bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Reaction of ᴅ-Amino Acid Oxidase with β-Chloroalanine
Authors: Miyake Yoshihiro , Abe Teruko , Yamano Toshio
Published: February 2015

The reactions of ᴅ-amino acid oxidase with β-chloro-ᴅ-alanine and β-chloro-ʟ-alanine have been described. Both the holoenzyme and the apoenzyme catalyse the deamination of β-chloro-ʟ-alanine to keto acid without any consumption of oxygen or oxidation-reduction of the enzyme-bound FAD. The anaerobic reaction of the holoenzyme with β-chloro-ᴅ-alanine involves three phases with respect to the reduction of the enzyme-bound FAD, the rapid formation of an intermediate spectral species followed by a steady state of this intermediate and the last decay of the intermediate to the fully reduced enzyme. The rate of keto acid formation decreases as the reaction proceeds and ceases at the beginning of the conversion of the intermediate to the fully reduced enzyme. The aerobic reaction of the holoenzyme with β-chloro-ᴅ-alanine is biphasic. The first rapid oxygen consumption is followed by the second slow oxygen consumption. The second slow phase disappears by treating the enzyme with glutathione before the addition of substrate.
Untersuchungen zur Konfiguration von 4-Nitroimidazolnucleosiden / Investigations on the Configuration of 4-Nitro Imidazole Nucleosides
Authors: Vergin Hartmut , Bauer Hermann , Kuhfittig Gisela , Voelter Wolfgang
Published: February 2015

It is demonstrated that the 220—225 nm Cotton effect of 4-nitro imidazole nucleosides can be used for the determination of the configuration of this class of compounds. A more detailed picture about conformation and configuration of the sugar residue is received from the copperammonia complexes of these nucleosides.

The pH-dependency of the stability and the complex ratio are discussed for a furanose moiety. Correlation between signs and intensities of the Cotton effects and configurations and conformations of the diol structures are discussed.
5. Mitt.: Über den Einfluß von Ethambutol auf den endogenen Stoffwechsel von M. smegmatis / The Endogenous Metabolism of Mycobacteria V: The Influence of Ethambutol on the Endogenous Metabolism of M. smegmatis
Authors: Reutgen H. , Iwainsky H.
Published: February 2015

1. Under conditions of the endogenous respiration the mode of action of ethambutol on mycobacteria was studied. Oxygen uptake, 32P-incorporation and changes in the phosphate-content were measured as parameters for the behaviour of the metabolism.

2. In order to localize the first step of inhibition the radioactive isotope was applicated in a fixed chronological order and a fractionation in acid-soluble fraction, polyphosphate-, RNA- and DNA-fraction was carried out.

3. Proportional to the incubation periode the 32P was incorporated into the acid-soluble fraction, into the polyphosphate- and into the RNA-fraction in about the same proportions. The content in the DNA-fraction is nearly 200-times lower than in the RNA-fraction.

4. The main part of the phosphate is localized in the RNA (∼60%). Only in the begin of the incubation periode the part of the acid-soluble fraction is higher than that of the polyphosphate fraction.

5. The main part of the phosphate, transferred from the culture medium into the bacteries, was found in the polyphosphate fraction. During the incubation periode the phosphate-content in the RNA-fraction remains nearly unchanged. After decreasing to the begin the same was found for the acid-soluble fraction.

6. The specific activity of the polyphosphate fraction rises not continuously, according to the changes of the polyphosphate-content. Depending on the incubation periode the occured changes in the relations of the single fractions are similar in both the control- and the Ethambutol-trial.

7. In contrary to the results of other authors these investigations showed the same degree of inhibition of the phosphate metabolism in the acidsoluble fraction, the polyphosphate and the RNA-fraction.

8. Under conditions of the endogenous respiration ethambutol is inhibiting the phosphorylation of specific compounds of the intermediar-metabolism in the acid-soluble fraction or their further reactions. On the other side the changed incorporation of the 32P can be explained with a alterated permeability of the cell wall of the bacteria.
Isoelectric Behaviour of Different Rabbit Interferons Induced by Newcastle Disease Virus
Authors: Hellmann Wolfgang , Kohlhage Heinz
Published: February 2015

The isoelectric behaviour of the NDV-induced rabbit serum interferon was compared with different NDV-induced interferons from rabbit cells. The activity of serum interferon was found in a pH range from 4.6—6.2. In contrast, the isoelectric positions of cell interferons could be demonstrated in a more acid pH range between pH 3.7 and 5.0.
Untersuchungen an biochemisch wirksamen ligandensystemen, VI
Authors: Fritz Heinz P. , Von Stetten Otto
Published: February 2015

The IR, Raman and 1H-NMR-spectra of Hadacidin (N-formyl-N-hydroxylglycine) and its mono alkali salts are reported and discussed in terms of a structure proposal. The acidity constants given in the literature are corrected
Morpholines, V
Authors: Abdulla Riaz F.
Published: February 2015

A new synthesis has been developed for the hitherto unreported 2-substituted-3-oxo-4H-1,4-oxazines 3b-3j via the cyclodehydrohalogenation of N-aryl-N-dichloroacetyl-2-amino-4′-nitroacetophenones in dimethyl sulfoxide with potassium t-butoxide. The structures of all the oxazine derivatives have been verified by IR and NMR spectroscopy and correlations between the structures and spectrographic characteristics have been made. In every case the only tautomer present was the one in which the carbonyl group in position 3 of the oxazine ring existed in the “keto” form. Attempts to extend these cyclic elimination reactions to the synthesis of oxazepines have failed
Die 1H-NMR-spektroskopische Untersuchung der Struktur der dimeren 1.3-Dimethyluracile1 / Structure Determination of Dimeric 1,3-Dimethyl-Uracils by 1H-NMR-Spectroscopy
Authors: Fahr Egon , Maul Peter , Lehner Karl-Adolf , Scheutzow Dieter
Published: February 2015

