bluuebunny/crossref_metadata_2025 huggingface dataset:
Orthoamide, LXVII [1]. Bis(diformylamino)methan – ein neues leistungsfähiges Formylierungsmittel für aromatische Verbindungen / Orthoamides, LXVII [1]. Bis(diformylamino)methane – a New Efficient Formylating Reagent for Aromatic Compounds
Authors: Kantlehner Willi , Anders Ernst , Mezger Jochen , Stoyanov Edmont V. , Kreß Ralf , Wermann Kurt , Frey Wolfgang , Görls Helmar
Published: August 2018

Formaldehyde reacts with diformamide (10) to give N-(hydroxymethyl)diformamide (11), which upon treatment with thionylchloride yields N-(chlormethyl)diformamide (12) together with small amounts of oxydimethylenebis(diformamide) (13). Various diformylamine derivatives, such as diformylaminomethyl formiate (14), diformylaminomethylisothiocyanate (15) and the N-diformylaminomethylated guanidinium salt 16, can be prepared from 12. Bis(diformylamino) methane (7) can be obtained by the reaction of sodium diformamide (8) with either 1-(chloromethyl)pyridinium chloride (9) or N-(chloromethyl)diformamide (12) in acetonitrile. The action of tris(chloromethyl) amine (18) on sodium diformamide (8) affords tris(diformylaminomethyl)amine (19). The constitution of the compounds 7, 11 and 19 was confirmed by crystal structure determination. The nature of the products from the reactions of aromatic compounds with 12 depends on the Lewis acid which is used as activator. Thus the N-benzylformamides 20a, b can be obtained from toluene and mesitylene and 12/BF3-ether, whereas 1,2,4-trimethoxybenzene is formylated by 12/AlCl3 to give the aldehyde 22. Interestingly enough, a novel and efficient formylating reagent resulted from these investigations: bis(diformylamino)methane (7), which can be activated by Lewis acids, e. g. AlCl3. The scope of this procedure is comparable with that of the Olah-formylation method (formylfluoride/BF3).
Stereoselective Synthesis of Quinolizidine Alkaloids: (–)-Lasubin II
Authors: Weymann Markus , Kunz Horst
Published: August 2018

Based on a higly diastereoselective Mannich reaction of N-(3,4-dimethoxybenzylidene) 2,3,4,6- tetra-O-pivaloyl-β -D-galactopyranosylamine 3 with the Danishefsky diene the quinolizidine alkaloid lasubin II was synthesized in enantiomerically pure form in six steps.
A New Simple Method for the Preparation of Aryl Formates from Phenols
Authors: Hashmi Imran Ali , Kantlehner Willi , Ivanov Ivo C.
Published: August 2018

Aryl formates are prepared in a two step one-pot procedure from phenols. Firstly the formylating reagent triformamide (1b) is generated from sodium diformamide (2) and methanesulfonyl chloride in situ, which reacts with phenols 4a - f to give aryl formates 5a - f in good yields. Triformamide, prepared in situ, transforms anisole in the presence of aluminum chloride to the N-(diarylmethyl)formamide 7.
Syntheses and Crystal Structures of Sr7H12X2 (X = Cl, Br)
Authors: Reckeweg Olaf , Molstad Jay C. , Levy Scott , Hoch Constantin , DiSalvo Francis J.
Published: August 2018

Dichroic, pink to blue single crystals of Sr7H12Cl2 and Sr7H12Br2 were obtained by reacting Sr with SrX2 or NaX and NaNH2 or NH4X (X = Cl, Br) as hydrogen sources in a Na melt at 900 °C for 12 h in silica-jacketed stainless-steel or Ta ampoules. The crystal structures of the new compounds were determined by means of single crystal X-ray diffraction. Both title compounds crystallize isotypically to Ba7Cl2F12 in the hexagonal space group P6̅ (no. 174) with the lattice parameters a = 998.06(3), c = 392.84(3) pm for Sr7H12Cl2 and a = 1004.62(3), c = 399.68(3) pm for Sr7H12Br2. The hydride positions taken from the difference Fourier map agree with those of the fluorides of the isotypic compound Ba7F12Cl12. The validity of our structural results is corroborated by EUTAX calculations and the comparison to SrH2, SrX2 and SrHX.
Synthesis and Characterization of a New Copper(II) Complex with Nadolol, an Aminoalcoholic Beta-blocker. Crystal Structure of Na[Cu(nadololate)(CO3)] · H2O
Authors: Viera Inés , Domínguez Laura , Ellena Javier , Torre María H.
Published: August 2018

This work reports the synthesis and characterization of a new copper complex with nadolol, a betablocker aminoalcohol. The stoichiometry found was Na[Cu(nadololate)(CO3)] · H2O. Electronic and vibrational spectroscopy analysis was performed, and the crystal structure of Na[Cu(nadololate)-(CO3)] · H2O was determined by X-ray diffraction.
Synthesis and Antioxidant Properties of Some New 3-(4-Chlorophenyl)-5- (pyridin-4-yl)-4H-1,2,4-triazole Derivatives
Authors: Bekircan Olcay , Özen Tevfik , Gümrükcüoğlu Nurhan , Bektaş Hakan
Published: August 2018

A series of new 3-(4-chlorophenyl)-5-(pyridin-4-yl)-4-(arylmethyleneamino)-4H-1,2,4-triazole derivatives 3 were prepared in good yields by treatment of 4-amino-3-(4-chlorophenyl)-5-(pyridine- 4-yl)-4H-1,2,4-triazole (2) with selected aldehydes. Compounds 3 were reduced with NaBH4 to afford the corresponding 3-(4-chlorophenyl)-5-(pyridin-4-yl)-4-(arylmethylamino)-4H-1,2,4-triazole derivatives 4. Eighteen new compounds were synthesized and characterized by elemental analyses, IR, 1H NMR and 13C NMR spectral data. The compounds were screened for their antioxidant and antiradical activities.
Heterocycles [h]-Fused onto 4-Oxoquinoline-3-carboxylic Acid, V [1]. Synthesis and Antibacterial Activity of Some New 2,3-Disubstituted 7-Oxo-7,10-dihydropyrido[2,3-f]quinoxaline-8-carboxylic Acids and Esters
Authors: Abu-Sheaib Esra’a S. , Zahra Jalal A. , El-Abadelah Mustafa M. , Voelter Wolfgang
Published: August 2018

