanovnik Branko
Published: August 2018

Keywords

Reactions of 1-cyano-4-oxo-4H-quinolizine-3-diazonium tetrafluoroborate (1a) and 4-oxo-4Hpyridino[ 1,2-a]pyrimidine-3-diazonium tetrafluoroborate (1b) with aliphatic amines 2a - g were studied. Treatment of heteroaryldiazonium salts 1 with secondary amines 2a - d afforded the corresponding N-alkyl-N’-heteroaryltriazenes 3a - h in high yields. On the other hand, reactions of 1a with aliphatic primary amines 2e - g resulted in an unexpected rearrangements into the corresponding picolinic acid N-alkylcarboxamides 4a - c.
Magnetic Properties and Crystal Structure of a CuIIGdIII Heterodinuclear Schiff Base Complex
Authors: Elmali Ayhan , Elerman Yalçın
Published: August 2018

The crystal structure and the magnetic properties of a heterodinuclear complex, [LCu(Me2CO)Gd(NO3)3]2 (L=N,N’-bis(2-hydroxy-3-methoxybenzylidene)-1,3-diaminopropane) are reported: [(C19H20N2O4)Cu(C3H6O)Gd(NO3)3]2, triclinic, space group P1, with a = 12.118.3(9), b = 13.562(3), c = 9.391(3) Å , α = 93.03(3), β = 107.65(2), γ = 73.07(2)°, V = 1406.0(7) Å3, Z = 1. The crystal structure consists of two independent binuclear CuIIGdIII complexes and two non-coordinating acetone molecules in the asymmetric unit. The central region of the complexs is occupied by CuII and GdIII ions which are bridged by two phenolato oxygen atoms of the ligand. The CuII ion is in a square-planar geometry and coordinated by four donor atoms of the ligand (N2O2). The GdIII ion is deca-coordinated. In addition to the two phenolate oxygen atoms, its coordination sphere contains two oxygen atoms of the OMe side arms of L and six oxygen atoms from the three bidentate nitrate ions. The average Cu···Gd separation is 3.375(2) Å . The χT versus T plots, χ being the molar magnetic susceptibility per CuIIGdIII unit and T the temperature, has been measured in the 4 - 347 K range. The values of the intrachain interaction parameters have been deduced from the magnetic data: J = 7.4 cm−1, gCu = 2.12, gGd = 2.06. This indicates a weak ferromagnetic spin exchange interaction between CuII and GdIII ions. The nature of the magnetic super-exchange interaction of the title compound is compared with similar CuIIGdIII heterodinuclear complexes.