Structures of dimeric dimethyl-uracils have been established by simulation of 90 Mc NMR spectra
Kinetische und proteinchemische Untersuchungen am Succinyl-Papain / Kinetic and Chemical Investigations of Succinyl-Papain
Authors: Löffler H. G. , Schneider Fr.
Published: February 2015

Kinetic studies of the reaction of papain with succinic anhydride demonstrate the reactivity of 10 amino groups, two of which are easily deacylated giving a stable succinylpapain with 3 free amino groups one of which is the free amino group of the terminal isoleucin. This modified enzyme has the tenfold solubility of papain between pH 5,9 - 9 and is a little more sensible to temperature than papain. Kinetic parameters of succinylpapain with N-Benzoyl-ʟ-arginine ethylester are: Km app =1,2 x 10-2 ᴍ( papain: 1,8 x 10-2 M) κcat=505 min-1 (papain: 475 min-1) at pH 6,2 and 37°C. The activity with the anionic substrate casein was 120 ± 10%, with the cationic protamine was 200 ± 20% of the activity of papain.

Nitration of 17 ± 1 tyrosines of succinylpapain with tetranitromethane has only a limited effect on the activity of the enzyme. The kinetics of this reaction suggests the existence of three groups of tyrosines with different reactivity. The reaction of papain with tetranitromethane gives only insoluble, cross-linked products.

Three of five present tryptophanes of papain and succinylpapain are oxidized by N-bromosuccinimide in the native state; in 8 ᴍ urea all residues are accessible. The esterase- and proteolytic activity of the oxidized enzyme decrease to less than 50% of controls while with benzoyl-ᴅ, ʟ-arginine-p-nitro-anilide there was observed an increased activity of about 250%. The stability of the enzyme drops considerably after oxidation of five tryptophane residues. Function and reactivity of the modified amino acids are discussed with regard to the results of the x-ray analysis of the enzyme
The Effect of some Sodium Substitutes on the Receptor Potential of the Crayfish Photoreceptor Cell
Authors: Stieve H. , Gaube H. , Malinowska T.
Published: February 2015

Isolated crayfish retinas were perfused with four solutions in which Li+, ΝΗ4
+, Tris H+ and glucose were substituted for the sodium ions in the physiological salt solution.

The changes of the extracellularly recorded receptor potential (ReP) evoked by short or long stimuli were measured. The changes in the shape of ReP by test solutions were different for each Na-substitute.

For lithium ions as a Na-substitute (Tab. I and Fig. 3) the plateau value he was considerably decreased (to ∼20%) contrary to the peak-amplitude hmax which even slightly increased.

Ammonium ions show quite a different effect than all the other substitutes. The ReP is decreased strongly and irreversibly (Tab. II and Fig. 4).

When Tris (hydroxymethyl-ammoniummethane-hydrochloride) is substituted for Na, hmax decreased to about 60 per cent and the plateau is even more reduced (to 20 per cent; Tab. III). Only the recovery-value for he (50% smaller) is markedly different contrary to our former experiments where choline was used as Na-substitute (decrease 20%).

Glucose as a substitute for sodium chloride caused strongly decreased peak-amplitude hmax 26%

(Tab. IV and Fig. 9). Increased osmotic pressure due to excess glucose causes irreversible damage of the ReP (Tab. V). All the changes except those produced by NH4
+ were reasonably reversible.

The results can be explained by the following assumptions:

a) the maximum of the ReP is caused mainly by an increase in the permeability of the cell membrane for sodium. Ca- and Mg-ions also contribute to it to a certain degree.

b) The plateau value of the ReP to long light stimuli is determined:

1. by the sodium concentration gradient,

2. by active transport processes,

3. by the Ca++ - and Mg++-gradients,

4. the chloride gradient may perhaps contribute to this value
Krebszellkinetik und Krebs-Mehrschritt-Therapie / Cancer Cell Kinetics and Cancer Multistep Therapy
Authors: Von Ardenne Manfred
Published: February 2015

Basic to the proposed therapeutic usage of the difference in the in-vivo proliferation control between cancer and normal cells are the temporary selective increase in the proliferation rate and number of cancer cells in all kinds of tumors but without increase of the proliferative activity of normal cells. To further this aim, measurements of cellular kinetics are used, in connection with the glycolysis of different tumor tissues under saturation conditions, with the relationship between cancer cell cycle and glycolytic rate, or the local glucose level respectively, with the wide range of glucose concentrations in tumor regions which differ the conditions of supply, with the pO2-value critical for tumor growth (≈ 0.4 Torr), with the pO2-distribution in tumor tissues and the time distribution of cell cycles in human and animal cancerous tissues. From an approximative description of the cytostatic effects in different tumor regions and its validity limits it is estimated that the sensitivity towarts therapy is decreased to as low as one-tenth in poorly supplied tumor regions. These particular fractions of the tumor tissues determine the degree of tumor resistence. Additionally, from these considerations steps can be derived which could be important for multiplying the effect of the cytostatic attack on the critical tumor regions with poor supply conditions. These steps include: a) usage of combinations of cytostatic agents directed against all three sensitive phases of the cell cycle (S-G2-M); b) increase in blood glucose concentration to about 300 mg% for an optimum time span prior to the initiation of the main therapeutic process; c) increase in pO2 of the inspiration air to 320 or 400 Torr and in the degree of pO2 utilization by the use of specific pharmaceutic agents for the chosen time span preceding the main therapy; d) stimulation of tumor vascularization preceding the main therapy; e) decrease in the fraction of tumor cells utilizing glucose and O2 as a consequence of a post-therapy treatment 72 hours after the main therapy. The increase in the fraction of cells in a sensitive phase of the cell cycle is reached folowing synchronization after increasing the glucose concentration until saturation of the glycolytic capacity. Reasons are given, why the cytostatic attack has to be supplemented by other selective mechanisms which damage the tumor cell independent of the phase of the cell cycle. Such a mechanism is the lysosomal cytolytic chain reaction. Here, the death of tumor cells occurring during a sensitive phase of the cell cycle as a consequence of the cytostatic attack helps to damage cancer cells which are in the insensitive phase. A further mechanism of this kind is the immunological attack, which is also a component of multi-step cancer therapy
Die γ-Radiolyse und Pulsradiolyse des Schwefelkohlenstoffs in wäßriger Lösung / The γ-Radiolysis and Pulse Radiolysis of Carbon Disulfide in Aqueous Solution
Authors: Roebke W. , Schöneshöfer M. , Henglein A.
Published: February 2015