Cyclocondensation reaction of ethyl 7,8-diamino-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline- 3-carboxylate (2) or the -3-carboxylic acid 3 with sym-1,2- diketones produced the corresponding ethyl 2,3-disubstituted pyrido[2,3- f ]quinoxaline-8-carboxylates (4a - h) or the -8-carboxylic acids 5a - h, respectively. The structures for these new heterocycles are supported by analytical and spectral (IR, MS, NMR) data. Compounds 5a - c, g, h exhibit moderate activity against an assortment of bacterial species.
Heterocyclic Synthesis Using Nitrilimines: Part 9. Synthesis of New 1,3,4-Thiadiazin-5-one Derivatives
Authors: Dalloul Hany M. , Mohamed El-Hossain A. R. , El-Shorafa Ali Z.
Published: August 2018

A series of new 3,5,6-thiadiaza-4-hexenoates (4a - k) were synthesized from the reaction of the corresponding hydrazonoyl halides 1 with ethyl mercaptoacetate (3). These compounds underwent intramolecular cyclization to 1,3,4-thiadiazin-5-one derivatives (5a - k) in the presence of MeONa or LiH. The structures of the synthesized compounds were confirmed by their elemental analyses and spectral data.
Magnetism,Magnetotransport and Magnetic Structure of ThCu3Mn4O12, Prepared at Moderate Pressures
Authors: Sánchez-Benítez Javier , Martínez-Lope María J. , Alonso José A.
Published: August 2018

The complex perovskite ThCu3Mn4O12 has been prepared at moderate pressures of 2 GPa. With respect to the parent compound CaCu3Mn4O12, the replacement of Ca2+ by Th4+ involves a double electronic injection that leads to a substantial increment of TC, up to 370 K. The crystal structure was refined in the space group Im3̄ from NPD data collected with λ = 1.33 Å at r. t. An additional NPD pattern recorded at 1.8 K with λ = 2.42 Å allowed to refine the magnetic structure, which displays a ferrimagnetic coupling between Mn3+/Mn4+ and Cu2+ spins, aligned along the c direction. The refined magnetic moments at the Mn and Cu substructures of 2.5 and −0.5 μB, respectively, account for the observed saturation magnetisation at 2 K, of 7 μB/f. u. A semiconducting behaviour is observed between 10 and 350 K which can be correlated with the appearance of a gap in the conduction band for the ~50% Mn3+/50% Mn4+ mixed valence observed in the B substructure of this perovskite.
High-pressure Synthesis and Crystal Structure of the Vanadium Orthoborate VBO3
Authors: Haberer Almut , Huppertz Hubert
Published: August 2018

The vanadium orthoborate VBO3 was synthesized under high-pressure / high-temperature conditions of 7.5 GPa and 1250 °C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single crystal X-ray diffraction data, collected at r. t. The title compound crystallizes in the trigonal calcite structure, space group R3̄c, with the lattice parameters a = 462.0(1) and c = 1450.9(3) pm. Within the trigonal planar BO3 groups, the B-O distance is 138.8(3) pm. The vanadium atoms have a slightly distorted octahedral oxygen coordination (V-O: 202.3(2) pm).
Prion Protein Aggregation Induced by Copper(II) and Heparan Sulfate. Pressure-dependent Switch of Reaction Pathways
Authors: El Moustaine Driss , Torrent Joan , Lange Reinhard
Published: August 2018

Copper ions (Cu2+) and heparan sulfate (HS) are suspected to act as regulatory agents in the conversion of cellular prion protein (PrPC) to its infectious isoform. However, the mechanism of this reaction is still largely unknown. Our previous report suggested multidimensional pathways for structural alterations of PrP, which may be modulated by high pressure (HP). Here we use HP to investigate the effects of Cu2+ and HS binding on PrP conformational changes and assembly. In the presence of Cu2+, amyloid fibrils are formed only under HP. In contrast, in the presence of HS, fibrils are formed at atmospheric pressure, but not under HP. Both compounds appear to compete for the same binding site, since HS-supported fibril formation is quenched by Cu2+. Inversely, Cu2+- mediated fibril formation under HP is inhibited by HS.
Are Tetra[gold(I)]phosphonium Cations [(LAu)4P]+ Non-obedient to the LeBel-van’t Hoff Rule?
Authors: Schmidbaur Hubert
Published: August 2018

Recent theoretical studies of the molecular and electronic structure of tetra[(phosphine)gold(I)]- phosphonium cations, [(H3PAu)4P]+, gave contradictory results favoring either a classical tetrahedral or a unique square-pyramidal structure of the PAu4 unit. A tetrahedral structure had previously been confirmed for the corresponding ammonium cations [(Ph3PAu)4N]+, while a square-pyramidal structure was discovered for the corresponding arsonium cations [(Ph3PAu)4As]+, but there is as yet no unequivocal experimental evidence for the structure of phosphonium cations like [(Ph3PAu)4P]+ in an innocent environment. - In this account the structural chemistry of this class of onium salts and related species is reviewed. The data accumulated to date provide virtually compelling evidence that the phosphonium cations should have a ground state with a square pyramidal PAu4 core unit, provided that no external constraints are imposed. For large central elements (P, As), aurophilic interactions appear to drive the reorganization from tetrahedral to square-pyramidal skeletons in which a maximum number of short Au---Au contacts can be maintained. For the small central element N, similar interactions are already realized in the tetrahedral structure.
Spin-Spin Coupling Constants 1J(27Al,13C) and 1J(13C,11B) in Comparable Organoaluminum and -boron Compounds. NMR Spectroscopy of Lithium Tetra(tert-butyl)alanate
Authors: Wrackmeyer Bernd , Klimkina Elena V.
Published: August 2018

