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Facet section ZfN Section B:Volume 036 [X]

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201	Author		Requires cookie*
	Title	Die Struktur der bei der Korrosion von Kupfer in Gegenwart von 2-Aminopyrimidin (Sauerstoff, NaCl, pH 4,1, 22 °C) aufgebauten Schutzschicht
	Reference	Z. Naturforsch. 36b, 989 (1981)
	Published	1981
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	Identifier	ZNB-1981-36b-0989
	Volume	36

202	Author	Hermann Lotter	Requires cookie*
	Title	{Configurations*-Bestimmung von Isomeren des Methyl 4-0-Acetyl-2.3-0-(l-phenylethyliden)-a-L-rhamnopyranosides [1] The Configuration of Isomeres of Methyl 4-0-Acetyl-2,3-0-(l-phenylethylidene)-a-L-rhamnopyranoside [1]
	Abstract	Diastereomeric 2,3-0[2-Phenyl-2-methyl-l,3 dioxalanes], X-ray The diastereomeric 2,3-0-[2-phenyl-2-methyl-l,3 dioxalanes] of methyl-a-L-rhamno-pyranosides were synthesised for the first time. The stereochemical characterisation was carried out by X-ray analysis. Evaluation of the X-ray data and comparison with NMR data indicated that the same configuration exists in the crystalline state as in solution.
	Reference	Z. Naturforsch. 36b, 997—999 (1981); eingegangen am 26. März 1981
	Published	1981
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	Identifier	ZNB-1981-36b-0997
	Volume	36

203	Author	PaavoH. Hynninen, Gunnel Sievers	Requires cookie*
	Title	Conformations of Chlorophylls a and a' and their Magnesium-Free Derivatives as Revealed by Circular Dichroism and Proton Magnetic Resonance
	Abstract	The electronic absorption (UV/VIS), circular dichroism (CD) and proton magnetic resonance (*H NMR) spectra have been recorded for C-l0 epimeric chlorophylls a and a', pheophytins a and a' as well as pheophorbides a and a'. Although the epimers in each pair showed virtually identical UV/VIS spectra, their CD spectra were profoundly different and exhibited opposite signs at most wavelengths in the UV region. The differences were interpreted as arising, in part, from different C-10 configurations, and, in part, from conformational alterations induced by the steric strain in the crowded periphery of the macrocycle. The conformational alterations were also clearly indicated by the X H NMR zJö-values observed for the a,ß and <5 methine protons, the C-10 protons and most methyl group protons of the epimers in each pair. This was considered to imply changes in the geometry of the whole macrocycle. The A 6-values were larger for the Mg-free epimers than for the chlorophyll epimers, which shows that the central Mg-atom makes the macrocycle more rigid. Correlations between the signs of the CD bands and configurations are discussed.
	Reference	Z. Naturforsch. 36b, 1000—1009 (1981); received May 19 1981
	Published	1981
	Keywords	Stereochemistry, Conformational Analysis, Chlorophyll and Pheophytin Epimers, X H NMR Spectra, Circular Dichroism
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	Identifier	ZNB-1981-36b-1000
	Volume	36

204	Author	PaavoH. Hynninen	Requires cookie*
	Title	Mechanism of the Allomerization of Chlorophyll: Inhibition of the Allomerization by Carotenoid Pigments
	Abstract	Autooxidation of Chlorophyll, Free Radicals, Carotenoids, Photosynthesis It is shown that the allomerization of chlorophylls a and b is effectively inhibited by carotenoid pigments. In the light of this finding, two possible mechanisms are considered for the allomerization. One assumes the addition of singlet oxygen to the 9,10-double bond of the chlorophyll (Chi) enolate anion to yield a C-10 hydroperoxide or a dioxetane derivative. The other assumes a free-radical chain reaction involving Chi enolate anion, triplet oxygen, Chi C-10 radicals and peroxide radicals, and Chi C-10 hydroperoxide. The observation that the allomerization and its inhibition by carotenoids occur under carefully controlled dark conditions precluding singlet oxygen formation provides substantial support to the latter mechanism. Further evidence for the free-radical mechanism is obtained by observing the increase of the allomerization rate when air is replaced with pure oxygen from a container. The rate increases to about two-fold in the methanolic Chi solution containing no carotenoid but remains close to zero in the Chi solution containing an equimolar amount of ^-carotene. The relevance of the results to photosynthesis and cancer research is briefly discussed.
	Reference	Z. Naturforsch. 36b, 1010—1016 (1981); received May 19 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1010
	Volume	36

205	Author	Herbert Meier, Johannes Zountsas, Oswald Zimmer	Requires cookie*
	Title
	Abstract	A X H and 13 C NMR spectroscopical study is performed on the basis of 37 1,2,3-selena-diazoles. Besides the discussion of chemical shifts and coupling constants of X H and 13 C, selenium satellites were measured providing 1 H 77 Se and 13 C 77 Se coupling constants.
	Reference	Z. Naturforsch. 36b, 1017—1022 (1981); eingegangen am 16. April 1981
	Published	1981
	Keywords	NMR Spectra, 1, 2, 3-Selenadiazoles, 77 Se Coupling
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	Identifier	ZNB-1981-36b-1017
	Volume	36