A polymer (CHS2)n and sulfate are formed in the γ-irradiation of deaerated aqueous carbon disulfide solutions. The G-values are 3.6 and 0.41, respectively. In the presence of N,O, G (polymer) is decreased while G(SO4
-) is increased. G(SO4
-) can be decreased by isopropanol. G(polymer) is increased by H+ ions and reaches a value of 5 below pH = 2. Formic acid, hydrogen sulfide and carbonate are formed in the hydrolysis of the polymer. Pyrolysis at first leads to a red oil consisting of oligomer (HCS2)n and finally to H2S, CS2 plus a residue containing much carbon. The structure of the polymer is discussed.

Pulse radiolytic experiments show that CS2 reacts with eaq (3.1 × 1010M-1s-1) and OH(7.4 × 109M-1s-1) in a diffusion controlled manner. The first product of the reaction with OH is SC(OH)S. The pK of the electrolytic dissociation

SC(OH)Ṣ ⇄ SC(O-)S + H+

is 4.4. The absorption spectra of SC(OH)S and SC(O-)S were measured. SC(OH)S disappears by second order with 2k = 1.6 × 109M-1s-1 at pH = 6. The product is a bivalent acid, the spectrum of which was measured. The second pK of this acid is 5.7, its first pK is lower than 4.

Both eāq and H react with CS2 to form SCS-. The absorption spectrum of this radical anion was measured. The pK of the equilibrium

SCSH ⇄SCS- + H+

is about 1.6. In solutions of low H+-concentration, SCS- disappears by second order with 2k = 6.4 × 109M-1s-1. The structure of dithioformic acid is attributed to the resulting product. In solutions of high H+-concentration, SCS- (or SCSH) disappears by a fast first order process, the rate constant of which increases with H+-concentration. The carbeniat neutralization

is believed to be responsible for this process. The rate constant is 5.1 × 107M-1S-1. The spectrum of SC(H)S was measured. This radical disappears by second order with 2k = 7.4 × 109M-1s-1. The spectrum of the resulting product was also determined.

It is concluded that the formation of the polymer and of SO4
- occurs in processes in which the first products from the attack of eāq, H and OH on CS2 as well as molecules which were built up from these products are involved.
Temperature Variation of Principal Moments of Some Polyatomic Crystals
Authors: Singhal O. P.
Published: February 2015

Principal moments of some of the polyatomic single crystals such as ammonium dichromate, ammonium chromate, potassium chromate and potassium permanganate have been determined from room temperature down to liquid air temperature. These have been found to decrease with the decrease of temperature. This variation is smaller in magnitude. It has been observed that the temperature coefficient of the principal moments has almost the same value over the entire range of temperature. This small variation of paramagnetism has been attributed to the variation of absorption frequency in solid state.
Über Metalltrifluorphosphin-Komplexe. XL. / On Metaltrifluorophosphine-Complexes, XL.
Authors: Kruck Thomas , Sylvester Gerd , Kunau Inge-Petra
Published: February 2015

Orange-red crystals of μ3-phosphido-nonakis(trifluorophosphine)-triiridium, PIr3(PF3)9, are obtained by reductive fluorophosphination of IrCl3 at 80-200 atm PF3-pressure. The structure of the new complex is proven by its mass spectrum, displaying a successive removal of nine PF3-groups. Rupture of the PIr3-cluster occurs only to an extremely small amount even with high energy electrons. UV-irradiation of HCo(PF3)4 and a mixture of HCo(PF3)4 with HIr(PF3)4 yields the bridged complexes (PF3)3Co(H)(PF2)Co(PF3)3 and (PF3)3Co(H)(PF2) Ir(PF3)3. The three complexes (PF3)4M-M(PF3)4 (M = Co or Ir) with a direct metal-metal bond are not obtainable under these conditions. The mass spectra of all compounds and of Ir2(PF3)8 are discussed.
Beiträge zur Chemie von Molybdän und Wolfram. XI / Contributions to the Chemistry of Molybdenum and Tungsten. XI.
Authors: Schröder F. A. , Scherle J.
Published: February 2015

The direct reaction of MoO3 and WO3 with ethylenglycol and glycerol is reported. The prepared compounds were characterized by chemical analysis, IR-spectra and X-ray diffraction methods (powder and single cystal). Some chemical properties are given. All results indicate that the new compounds are derivatives of the hitherto unknown ortho-molybdic (VI) and tungstic (VI)-acids.
Oscillatory Oxidation of Malonic Acid by Bromate
Authors: Bornmann L. , Busse H. , Hess B.
Published: February 2015

At room temperature the chemical reaction between malonic acid (0.2 M) and KBrO3 (0.06 м) in 1 м H2SO4 is catalysed by cerium ions. The oscillation of the yellow Ce4+ ions can be observed directly during the reaction. By silica-gel chromatography the brominated products of the reaction have been identified as dibromoacetic acid and bromomalonic acid.
Hydration, Schichtsolvatbildung und Kationenaustauschreaktionen nichtstöchiometrischer ternärer Sulfide des Titans / Hydration, Layer Solvate Formation and Cation Exchange of Nonstoichiometric Ternary Sulfides of Titanium
Authors: Schöllhorn Robert , Weiss Armin
Published: February 2015

Nonstoichiometric ternary phases (MI)x[TiS2] with MI = Li, Na, K were prepared by reaction of TiS2 in salt melts of the corresponding alkali halides under H2S/CS2 atmosphere. The compounds form hexagonal crystal plates with negatively charged [TiS2]x--layers of the CdJ2-type and alkali cations located between the metal sulfide sheets. They react with water to form hydrates, whose layer distances depend on the radius of the alkali cation and on the ambient water vapour pressure. A variety of layer solvate complexes is obtained by partial or total replacement of the water with polar molecules, which are able to solvate the metal sulfide layers and the interlayer cations. The latter may be exchanged with mono- and divalent inorganic and organic cations.