The 13C, 27Al and 11B NMR spectra of tri(tert-butyl)alane, AlBut
3, and of the corresponding borane, BBut
3, respectively, were examined in order to determine the magnitude of the coupling constants 1J(27Al,13C) = 94±5 Hz and 1J(13C,11B) = 52±2 Hz by measurement of the line widths of the 13C NMR signals and of the relaxation rates of the quadrupolar 27Al and 11B nuclei. This is the first example of 1J(27Al,13C) determined for a monomeric trialkylalane. In addition, the coupling constants were calculated by DFT methods (B3LYP) using the 6-311+G(d,p) basis set. The 1H, 13C and 27Al NMR spectra of lithium tetra(tert-butyl)alanate, Li[AlBut
4], were measured under various conditions. Ion-pair separation in THF revealed the expected patterns for 27Al-13C spin-spin coupling across one and two bonds as well as for the three-bond 27Al-1H spin-spin coupling.
Synthesis of 1,n-Acyloxy Thioamides by the Willgerodt-Kindler Reaction: Chemoselectivity of 1,3-Ketoesters over 1,3-Diketones
Authors: Darabi Hossein Reza , Aghapoor Kioumars , Balavar Yadollah , Mobedi Elham , Farhangian Hossein , Mohsenzadeh Farshid
Published: August 2018

Treatment of selected types of 1,3-ketoesters and their corresponding enamines by the Willgerodt- Kindler (WK) reaction afforded the corresponding 1,n-acyloxy thioamides. Based on the mechanistic study, the chemoselective thioamidation of 1,3-ketoesters occurs in the presence of 1,3-diketones.
Reactions of Substituted Carbohydrazides with Electron-poor Olefins
Authors: Hassan Alaa A. , Ibrahim Yusria R. , Shawky Ahmed M.
Published: August 2018

Substituted carbohydrazides 1a - e reacted with ethenetetracarbonitrile (2) in dimethylformamide with formation of diacylhydrazines 4a - e and 5-amino-1-substiuted pyrazole-3,3,4-tricarbonitriles 5a - e. On the other hand, 1a-c reacted with diethyl (E)-2,3-dicyanobutenedioate (3) to give oxadiazinone and pyrazolone derivatives 12a - e and 13a - e, respectively.
C–H···O-Brückenbindungen in Imidazolium-Carboxylaten / C–H···O Hydrogen Bonds in Imidazolium Carboxylates
Authors: Abu-Rayyan Ahmed , Abu-Salem Qutaiba , Kuhn Norbert , Maichle-Mößmer Cäcilia , Mallah Eyad , Steimann Manfred
Published: August 2018

2,3-Dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (1) reacts with benzoic acid to give the corresponding 1,3-diisopropyl-4,5-dimethylimidazolium benzoate salt 2. Similarly, 1,3-diisopropyl-4,5-dimethylimidazolium formiate (3) is obtained from 1 and ammonium formiate. In crystals of 2, the anions are linked to the imidazolium ions by monofunctional O···H-C bonds while in 3 bifurcated O・・・H-C bonds are observed. In 1,3-diisopropyl-4,5-dimethylimidazolium hydrogenoxalate (4), obtained from 1 and oxalic acid, hydrogen bonds connect both imidazolium ions to the hydrogenoxalate ions in a bifurcated mode as well as the anions to each other.
A 57Fe Mössbauer Spectroscopy Study of the 7 K Superconductor LaFePO
Authors: Tegel Marcus , Schellenberg Inga , Pöttgen Rainer , Johrendt Dirk
Published: August 2018

A polycrystalline sample of superconducting LaFePO was prepared in a tin flux at 1123 K. The structure was determined from single-crystal data (ZrCuSiAs type, P4/nmm, a = 3.9610(1), c = 8.5158(2) Å , Z = 2), and the phase analysis was performed by the Rietveld method. LaFePO is Pauli-paramagnetic and becomes superconducting at 7 K after removing the ferromagnetic impurity phase Fe2P from the sample. 57Fe Mössbauer spectroscopy measurements at 298, 77, 4.2, and 4 K show single signals at isomer shifts around 0.35 mm s−1, subject to weak quadrupole splitting. At 4 K, a symmetric line broadening appears, resulting from a small transferred magnetic hyperfine field of 1.15(1) T and accompanied by an angle of 54.7(5)◦ between Bhf and Vzz, the main component of the electric field gradient tensor.
Structural and Electronic Properties of Zinc Blende-type Nitrides BxAl1–xN
Authors: Riane Rabah , Boussahla Zouaoui , Matar Samir F. , Zaoui Ali
Published: August 2018

First principles total energy calculations were carried out to investigate structural and electronic properties of zinc blende-type AlN, BN and BxAl1−xN solid solutions. We have calculated the lattice parameters, bulk modulus, pressure derivative, and BxAl1−xN band-gap energy for zinc blende-type crystals of the compositions x = 0, 0.25, 0.5, 0.75, 1. The results show that the direct energy gap Γ15
V →Γ1
c shows a strong nonlinear dependence on the concentration x. For high boron contents

(x > 0.71), these materials have a phase transition from direct-gap semiconductors to indirect-gap semiconductors (Γ15
V → X1
c). This essential feature indicates that these materials should have very good optical properties at high concentrations of boron compared to those of AlN. Further discussions concern a comparison of our results with results obtained with other available theoretical and experimental methods.
Structure Chemical Aspects of Silver(I) Chalcogenide Halides and Preparation of the x = 1 Member of the Solid Solution Ag5Te2Cl1–xBrx
Authors: Messel Julia , Nilges Tom
Published: August 2018

The maximum grade of substitution to be reached in solid solutions Ag5Te2Cl1−xBrx by solid state melting reactions starting from the elements, is x = 0.65. Using solvothermal synthesis in aqueous ammonia solution, the area of stability can be extended to pure bromide (x = 1). X-Ray diffraction experiments have substantiated the isostructural features of Ag5Te2Br compared with the chlorine analog. At r. t. Ag5Te2Br crystallizes monoclinically, in the β -Ag5Te2Cl structure type, with lattice parameters of a = 14.000(5), b = 7.702(3), c = 13.856(6) Å , β = 90.61(4)°, space group P21/n. A topological approach, first introduced for the characterization of complex structures of silver(I) (poly)chalcogenide halides, has been transferred to the Ag5Q2X system. Based on this formalism the anion substructures can be described by simple nets or strands created by the connection of positions at distances close to or even larger than the sum of the van der Waals radii. In case of the present system, only honeycomb-like telluride nets and halide strands are necessary to explain the complex anion substructure. A deeper understanding of the physical properties, like the anisotropic silver mobility, can be achieved by this topological approach which was not possible with other structure description models.
Electrochemical Properties of Ag5Te2Cl0.8Br0.2, a Representative of the Solid Solutions Ag5Te2Cl1–xBrx
Authors: Bawohl Melanie , Nilges Tom
Published: August 2018