Similar reactions were observed with a number of ternary layer chalcogenides (MI)x⁻ [(MII)yXz] with MI = Li, Na. K, Rb, Cs; MII = Zr, Hf, V. Nb, Ta, Cr, Ni, Pd, Pt and X = S, Se.
Photoelectron Spectra and Molecular Properties. XVII
Authors: Stafast H. , Bock H.
Published: February 2015

Photoelectron spectra, hyperconjugation, methylene derivatives

The photoelectron (PE) spectra of dicyano methane and of its dimethyl derivative are tentatively assigned on the basis of a simple MO model. The interactions defined therein between the two cyano groups as well as with the R2C-framework can be parametrized using the PE data. Thus the hyperconjugation πCN/πCR₂ is estimated to amount to 1.7 eV in both compounds. Hyperconjugative effects in methane derivatives H3CX and H2CX2 with X = Br, Cl and CN are compared.
Kernresonanzspektroskopische Untersuchungen an Hexafluordiazabiphenylen und 2.3.6-Trifluorpyridin-4.5-dicarbonsäurederivaten / NMR Spectroscopic Investigations on Hexafluorodiazabiphenylene and Derivatives of 2,3,6-Trifluoropyridine-4,5-dicarboxylic Acid
Authors: Hagele Gerhard , Sartori Peter , Golloch Alfred
Published: February 2015

Two isomers of hexafluorodiazabiphenylene were obtained via the pyrolysis of 2,3,6-trifluoropyridine-4,5-dicarboxylic acid disilver salt. Their [AMX]2 fluorine NMR spectra were recorded in Fourier transform technique, partially analyzed and correlated with the molecular symmetry of the isomers. Relative signs of nJFF in 2.3,6-trifluoropyridine-4,5-dicarboxylic acid were determined by nuclear Overhauser experiments.
Verhalten von Spiropyranschichten gegenüber thermischer Belastung / Behaviour of Spiropyran Films by Thermal Treatment
Authors: Arnold G. , Vollmer H.-P.
Published: February 2015

The influence of thermal treatment of photochromic spiropyran films has been investigated. The measurements demonstrate that the decompositions of the photochromic films and the different components are changed noticeable at temperatures of 100°C and above.
Massenspektrometrische Strukturaufklärung neuer Arginin-Antagonisten / Mass Spectrometric Structure Elucidation of New Arginine Antagonists
Authors: König Wilfried A.
Published: February 2015

The structure of two new arginine antagonists, isolated from microorganisms, was determined by mass spectrometry after formation of adequate derivatives and by comparison with derivatives of reference compounds.
The Coordination Chemistry of Phosphoryl Compounds Containing the -N(CH3)2 Group, XII.
Authors: Bolster M.W.G. De , Nieuwenhuijse B. , Reedijk J.
Published: February 2015

Room temperature electron spin resonance powder spectra have been recorded for some compounds of the type Mn(ligand)p(anion)2 with hexamethylphosphoramide and nonamethylimidodiphosphoramide as ligands (p = 1 - 4) and BF-4, NO-3, Cl-, Br-, I- and NCS-as anions.

The values for the zero-field parameters, D and λ, have been determined and are compared with literature data. It is shown that ESR spectroscopy can be very helpful in elucidating the structures of manganese(II) complexes.

The high values for the hyperfine coupling constant of the solvates suggest that in these complexes the bonding between the ligands and the metal ion is essentially ionic.
Aluminium(III) Derivatives of Monofunctional Bidentate Schiff Bases
Authors: Prasad R. N. , Tandon J. P.
Published: February 2015

Reactions of aluminium iso-propoxide with monofunctional bidentate Schiff bases having the general formula 2-HOC10H6CH:NR (where R = C2H5, n C3H7, iso-C3H7, n-C4H9, iso-C4H9, sec-C4H9, tert-C4H9 and C6H5) in different stoichiometric ratios have yielded Al(OPri)2(SB), Al(OPri)(SB)2 and Al(SB)3 type of products (where SB is the anion of the corresponding Schiff base, SBH). The ebullioscopic determination of molecular weights shows that the di-iso-propoxy mono- Schiff base derivatives are dimeric; the tris- Schiff base derivatives are monomeric and for the mono-iso-propoxy bis- Schiff base derivatives, molecular association is ~1.4. The IR spectra of a few representative derivatives have been recorded and possible structures indicated.
Magnetic Studies of Cerium Ammonium Sulphate in Relation to Crystal Structure
Authors: Singhal O. P.
Published: February 2015

The magnetic anisotropy and principal magnetic susceptibility of the single crystal of cerium ammonium sulphate has been measured and the results obtained have been discussed in the light of crystalline field theory. It has been observed that the cubic field in cerium ammonium sulphate is very much stronger and the contribution of the rhombic field is almost negligible. The predominance of the cubic field over the rhombic field may also be due to surrounding of the cerium ion by octahedron of water molecules with their negatively charged oxygen atoms pointing towards the central Ce
3+ ion. The relative orientation of the atomic groups with different ions in the unit cell makes the resultant anisotropy smaller.
Physikalische Eigenschaften kristallisierter Dichlorobis(isonitril)platin(II)-Komplexe / Physical Properties of Crystallized Dichloro(bis-isonitrile)platinum(II)complexes
Authors: Gitzel W. , Keller H. J. , Lorentz R. , Rupp H. H.
Published: February 2015

The properties of some new dichlorobis (aryl-isonitrile) platinum (II) complexes are given. The optical reflexion spectra of the compounds in their colored modification depend strongly on the strength of the intermolecular metal interactions. It is shown that the solid state properties are influenced heavily by the steric requirements of the isonitrile ligands.
Planare Dicarbonylrhodium(I)- und -iridium(I) -Komplexe mit polarisierbaren aromatischen Liganden / Planar Dicarbonylrhodium(I) and Iridium(I) Complexes with Polarizable Aromatic Ligands
Authors: Aderjan Rolf , Breer Hermann , Keller Heimo J. , Rupp Herbert H.
Published: February 2015

Some new transition metal complexes of the general type M(CO)2(L-L), where M stands for Ir(I), Rh(I) and L-L for a bidentate mononegative ligand are described. They were characterized by means of analytical data and their IR and PMR spectra. The chemical and solid state properties of these compounds are related to the strength of the intermolecular metal-metal interactions.
Metallkomplexe mit polymeren Liganden. II / Metal Complexes with Polymeric Ligands. II
Authors: Biedermann Hans G. , Wichmann Klaus
Published: February 2015

The compositions of some precipitations of CoCl2 and Ni J2 with poly-4-vinylpyridine in dependence on the temperature and the concentration of the poly-4-vinylpyridine solution in ethyl alcohol are determined and discussed.
Kontakt- und Pseudokontakt-Verschiebungen in den 1H- und 13C-NMR-Spektren des paramagnetischen Komplexes Tricyclopentadienyl-(cyclohexylisonitril)-europium(III) / Contact- and Pseudocontact Shifts in the 1H- and 13C-NMR Spectra of the Paramagnetic, Organometallic Complex Tricyclopentadienyl-(cyclohexylisonitrile)-europium(III)
Authors: Ammon Reinhard Von , Kanellakopulos Basil , Fischer R. Dieter , Formacek Viktor
Published: February 2015

The organometallic NMR shift reagent Eu(C5H5)3 induces large paramagnetic shifts in the 1H-NMR spectrum of cyclohexylisonitrile. The 1:1-adduct (C5H5)3Eu•CNC6H11 has been isolated. The dipolar nature of the paramagnetic shifts of some of the C6H11-protons in this complex is used to fractionate the shifts of the C5H5-nuclei (1H and 13C) into the dipolar and contact contributions. The positive sign of the 13C contact shift is in accord with the usual spin alignment of the free europium ion relative to the external field together with a negative coupling constant. The opposite sign of the 1H contact shift is explained by a polarization mechanism. The anomalous temperature dependence of the 1H contact shift is connected with the strong second order paramagnetism of the europium ion.
Zur Chemie von Uranylvanadaten mit Trimetavanadationen und Schichtstruktur (Uvanit) / The Chemistry of Uranylvanadates with Trimetavanadate Ions and Layer Structure (Uvanite)
Authors: Hilke Klaus Jürgen , Grosse-Brauckmann Ulrich , Lagaly Gerhard , Weiss Armin
Published: February 2015

Synthesis and properties of an uranylvanadate (Mz+
1/z (H2O)π [UO2V3O9]-) with trimetavanadate ions are described. The compound has a layer structure with [UO2V3O9]--layers of about 6.5 Å thickness. The layers are identical with the U, V-layers in natural uvanite. The cations Mz+ between the [UO2V3O9]--layers can be exchanged against inorganic and organic cations. The water molecules can be replaced by other solvent molecules (nitromethane, acetonitrile, dimethylsulfoxide, N-methylformamide, ethylene glycol etc.) under formation of distinct layer solvates. Reversible dehydration of the hydrates between 100° and 500°C leads to regular displacements of the uvanite layers to each other.
Intercalation von n-Alkylaminen in TiS2
Authors: Weiss Armin , Ruthardt R.
Published: February 2015

Intercalation compounds with the limiting composition (n - CnH2n+1NH2)x · TiS2 with x = 0.95 - 1.02 for n = 4 - 10 and x = 1.05 for n ≥ 16 are formed from crystalline titaniumdisulfide and liquid n-alkylamine. The guest molecules are arranged in bimolecular layers between the layers of the host lattice; the tilting angle of n-alkylchains from 4 to 9 carbon atoms per chain is 56°; with 16 or more carbon atoms in the chain they stand perpendicular to the layers of the host lattice. With intermediate chain lengths random sequencies of both structures have been observed. Preparation of the compounds is facilitated by a two-step reaction:
ESCA- Untersuchungen an Eisen-Schwefelverbindungen
Authors: Binder Herbert
Published: February 2015

The ionization energies of some iron-sulphur compounds are reported and discussed. The nature of the chemical bond between iron and sulphur varies between ionic and practically pure covalent. Multiplet-splittings in the Fe3s level are observed in the photoionization resulting from the spin orientation of the 3d electrons. Satellite lines, which can be explained in terms of a shake-off process, were observed for the first time in the Fe2p and Fe3p levels of KFeS2. Some of the investigated compounds show satellite lines in the Fe2p level; these can be accounted for in terms of valence electron excitations.
Über Erdalkali-Oxoargentate. II Zur Kenntnis von BaAg6O4 / About Alkaline Earth-Oxoargentate. II About BaAg6O4
Authors: Keller H.-L. , Müller-Buschbaum Hk.
Published: February 2015

The hitherto unknown compound BaAg6O4 was prepared by high pressure reactions. A single crystal X-ray examination made obvious that the BaAg6O4 compound is isotypic with the compound SrAg6O4. A detailed discussion of the relations between the structures of BaAg6O4, Ag2O, BaCu2O2 and BaO is given.
Chelating Tendencies of Some N-(2-Acetyl-1,3-Indandione) Trialkyl Ammonium Iodides with Transition Metal Ions
Authors: Bachlaus M. K. , Menaria K. L. , Nath P.
Published: February 2015

The ligands T.P.A.I.* and T.B.A.I.** have been synthesised and their dissociation constants are 1.738 · 10-10 and 1.412 · 10-8 respectively. The potentiometric studies show that these reagents form 1 : 1 complex with copper(II) and iron(II). The stability constants of copper complex and iron complex with T.P.A.I. are 6.43 and 6.51 respectively and for T.B.A.I. 4.36 and 4.24 respectively. The free energy of complex formation at 25°C are 8.76 Kcal/mole and 8.87 Kcal/mole for Cu (II)-T.P.A.I. and Fe (II)-T.P.A.I. respectively, whereas the free energy of the Cu (II)-T.B.A.I. and Fe(II)-T.B.A.I. are 5.94 Kcal/mole and 5.78 Kcal/mole respectively.
Photochemischer Abbau N-substituierter O-Alkylurethane / The Photolysis of N-Substituted O-Alkylurethanes
Authors: Schultze Hartmut
Published: February 2015

The photolysis of N-aryl-carbamic acid alkyl esters in methanol was investigated. The primary products, amino-benzoic acid esters and aromatic amines, result from photo-Fries rearrangements and splitting processes.