Impedance spectroscopic investigations of Ag5Te2Cl0.8Br0.2, a selected representative of the solid solutions Ag5Te2Cl1−xBrx with x = 0 - 1, proved the mixed-conducting property of this class of materials. Two polymorphs are realized in the temperature range of 309 to 410 K, the monoclinic β - phase (space group P21/n) and the tetragonal α-phase (space group I4/mcm) with an order-disorder phase transition temperature of 336 K (DSC). A sharp increase of the total and ionic conductivity can be observed at 337 K, in good accordance with the phase transition temperature. The electronic conductivity exceeds the ionic conductivity by approximately one order of magnitude over a wide range of temperature. Conductivities are σion = 6.9×10−5 (309 K) and σtot = 4.80×10−4 Ω−1 cm−1 (310 K) for β -Ag5Te2Cl0.8Br0.2 and σion = 1.6×10−2 (395 K) and σtot = 1.73×10−1 Ω−1 cm−1 (394 K) for α-Ag5Te2Cl0.8Br0.2.
A New Cyathane-xyloside from the Mycelia of Hericium erinaceum
Authors: Ma Bing-Ji , Zhou Yan , Li Lian-Zhen , Li He-Min , Gao Zhi-Ming , Ruan Yuan
Published: August 2018

A new cyathane-xyloside derivative, named erinacine R, was isolated from the mycelia of basidiomycete Hericium erinaceum. The structure of this compound was elucidated by spectral methods including 2D NMR experiments.
The Influence of the Amine Concentration onto Product Formation: Crystal Structures, Thermal Stability and Spectroscopic Properties of Two New Manganese Thiostannates Obtained under Solvothermal Conditions
Authors: Pienack Nicole , Näther Christian , Bensch Wolfgang
Published: August 2018

Two new thiostannates with Mn2+ ions were obtained under solvothermal conditions applying different amine concentrations. [Mn(C6H14N2)2(H2O)]2Sn2S6 (1) (C6H14N2 = 1,2-diaminocyclohexane, 1,2-dach) crystallizes in the monoclinic space group C2/c (with a = 23.7500(18), b = 15.5655(16), c = 12.1072(9) Å , β = 113.532(8)°, Z = 8). The second compound, [Mn(C6H14N2)2]- Sn2S6 ・2 C6H15N2 (2), crystallizes in the triclinic space group P¯1 with a = 7.3019(6), b = 11.1798(9), c = 13.2837(11) Å , α = 76.877(10), β = 74.719(9), γ = 82.972(10)°, Z = 1. Both structures feature [Sn2S6]4− anions acting as bidentate ligands and joining the octahedrally coordinated Mn2+ cations, but in 1 a molecular complex is formed, whereas in 2 a one-dimensional coordination polymer is observed. In 1 the Mn2+ cation has bonds to four N atoms of two 1,2-dach ligands, to one H2O molecule, and to one S atom of the [Sn2S6]4− anion. The [Sn2S6]4− anion is located on a center of inversion joining two symmetry related complexes. In 2 Mn2+ is surrounded by four N atoms of two 1,2-dach ligands and by two S atoms of two neighboring [Sn2S6]4− anions. In contrast to 1 a negatively charged coordination polymer is formed with [Sn2S6]4− anions acting as linkers and the Mn2+ centered complexes being the nodes. The co-crystallized 1,2-dach molecules are protonated, and they are located between the chains. The first compound was obtained from diluted aqueous solutions of 1,2-dach, and 2 crystallized from solutions containing < 25% H2O. In both compounds several short S···H distances indicate weak hydrogen bonding interactions. Compound 1 is stable up to 121 °C and 2 up to 220 °C. In the Raman spectra of 1 and 2 resonances which are typical for [Sn2S6]4− units could be observed. The band gaps are found to be 2.6 eV (477 nm) and 3.1 eV (400 nm) for 1 and 2, respectively.
Synthesis, Crystal Structure and Antitumor Study of an Iron(III) Complex of 2-Acetylpyrazine N(4)-Methylthiosemicarbazone
Authors: Zheng Lin Ping , Chen Chun Ling , Zhou Jing , Li Ming Xue , Wu Yan Juan
Published: August 2018

The title complex [Fe(C8H10N5S)2] · Cl has been synthesized from 2-acetylpyrazine N(4)-methylthiosemicarbazone and FeCl3 · 6H2O and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The complex consists of discrete monomeric molecules with octahedrally hexacoordinated iron(III) ions, in which two 2-acetylpyrazine 4-methylthiosemicarbazone units act as meridional NNS tridentate ligands coordinated to the central iron atom via the pyrazine nitrogen, azomethine nitrogen and sulfur atoms. Hydrogen bonds link the complex components to stabilize the crystal structure. The antitumor activity of the title complex was tested against K562 leucocythemia and BEL7402 liver cancer cell lines. The complex exhibits higher antitumor activity as compared to the free ligand.
1,2-Hydroboration of Alkyn-1-yldichlorosilanes using Triethylborane
Authors: Wrackmeyer Bernd , Khan Ezzat , Milius Wolfgang
Published: August 2018