2,4,6-Trimethylphenyl-carbamic acid ethyl ester and N-alkyl-carbamic acid alkyl esters form photolysis products only through homolytic splitting reactions.

The photooxidation of N-substituted urethanes has been investigated in tert.-butanol. The main products are primary amines and CO2.

These initially formed compounds are then further oxidized. In the aliphatic substituted derivatives, oxidation of the N-alkyl group results followed homolytic bond splitting.
Spektroskopische Untersuchungen in der Festkörperchemie
Authors: Burkert Paul K. , Eckel Max F.
Published: February 2015

185Re,187Re-NQR-spectra of polycrystalline NH4ReO4 and ND4ReO4 show a strong temperature dependence of their transition frequencies with anomalous positive temperature coefficients in contrast to the behaviour of other measured perrhenates.

The positive values of the temperature coefficients are explained by an additional intermolecular interaction of the cations with ReO4-, which strengthens the intramolecular mechanism of reducing π-bond character with temperature.
Untersuchungen an biochemisch wirksamen Ligandensystemen, VIII
Authors: Fleischmann Wolf-Dieter , Fritz Heinz P.
Published: February 2015

The complexes ML2 (M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), LH = formylferrocenethiosemicarbazone) and Cu2L2 are described.

Their IR- and UV-spectra and their polarographic behaviour are reported.
Zur Chemie von Uranglimmern mit Trimetavanadationen und Schichstruktur (Uvanit), II / The Chemistry of Uranylvanadates with Trimetavanadate Ions and Layer Structure (Uvanite), II
Authors: Beneke Klaus , Grosse-Brauckmann Ulrich , Lagaly Gerhard , Weiss Armin
Published: February 2015

The interlayer cations of uvanite can be exchanged quantitatively by n-alkylammoniumions according to

M+[UO2V3O9] + CnH 2n+1NH3
+⇄ CnH2n+1NH3[UO2V3O9] + M+.

In the stoichiometric compounds the alkyl chains of the cations (n= 6-18) are poorlyordered in monolayers and oriented nearly perpendicular to the uranyltrimetavanadatelayers though the space filling is unfavorable with this arrangement. During the cationexchange at pH = 7-9 additional free amine molecules are taken up yielding 1:1 intercalationcomplexes

(CnH2n+1NHs) (CnH an+1NH2) [UO2V3O9]

with close-packed, well ordered monolayers of alkyl compounds. With excess of pureamines or pure alkanols 1: 3 intercalation complexes

(CnH2n+1NH3) (CnH2n+1NH2),[UO2V3O9] or

(CnH2n+1NH3) (Cn·H2n+1OH )s[UO2V3O9

(n, n′ = 6-18] are formed with the alkyl chains ordered to bimolecular layers. These

complexes rearrange at higher temperature into new phases as a consequence of rotationalisomerisation of the alkyl chains.
Die Kristallstruktur von Methylquecksilberazid / The Crystal Structure of Methyl Mercury Azide
Authors: Müller Ulrich
Published: February 2015

CH3HgN3 crystallizes in the space group P21/c with four molecules per unit cell. The structure was solved by common crystallographic methods using X-ray diffraction data that were collected at a temperature of 100°K. The cooling was necessary to limit the radiation damage of the crystals. The molecules possess an essentially linear C-Hg-N group; in the crystals they are associated to layers bearing the methyl groups on their outer side.
Studies on Ylides: Carbonyl Olefination with p-Chlorobenzylidenetriphenylphosphorane
Authors: Kendurkar P. S. , Tewari R. S.
Published: February 2015

Preparation of p-chlorobenzylidenetriphenylphosphorane and its carbonyl olefination with a series of substituted aromatic aldehydes and 9-fluorenone are described. IR and NMR spectra of the resulting olefins were studied. Acylation of p-chlorobenzyliden-etriphenylphosphorane afforded a new disubstituted ylide.
Kinetics of the Oxidation of Ethylene Diamine Tetra Acetic Acid by Chloramine-T
Authors: Sanehi Ram , Mehrotra R. M. , Mushran S. P.
Published: February 2015

The kinetics of the oxidation of ethylene diamine tetra acetic acid (EDTA) by chloramine-T in acidic media has been investigated. The reaction shows first order dependence in chloramine-T and the order in hydrogen ion and substrate is fractional. On the basis of kinetic results a plausible mechanism is suggested. Activation parameters have also been calculated.
Syntheses of Spin-Labeled Phosphorus Compounds
Authors: Sosnovsky George , Konieczny Maria
Published: February 2015

Synthesis of the following classes of spin-labeled phosphorus compounds are described.

where R and R’ are either alkyl, cycloalkyl, glucosyl or phenyl, and Ṙ is the nitroxyl moiety. The epr of these compounds can be used as a tool for determining the number of nitroxyl moieties attached to the phosphorus atom, since all monoradicals have threeline spectra with aN 14.7-16.0G, all diradicals have five-line spectra with aN 7.5-8.3G, and all triradicals have seven-line spectra with aN 4.5-5.0 G. All of these compounds are well defined oils or solids, and can serve as model systems for the preparation of spin-labeled phosphorus compounds of biological interest.
The Crystal Structures of U2Cu9Al and UCu3,5Al1,5
Authors: Blažina Ž. , Ban Z.
Published: February 2015

Two new ternary phases were found by substituting copper with aluminium in the binary phase UCu5. Their compositions were determined as U2Cu9Al and UCu3,5Al1,5. X-ray powder diffraction investigations showed that the first one is hexagonal (S. G. P63/mmc, No. 194, MgZn2 type) with a = 4.998 = 0.005 A, c = 9.040 ∓ 0.005 Å and c/a = 1.809, Z = 1. UCu3,5Al1,5 is also hexagonal but it belongs to the space group P6/mmm (No. 191, CaCu5 type). The lattice parameters are a = 5.083 ∓ 0.005 Å, c = 4.155 ∓ 0.005 A and c/a = 0.817, Z = 1. In both structures atomic positions were determined by the trial and error method.
Darstellung, Schwingungsspektren und Normalkoordinatenanalyse der Ionen GeS4
4- und SnS4
4- / Preparation, Vibrational Spectra and Normal Coordinate Analysis of the Ions GeS4
4- and SnS4
4-
Authors: Pohl Siegfried , Schiwy Willy , Weinstock Nicodemo , Krebs Bernt
Published: February 2015

The preparation of the pure thio-anions GeS4
4- and SnS4
4- in aqueous solution is described. The vibrational spectra of the ions are reported and used for a normal coordinate analysis. The stretching force constant of GeS4
4- is very similar to the value of the isoelectronic AsS4
3- (M.V.F.F.: 2.12 vs 2.13 mdyn/Å). whereas the SnS4
4- stretching constant is significantly lower than the value of SbS4
3- (1.75 vs 2.09 mdyn/ Å).
Spektroskopische Untersuchungen in der Festkörperchemie, VIII / NQR-Investigations on Rhenium(VII)Oxide Re2O7
Authors: Burkert Paul K. , Eckel Max F.
Published: February 2015

A strong asymmetry in the electronic charge distribution on the central metal of Re2O7 is caused by bridging oxygen atoms. This asymmetry is measured by determining the 185Re, 187Re-NQR transitions, NQR coupling constants and asymmetry parameter.
Die Reaktion von NH2Cl mit Übergangsmetallen der IV. bis VI. Nebengruppe / The Reaction of NH2CI with Transition Metals of Group IV to VI
Authors: Fritz Heinz P. , Treptow Wolfram
Published: February 2015

NH2Cl and NH4X react with transition metals of group IV to VI forming nitrides at relatively low temperatures. TiN-coated titanium is tested for its use in lead accumulators.
Li3Al2, eine neue Phase im System Li/Al / Li3Al2, a New Phase in the System Li/Al
Authors: Tebbe Karl-Friedrich , Schnering Hans Georg , Rüter Barbara , Rabeneck Gisela
Published: February 2015

Besides ‘Li2Al’ which was recently shown to be the phase Li9Al4 there exists the phase Li3Al2 characterized by preparation and X-ray diffraction methods. It cristallizes with a rhomboedric unit cell, R3̄m, a = 4.508 Å, c = 14.26 Å and z = 3 formula units (hexagonal setting). The structure can be looked at as a variant of the body centred cubic packing with Αl-atom layers of puckered six membered rings. The structural relation of the phases LiAl, Li3Al2, Li9Al4, Li is discussed.
Optisch aktive Übergangsmetall-Komplexe, XXII
Authors: Brunner Henri , Herrmann Wolfgang A.
Published: February 2015

Upon irradiation of C5H5V(CO)4 in the presence of the Schiff base, derived from pyridine-carbaldehyde (2) and S-(—)-α-methylbenzyl-amine, two cis CO groups are replaced by the chelating ligand with the formation of complex 3. The reaction of C5H5W(CO)3Cl with 8-hydroxy-quinoline in boiling THF yields the oxinato complex 4. The analogous compound 5 is obtained in the reaction of C5H5Mo(CO)3Cl with 7-carboxy-8-hydroxyquinoline.

The new asymmetric complexes with square pyramidal structure are characterised by C, H, N analyses, molecular weight determinations, IR, 1H NMR, UV and mass spectra.
Facile Preparation of Benzyl β-Glycosides of 2-Acylamino-2-deoxy-ᴅ-glucopyranoses
Authors: Rhoads William D. , Gross Paul H.
Published: February 2015

Benzyl β-ᴅ-glycosides of 2-acylamino-2-deoxy-ᴅ-glucopyranose are usually prepared by multistep processes employing the glycosyl halides. Mixtures of benzyl glycosides which contain predominantly the α-glycoside result from acid catalyzed reactions with benzyl alcohol in one phase. In a two phase system, however, the lower solubility of the β-ᴅ-anomer becomes the determining factor in the resultant tandem equilibrium, and the β-ᴅ-glycoside predominates in the final product.
Zur Prototropie von Phaeophytin a / On the Prototropy of Pheophytin a
Authors: Zanker Valentin , Rudolph Ernst , Hindelang Fritz
Published: February 2015

Additionally to the neutral and dicationic configuration for pheophytin a the monocation and monoanion can also be determined and characterized by means of absorption and fluorescence polarisation spectroscopy, by its relative aqueous solubility, and by its behavior in the electric field. The typical absorption- and APF-spectra for these prototropic configurations exist at the following normalities: > 2N HCl(pK ≈0) for the dication, 1.0-1.7 N HCl(pK ≈ 1.6) for the monocation, 0.1ɴ HCl—0.0003ɴ NaOH for the neutral configuration, and 0.3ɴ NaOH(pK ≈8,5) for the monoanion. Due to the quickly starting secondary reactions at elevated alkaline pH, the diaions cannot be proved definitely. At the transition monoanion →neutral configuration → monocation → dication, the position of the red band remains nearly constant (changes being < 150 cm-1); in contrast, the bands 2 and 3 as well as the Bx and By transition of the Soret band are considerably shifted bathochromatically (1200-2000 cm-1); from this fact it may be concluded that there is an inner ring oscillator with participation of the N-atoms. In the same sequence the intensity of band 3 decreases by approx. 40% and that of band 2 increases by the same value; in the ionic state the intensity of the red band and Soret band is at a maximum.
13C-NMR-Spektren p-substituierter Phenylcyclobutadien-eisentricarbonyle / 13C-MRR-Spectra of p-Substituted Cyclobutadiene-irontricarbonyls
Authors: Brune Hans Albert , Horlbeck Gernot
Published: February 2015