Triethylborane, BEt3, can act as a 1,2-hydroborating reagent towards alkyn-1-ylsilanes, depending on the nature of the silane. A mechanism is proposed invoking hydrogen transfer from the β -carbon of one ethyl group, quite different from the 1,2-hydroboration mechanism using tri-n-propylborane, BnPr3. The structure of the products has been confirmed by comparison with that obtained using 9-borabicyclo[3.3.1]nonane, 9-BBN, as a well established 1,2-hydroborating reagent. All products have been characterized by a consistent set of NMR data (1H, 11B, 13C and 29Si NMR). The molecular structure of (Z)-1-dichlorosilyl-1-[9-(9-borabicyclo[3.3.1]nonyl)]-2-phenylethene has been determined by single crystal X-ray diffraction.
A Three-dimensional Manganese(II) 1,2,4-Benzenetricarboxylate Hydroxide Framework with Mn–O Inorganic Sheets: Hydrothermal Synthesis and Crystal Structure
Authors: Zhou Shuxi , Ke Yanxiong , Zou Hongliang , Liu Tianhua , Zhu Fang , Chen Jianmei , Xie Aijun
Published: August 2018

Utilizing unsymmetrical 1,2,4-benzenetricarboxylate (1,2,4-BTC) as a ligand, a complex [Mn2.5(1,2,4-BTC)- (OH)2(H2O)] was synthesized by hydrothermal reaction and characterized by single crystal X-ray diffraction. The coordination polymer crystallizes in the triclinic space group P1̅, with cell parameters a = 5.7702(5), b = 8.0269(6), c = 12.1378(9) Å, α = 88.000(1)°, β = 81.493(1)◦, γ = 88.569(1)°, and Z = 2. In the the crystal, there are Mn- O-Mn sheets which are further connected through the 1,2,4-BTC ligands into a 3D framework, which is rare in the coordination chemistry originating from transition metal ions and unsymmetrical polycarboxylates.
The Acetylacetonate Ion as its E/Z-Isomer in 1,3-Diisopropyl-4,5- dimethylimidazolium Acetylacetonate
Authors: Abu-Rayyan Ahmed , Abu-Salem Qutaiba , Mallah Eyad , Maichle-Mößmer Cäcilia , Steimann Manfred , Kuhn Norbert , Zeller Klaus-Peter
Published: August 2018

1,3-Diisopropyl-4,5-dimethylimidazolium acetylacetonate (2) is obtained from 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol- 2-ylidene (1) and acetylacetone. Its crystal structure reveals the presence of ion pairs linked by C-H ··· O hydrogen bonds. In 2, the acetylacetonate ion adopts the structure of its E/Z-isomer (C).
Photochemisch induzierte C–C-Verknüpfungen zwischen einem Mangan-koordinierten Pentadienylliganden und Acetylen
Authors: Koch Ernst-Christian , Reiss Guido J.
Published: August 2018

Irradiation of tricarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)manganese (1) in tetrahydrofuran (THF) at 208 K affords the carmine solvent complex dicarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)(THF)manganese (2). Complex 2 thermally reacts with acetylene (3) to give tricarbonyl(η3:2-1,3-dimethyl-bicyclo[3.3.1]-3,6-nonadien-2-yl)manganese (4) and dicarbonyl(5-7,10-13-η-6,8-dimethyl-1,3,5,8,10,12-tridecahexaen-5-yl)manganese (5). The crystal structure of complex 4 was determined at room temperature [triclinic space group

P

1
¯

,

$P\bar 1,$

a
=7.6891(9), b
=8.3860(8), c
=10.5252(13) Å, α
=93.000(9)°, β
=93.390(10)°, γ
= 108.032(8)°, V
=642.43(13) Å3]. The manganese atom is trigonal-bipyramidally coordinated by three carbonyl ligands, one ethenylic and one allylic fragment. Consequently, the bicyclic olefin ligand 1,3-dimethyl-bicyclo[3.3.1]-3,6-nonadiene coordinates the manganese atom in a η3:2 mode. The constitution of complex 5 was deduced from IR data, elemental analysis, and 1H NMR spectra. For the formation of complexes 4 and 5, a reaction mechanism is proposed.
Synthesis, characterization, and antitumor activity of some novel S-functionalized benzo[d]thiazole-2-thiol derivatives; regioselective coupling to the –SH group
Authors: Ramadan El Sayed , Abdel Hamid Hamida M. , Noureddin Sawsan A. , Badahdah Khadija O.
Published: August 2018

Several 2-substituted sulfanyl benzo[d]thiazoles were regioselectively synthesized by the reaction of benzo[d]thiazole-2-thiol (1a) with a variety of reagents under different basic conditions. Some 2-(2,3-disubstituted propyl sulfanyl)benzo[d]thiazoles were obtained from 2-(allylthio)benzo[d]thiazole, which was prepared by the allylation of 1a with allyl bromide in the presence of sodium hydride in dry N,N-dimethylformamide. Reaction of 1a with various pyrazolyl-quinoxaline derivatives was also investigated. Better yields and shorter reaction time were achieved for the synthesis of some derivatives by using ultrasound irradiation. The structural elucidation of all compounds was based on both analytical and spectroscopic data. The newly synthesized compounds were tested in vitro for their antitumor activity against Ehrlich ascites carcinoma (EAC) cells grown in albino mice. Doxorubicin was used as a standard antitumor antibiotic, and some compounds showed half maximal inhibitory concentration (IC50) in the range 40–68 μg mL−1.
The Correlation of Lipid Release and Photochemical Activities in Isolated Spinach Chloroplasts
Authors: Heise Klaus-Peter , Jacobi Günter
Published: August 2018

Purified isolated spinach chloroplasts were suspended in media of different pH and the extracts obtained after centrifugation were analyzed for their lipid composition. The quantity of lipids present in the supernatant increased considerably by lowering the proton concentration. Under alkaline conditions more than 30% of the phospho- and sulfolipids were released from the thylakoid membranes. A stabilization was achieved when higher concentrations of MgCl2 were present. Photochemical activities showed an uncoupling of photophosphorylation at pH 8.5 and 8.9, and a stabilization at pH 5.5. The correlation between phosphorylation and the release of lipids was further demonstrated in the presence of MgCl2 when the ATP-formation was protected under alkaline conditions. From the comparison of the lipid composition in the extracts obtained from broken chloroplasts and from fragments after sonication, the conclusion can be drawn that part of the phospho- and sulfolipids and monogalactolipids are located at the surface of the membrane. The majority of lipids released are bound to particles as demonstrated by the sedimentation in the ultracentrifuge.
Monolayer States of a Cyanine Dye Studied by a Spectroscopic Technique
Authors: Fromherz Peter
Published: August 2018