The electronic interaction between complex bonded cyclobutadiene and the phenyl ring is analyzed by 13C- and 1H-NMR-spectra. The cyclobutadiene-irontricarbonyl acts electron donating via the π-system and electron accepting via the σ-core.
Substituenteneffekte im spektroskopischen Verhalten von Maleinsäurederivaten und 4-Cyclopenten-1.3-dionen / Substituent Effects on the Spectroscopic Behavior of Maleic Acid Derivatives and 4-Cyclopentene-1,3-diones
Authors: Scharf Hans-Dieter , Leismann Hans
Published: February 2015

The lowest excited states of maleic acid- and cyclopentendionderivatives have been investigated by UV-absorption and phosphorescence emission spectroscopy. While the first excited singlet-state S1 is of 1(nπ*)-type in all compounds, the lowest triplet-state T1 was found to be a mixture of 3(nπ*) and 3(ππ*)-configurations. For the emitting derivatives (Ζ ≠ Η) phosphorescence-lifetimes and -quantum yields as well as the probability for intersystem crossing have been determined.

Considering the inductive effects of all substituents on the S1 (nπ*) -energy, Coulombpotentials for sulfur and iodine in terms of Huckel-parameters: hs = 0,2 and hj = —0,5 have been derived.

The results of Hückel-MO-calculations can be correlated to the measured values of all compounds with the exception of the iodine containing derivatives.
Enhanced GABAergic Inputs Contribute to Functional Alterations of Cholinergic Interneurons in the R6/2 Mouse Model of Huntington’s Disease
Authors: Holley Sandra M. , Joshi Prasad R. , Parievsky Anna , Galvan Laurie , Chen Jane Y. , Fisher Yvette E. , Huynh My N. , Cepeda Carlos , Levine Michael S.
Published: February 2015

In Huntington’s disease (HD), a hereditary neurodegenerative disorder, striatal medium-sized spiny neurons undergo degenerative changes. In contrast, large cholinergic interneurons (LCIs) are relatively spared. However, their ability to release acetylcholine (ACh) is impaired. The present experiments examined morphological and electrophysiological properties of LCIs in the R6/2 mouse model of HD. R6/2 mice show a severe, rapidly progressing phenotype. Immunocytochemical analysis of choline acetyltransferase-positive striatal neurons showed that, although the total number of cells was not changed, somatic areas were significantly smaller in symptomatic R6/2 mice compared to wild-type (WT) littermates, For electrophysiology, brain slices were obtained from presymptomatic (3-4 weeks) and symptomatic (>8 weeks) R6/2 mice and their WT littermates. Striatal LCIs were identified by somatic size and spontaneous action potential firing in the cell-attached mode. Passive and active membrane properties of LCIs were similar in presymptomatic R6/2 and WT mice. In contrast, LCIs from symptomatic R6/2 animals displayed smaller membrane capacitance and higher input resistance, consistent with reduced somatic size. In addition, more LCIs from symptomatic mice displayed irregular firing patterns and bursts of action potentials. They also displayed a higher frequency of spontaneous GABAergic IPSCs and larger amplitude of electrically evoked IPSCs. Selective optogenetic stimulation of somatostatin- but not parvalbumin-containing interneurons also evoked larger amplitude IPSCs in LCIs from R6/2 mice. In contrast, glutamatergic spontaneous or evoked postsynaptic currents were not affected. Morphological and electrophysiological alterations, in conjunction with the presence of mutant huntingtin in LCIs, could explain impaired ACh release in HD mouse models.
Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) Deficiency Attenuates Phagocytic Activities of Microglia and Exacerbates Ischemic Damage in Experimental Stroke
Authors: Kawabori Masahito , Kacimi Rachid , Kauppinen Tiina , Calosing Cyrus , Kim Jong Youl , Hsieh Christine L. , Nakamura Mary C. , Yenari Midori A.
Published: February 2015

Clearing cellular debris after brain injury represents an important mechanism in regaining tissue homeostasis and promoting functional recovery. Triggering receptor expressed on myeloid cells-2 (TREM2) is a newly identified receptor expressed on microglia and is thought to phagocytose damaged brain cells. The precise role of TREM2 during ischemic stroke has not been fully understood. We explore TREM2 in bothin vitroandin vivostroke models and identify a potential endogenous TREM2 ligand. TREM2 knockdown in microglia reduced microglial activation to an amoeboid phenotype and decreased the phagocytosis of injured neurons. Phagocytosis and infarcted brain tissue resorption was reduced in TREM2 knock-out (KO) mice compared with wild-type (WT) mice. TREM2 KO mice also had worsened neurological recovery and decreased viable brain tissue in the ipsilateral hemisphere. The numbers of activated microglia and phagocytes in TREM2 KO mice were decreased compared with WT mice, and foamy macrophages were nearly absent in the TREM2 KO mice. Postischemia, TREM2 was highly expressed on microglia and TREM2-Fc fusion protein (used as a probe to identify potential TREM2 binding partners) bound to an unknown TREM2 ligand that colocalized to neurons. Oxygen glucose deprivation-exposed neuronal media, or cellular fractions containing nuclei or purified DNA, but not cytosolic fractions, stimulated signaling through TREM2. TREM2-Fc fusion protein pulled down nucleic acids from ischemic brain lysate. These findings establish the relevance of TREM2 in the phagocytosis of the infarcted brain and emphasize its role in influencing neurological outcomes following stroke. Further, nucleic acids may be one potential ligand of TREM2 in brain ischemia.