A single beam, single reflectance photometer for investigation of monolayers at the air water interface is described. A cyanine dye monolayer is studied. The molecular arrangements in different monolayer states are derived from the observation o f the monomer-dimer equilibrium of the dye chromophores.
ATP-Spaltung an der Zelloberfläche der Leukozyten aus normalen und leukämischen Ratten / ATP-Cleavage on the Cell of Leucocytes of Normal and Leukaemic Rats
Authors: Friedrich-Freksa H. , Simon A. , Pachowsky H.
Published: August 2018

ATP-cleavage on the surface of L-5222 leukaemic cells of the BD IX-rat occurs at a rate of only 20% of the corresponding value for normal leucocytes.
Bakterienwand und Tumorinduktion durch Agrobacterium tumefaciens / Bacterial Cell Wall and Tumor Induction by Agrobacterium tumefaciens
Authors: Beiderbeck Rolf
Published: August 2018

Bacterial cell walls are concerned with the tumor induction by Agrobacterium tumefaciens on leaves of Kalanchoe in two different ways: 1. If an inoculum of the virulent strain B6 of A. tumefaciens is mixed with cells of the avirulent strain IIBNV6 or with high concentrations of cell wall preparations from B6 itself tumor induction is inhibited. The same is true with cell wall preparations which were treated with ether or chloroform. In vitro growth of the bacteria is not influenced by cell wall preparations. 2. Penicillin inhibits tumor induction by inhibiting bacterial growth. Addition of penicillin as late as 8 hours after infection is still inhibiting tumor initiation. Growth of induced tumors is not inihited by penicillin.

The meaning of the two cell wall related processes in tumor induction is discussed.
Preparation of (1R )[1—2H]- and (1S)[1—2H]-Alcohols by Exchange Reactions Catalyzed by Yeast or a Coupled Enzyme System
Authors: Günther Helmut , Alizade Miguel A. , Kellner Max , Biller Florian , Simon Helmut
Published: August 2018

All possible enantiomers of stereospecifically labelled [1-2H] ethanol, propanol and butanol have been prepared on a scale of up to 7 ml. The R forms have been obtained by incubation of the alcohols with alcohol dehydrogenase and diaphorase (NAD: Lipoamide oxidoreductase, EC 1.6.4.3) in presence of catalytic amounts of NAD+/NADH in deuterium oxide. The S forms have been prepared with the same enzymes in ordinary water, from the corresponding [1,1-2H] alcohols. (IS) [1-2H] ethanol was prepared from [1,1-2H] ethanol and ordinary water, by a yeast catalyzed exchange reaction.
Die organspezifische Photodetermination der Entwicklung von Peroxydaseaktivität im Senfkeimling ( Sinapis alba L.) durch Phytochrom
Authors: Schopfer Peter , Plachy Claudia
Published: August 2018

The development of extractable peroxidase activity in the mustard seedling is controlled by phytochrome (Pfr; operationally: Continuous far-red light) in an organ specific manner (enhancement in the cotyledons and taproot, inhibition in the hypocotyl; Tables I, II). Detailed kinetics of peroxidase accumulation in the cotyledons (Figs. 2, 3) reveal the existance of a two-step induction mechanism: 1. Formation of a stable transmitter during a period of competence to Pfr (“determination phase“), and 2. development of peroxidase activity mediated by the transmitter during a later period of competence to the transmitter (“realization phase“). These two periods of seedling development are completely separated in time.
Interaction of ʟ-Tryptophan with Inosine and Guanosine
Authors: Ibán̅ez I , Pieber M. , Tohá J.
Published: August 2018

The equilibrium constants for the complex between ʟ-tryptophan and inosine are established by solubility measurements at different temperatures, the order of magnitude of these constants being about 103 times bigger than the corresponding one for the formation of guanosine-tryptophan or any other of the nucleoside-tryptophan complexes. The mode of association of these molecules is governed mainly by stacking interactions as it has been suggested from previous PMR results. The differences in magnitude obtained for the equilibrium constants of (I + T) with respect to (G + T) are discussed in terms of differences in solute-solvent and solvent-solvent interactions. Thermodynamic parameters inferred from the equilibrium constants at different temperatures support this suggestion. Infrared results on I-T complex suggest that changes at the ribose moiety occurs and that possible hydrogen bridges are involved in the mechanism of association besides the stacking interactions.
Wirkung von Lithium- und Rhodanidionen auf den Nukleinsäure-Stoffwechsel von Tetrahymena pyriformis, normalen und neoplastischen Säugerzellen / Effect of Lithium and Thiocyanate Ions on the Metabolism of Nucleic Acids of Tetrahymena pyriformis, Normal and Neoplastic Mammalian Cells
Authors: Wayss Klaus , Volm Manfred
Published: August 2018

An antagonistic influence of lithium and thiocyanate ions on the metabolism of nucleic acids has been demonstrated in Tetrahymena pyriformis. This effect corresponds to morphogenetic observations on other ciliates. Similar investigations on mammalian cells (L-cells, CV I-cells, Chang-livercells, HeLa-cells, and ascites tumor cells of Walker-carcinosarcoma 256, Yoshida-sarcoma, Zajdelahepatoma) showed, in contrast to the results in Tetrahymena, no antagonistic influence of lithium and thiocyanate ions: Both ions inhibit the DNA-synthesis, in tumor cells as well as in normal cells.
Massenspektroskopische Untersuchungen an Glycosylglyceriden / Mass Spectrometric Investigation of Glycosyl Glycerides
Authors: Budzikiewicz H. , Rullkötter J. , Heinz E.
Published: August 2018

The mass spectrometric fragmentation behavior of glycosyl glycerides is discussed with special regard to the localisation of the fatty acids present in the molecule and to the applicability for mixture analyses.
Ein Zusammenhang zwischen Anregungszuständen von Molekülen und biologischer Wirkung, wie Strahlensensibilisierung und Kanzerogenität / A Correlation between the Properties of Excited States of Molecules and Biological Activity, as Radiosensibilization and Carcinogenic Activity
Authors: Popp Fritz A.
Published: August 2018

From the differences in electronic structure of 5-halogenated uracil derivatives and thymine there is discussed the connection with different radiosensibilization. At the same time the calculated energy change of the second and third excited singlet states for the particularly sensibilizating substances 5-bromo-uracil and 5-iodo-uracil compared with the remaining uracil derivatives is remarkable. In connection with different charge distribution this difference in principle may cause different energy transport processes. The very phenomenon is to be mentioned which has been discussed in previous papers dealing with the different carcinogenic molecules 3,4-benzpyrene and 1,2-benzpyrene.
Variable Content of a (GC) Rich Satellite DNA in Tumorous and Normal Cultures of Crepis capillaris
Authors: Sacristán Maria Dolores , Dobrigkeit Ingeborg
Published: August 2018

Analyses of DNA from tumorous and non tumorous cultures of Crepis capillaris by analytical equilibrium centrifugation in a neutral CsCl gradient revealed significant differences in regard to the content of a heavy component satellite, which was more highly represented in tumorous cultures. DNA of plant leaves showed a unimodal distribution of molecules. The choice of suitable controls served to demonstrate that the component satellite was not exclusive of tumorous tissues. The higher satellite content of tumorous cultures is probable related to their higher growth rate.
Landing Reaction of Musca domestica, IV: A. Monocular and Binocular Vision; B. Relationships between Landing and Optomotor Reactions
Authors: Taddei-Ferretti Cloe , de Talens Antonio Fernandez Perez
Published: August 2018

1. The behaviours of monocular and binocular flies are compared with respect to the landing reaction. It is found that landing reaction is elicited through different mechanisms by stimulating the zones of single or of double vision: Monocular stimulation in the field of single vision evokes reactions with both ipsilateral and contralateral leg s; monocular stimulation in the field of double vision evokes reaction only with the ipsilateral legs. 2. T he relationships between landing and optomotor reactions are analyzed. It is found that, a. W hen the fly is not free to turn itself, it may react to a lateral displacement in the visual field (optomotor stimulus) with a landing reaction ; b. The threshold for landing evoked by an expansion in the visual field (landing stimulus) is much low er than the threshold for landing evoked by a lateral displacement; c. A horizontal lateral displacement in the visual field of an eye is adequate to evoke the landing reaction only if it is perceived in the direction from the front to the back of the eye; d. W hen the fly is free to turn itself, it can present both landing and opto­motor reactions to a optomotor stimulus; e. W hen the fly is fixed at a point, landing reaction can be evoked also by an escape stimulus.
Lateral Inhibition in the Com pound Eye of the Fly, Musca
Authors: Kirschfeld K. , Lutz B.
Published: August 2018

Lateral Inhibition, Compound Eye, Fly Lateral inhibition is a common phenomenon in the eyes of vertebrates as well as of invertebrates. Indications of lateral inhibitory interactions in dipteran eyes have been found by means of electro-physiological techniques*' 2. It was not possible,
Gravitational Stimulations Inhibit Oscillatory Growth Movements of Plants
Authors: Johnsson Anders
Published: August 2018

Spontaneous oscillatory growth movements around (or across) the plumb line occur in young sunflower seedlings. The period is about 2.5 h. When such plants are tilted 90° and continuously rotated around their axis with a speed of 0.5 rpm, the oscillatory spontaneous movements cease. The findings are interpreted as supporting a previously published model for gravitationally induced plant movements.
A Comparison of the Methods of Molt Staging According to Drach and to Adelung in the Common Shore Crab, Carcinus maenas
Authors: Spindler Klaus-Dieter , Adelung Dieter , Tchernigovtzeff Catherine
Published: August 2018

Molt stages of juvenile Carcinus maenas were determined independently according to the methods of Drach and of Adelung. With the exception of stage DO the two systems agree rather well over the whole intermolt cycle. The molting hormone contents of animals regenerating several lim bs and whose molt stages were determined according to Drach are in the same range as the values published by Adelung.
Notizen: Sex Pheromone of Lobesia botrana : (E,Z)-7,9-Dodecadienyl Acetate in the Female Grape Vine Moth
Authors: Buser Hans-Rudolf , Rauscher Stefan , Arn Heinrich
Published: August 2018

Mass spectrometry in combination with high resolution gas chromatography were used to demonstrate the presence of (E,Z) -7,9-dodecadienyl acetate in Lobesia botrana females. The data indicate that this male attractant is a natural sex pheromone of the grapevine moth.
Notizen: Spezifische Verbindungsstrukturen der Faserzellen von Trichoplax adhaerens F. E. Schulze/Special Connecting Structures between Fiber Cells of Trichoplax adhaerens F. E. Schulze
Authors: Schulze F , Schulze F , Grell Karl , Benwitz Gertrud
Published: August 2018

In the primitive metazoan, Trichoplax adhaerens, the fiber cells are responsible for the change of shape. Electron microscopy reveals connections between protoplasmic strands of neighbouring cells marked by an osmiophilic disc-like structure. Possible functions are discussed.
Small-Angle X-Ray Scattering Studies of 1/10-Size and 1/20-Size Molecules of Helix pomatia α-Hemocyanin
Authors: Pilz Ingrid , Walder Karin , Siezen Roland
Published: August 2018

The small-angle X-ray scattering of 1/10-size molecules (in 0.1 ionic strength Tris buffer pH 8.1) and 1/20-size molecules (in 0.1 ionic strength ethanolamine buffer pH 10.6) of α-hemocyanin of the snail Helix pomatia was studied.

The radii of gyration, 8.7 nm and 8.0 nm for 1/10-size and 1/20-size molecules respectively, and the shape of the scattering curves indicate that both have a very anisotropic shape. Comparison of the experimental scattering curve of 1/10-size molecules with theoretical scattering curves gives the best agreement for flat cylinders or quadratic prisms the diameter respectively side of which is about 10 times larger than the height (dimensions side = 21 nm, height 2 nm). The scattering curves of various models composed of larger and smaller subunits were calculated; the best agree­ment was found also for flat models of similar dimensions.
Die Synthese von Lipochinonen und isoprenoiden Pigmenten bei der Ergrünung von Etioplasten im Blaulicht / Synthesis of Lipoquinones and Isoprenoid Pigments during Greening of Etioplasts in Blue Light
Authors: Kleudgen Hans , Lichtenthaler Hartmut
Published: August 2018

Blue light induces in etioplasts of Hordeum seedlings parallel to the formation of chlorophyll an increased synthesis of carotenoids, plastidic benzoquinones and vitamin K1.

1. Blue light induces an enhanced synthesis of β-carotene, lutein, violaxanthin, and neoxanthin, while the levels of antheraxanthin and zeaxanthin are decreased.

2. In contrast to the etiolated tissue a much higher portion of total plastoquinone-9 (oxidized and reduced form) is formed in blue light than total α-tocopherol (+ α-tocoquinone), and a higher portion of the oxidized quinone forms plastoquinone-9 and α-tocoquinone.

3. The blue-light-induced changes of the isoprenoid lipid synthesis described here are similar to those obtained in continuous far-red light. It is, therefore, suggested that blue light is effective via the blue absorption bands of the phytochrome system.

4. Blue-light-induced greening of etioplasts results in a much higher synthesis rate of chlorophyll a and other isoprenoid thylakoid lipids as compared to red light. This enhancement of thylakoid lipid formation appears to be a special blue light effect.
Zur Bedeutung der "richtigen" Syntax auditiver Muster für deren vokale Beantwortung durch Amseln / On the Relevance of the "Right" Syntax of Auditory Patterns to Vocal Responses of Blackbirds
Authors: Todt Dietmar
Published: August 2018

Male blackbirds (Turdus merula) were confronted with recordings of normal and experimentally modified song-phrases of their own repertoire. I tested the characteristics of the equivalent vocal responses (= stimulus A → vocalization A) of the birds. As I found the "right" (= the indivi­dually known) syntax (= sequential order) of the elements (= notes) of the phrases were an essential condition for these responses. The different elements (notes) of a phrase took part in the facilitation of the vocal responses particularly (Fig. 1A) . - Phrases modified in their syntax proved to be ineffective in the above mentioned sence; even if the modification remained inside the conspecific range of individual differences between blackbirds. The onset of the ineffectiveness started at that point of the stimuli at which the syntactic modification began (Fig. 1 B, C). However, after an experimental period of 20 days most of the modified phrases (presented to the birds about 100 times per day) began to become effective, that means: to facilitate equivalent vocal responses (Fig. 2). - I concluded that the birds possess a "syntactic filter" which interacts with the genera­ tion of specific vocal reactions on the auditory stimuli. The results show that this filter can be modified.
Control of Phenylalanine Ammonia-lyase and Ascorbate Oxidase in the Mustard Seedling by Light and Hoagland's Nutrient Solution
Authors: Peter K. , Mohr H.
Published: August 2018

Phytochrome, Phenylalanine Ammonia-lyase, Ascorbate Oxidase, Hoagland's Solution, Mustard Seedling Hoagland's nutrient solution (HS) * was used as a tool to investigate whether or not the phyto­ chrome-mediated appearance of phenylalanine ammonia-lyase (PAL) * and ascorbate oxidase (AO) * in the mustard seedling cotyledons is simply a modulation of the appearance of these enzymes in the dark (basal level). HS was applied to the mustard (Sinapis alba L.) seedling at sowing instead of distilled water. It was observed that HS causes a stimulation of enzyme dis­ appearance (interpreted as degradation) in light and dark. This effect becomes obvious at approximately 48 h after sowing. On the other hand, however, HS exerts specific effects on the appearance of the enzymes in continuous far-red light (which is considered to operate exclusively via phytochrome). In the case of PAL there is a strong stimulation of the rate of enzyme appearance; however, the onset of activity increase remains precisely at 29 h after sowing irrespective of treatment. In the case of AO the onset of activity increase is shifted by approximately 6 h ; however, the rate of enzyme appearance remains the same (up to 54 h after sowing). The data suggest that HS specifically affects phytochrome-mediated enzyme syntheses whereas syntheses of the same enzymes in the dark are not affected. It is concluded that the appearance of PAL and AO in the dark and phytochrome-mediated appearance of these enzymes are independent phenomena. Some consequences of these conclusions for the interpretation of density labelling data obtained with "inducible" enzymes are discussed.
The Use of Spermidine for the Isolation of Nuclei from Mouse Liver. Studies of Purity and Yield During Different Physiological Conditions
Authors: Christensson Eric , Lewan Lillemor
Published: August 2018

A 15 min method for the isolation of clean liver cell nuclei from normal, starved, hepatectomized and sham operated mice in mediums not containing bivalent cations is described. The iso­lation medium contained 0.5 mм spermidine for stabilization of the nuclear membrane, and macaloid and EDTA for inhibition of RNase activity. The RNA/DNA ratio in normal liver cell nuclei was 0.25 - 0.29 and the protein/DNA ratio 5.2. The RNA/DNA ratio was 0.23-0.25 after starvation for 24 hours and increased to 0.5 at 72 and 144 hours after partial hepatectomy.
Bacterial Hydroxylation of Pyrazon Compounds
Authors: Frenne E. de , Eberspächer J. , Lingens F. , Schäfer W.
Published: August 2018

In cell suspensions of bacteria grown with 5-amino-4-chloro-2-phenyl-3 (2H)-pyridazinone (pyrazon) as sole source of carbon o-methyl-pvrazon and m-methyl-pyrazon were converted to the cor­ responding hydroxymethyl compounds. p-Methyl-pyrazon was not metabolized.
Anthraquinones of Certain Egyptian Asphodelus Species
Authors: Hammouda F.M. , Rizk A.M. , El-Nasr M.M. Seif , Asr El-N
Published: August 2018

The study of the anthraquinones of Asphodelus fistulosus and A. microcarpus resulted in the isolation of chrysophanol, aloe-emodin, anhydrorugulosin, three others bianthraquinones (the cleavage products of which are either 1 ,8 -dehydroxyanthraquinone or chrysophanol) and chrysophanol-8 -mono-β-ᴅ-glucoside. The obtained results revealed a qualitative difference in the anthraquinone content of the different parts (leaves, seeds and tubers).