206	Author	-, Gerhard Nonnenmacher, Gottfried Zimmermann®, Otto Isaac»	Requires cookie*
	Title	Elmar Flaskamp
	Abstract	The stereochemistry of the bisaboloids in chamomile—with the exception of bisabolol-oxide C—has been elucidated. The in-vitro-examination of the mutual convertibüities of some bisaboloids gave evidence for the stereochemical accordance of the common chiral centres of all the bisaboloids. The absolute configurations of the remaining third asym-metric carbon atoms in bisabololoxide A and B have been determined by NMR spectro-metric studies in comparison with their unnatural semisynthetic epimers. All the stereo-genie centres of the bisabololoxides A and B, of (—)-a-bisabolol and of bisabolonoxide A turn out to be S-configurated.
	Reference	Z. Naturforsch. 36b, 1023—1030 (1981); eingegangen am 30. April 1981
	Published	1981
	Keywords	Matricaria chamomilla L, Bisaboloids, 13 C NMR Spectra, Shift-Reagents
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	Identifier	ZNB-1981-36b-1023
	Volume	36

207	Author	Wolf-H Gündel	Requires cookie*
	Title	Untersuchungen an quartären Pyridinium-Salzen, XTV [1] Dihydropyridyl-oxiinether Investigations of Quaternary Pyridinium Salts, XIV [1] Dihydropyridyl-oxime-ethers
	Abstract	Pyridinium Salts with electron-withdrawing groups in the 3-position react with aliphatic ketoximes under basic conditions to lipophilic addition products, 6-(alkylideniminoxy)-1,6-dihydropyridines.
	Reference	Z. Naturforsch. 36b, 1031—1036 (1981); eingegangen am 21. April 1981
	Published	1981
	Keywords	Pyridinium Salts, Insertion Reaction, Oximes
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	Identifier	ZNB-1981-36b-1031
	Volume	36

208	Author	Römer, H. Scholl, H. Budzikiewicz, H. Korth, G. Pulverer	Requires cookie*
	Title	A
	Abstract	The structure elucidation of several minor phenazine pigments of Pseudomonads is described. 4-Hydroxyphenazine-l,6-dicarboxylic acid dimethyl ester, 2,3-dihydroxy-phenazine, 2,3,7-trihydroxyphenazine, 4-hydroxyphenazine-l-carboxylic acid, 2,3-di-hydroxyphenazine-l-carboxylic acid, 2,6-dihydroxyphenazine-l-carboxylic acid and 2,3,7-trihydroxyphenazine-l,6-dicarboxylic acid are new phenazine derivatives. The distribu-tion of phenazines in the genus Pseudomonas is investigated.
	Reference	Z. Naturforsch. 36b, 1037—1046 (1981); eingegangen am 27. März 1981
	Published	1981
	Keywords	Phenazines, Bacterial Constituents, Pseudomonads, NMR Spectra, IR Spectra
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	Identifier	ZNB-1981-36b-1037
	Volume	36

209	Author	Masaru Ishida, Shinzi Kato, Masateru Mizuta	Requires cookie*
	Title	The Reaction of Dithiocarboxylic Acids with Imines
	Abstract	Aromatic dithiocarboxylic acids 1 react with imines 4 to give the corresponding adducts 5, aminomethyl dithiocarboxylates, in good yields. The adducts 5 react with phenacyl bromide to give the corresponding phenacyl dithiocarboxy-lates 6. We have previously reported that the reaction of dithiocarboxylic acids (1) with various kinds of secondary and tertiary amines gave the correspond-ing salts (2) in excellent yields [1]. Recently,
	Reference	Z. Naturforsch. 36b, 1047—1049 (1981); received April 29 1981
	Published	1981
	Keywords	Aryl Dithiocarboxylic Acids, Imines, Aminomethyl Dithiocarboxylates, Phenacyl Dithiocarboxylates
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	Identifier	ZNB-1981-36b-1047_n
	Volume	36

210	Author	PeterG. Jones, Einhard Schwarzmann, GeorgeM. Sheldrick, Harald Timpe	Requires cookie*
	Title	Darstellung und Struktur von Di-gold(III)bis(selenit)(diselenit), Au2(Se0 3 )2(Se 2 05) Preparation and Crystal Structure of Di-gold(III)bis(selenite) Diselenite, Au2(Se0 3 )2(Se 2 05)
	Abstract	The compound Au 2 (Se0 3) 2 (Se 2 0s) was pre-pared from gold metal and seienic acid at 553 K. The crystal structure [C2/c, a = 2034.4(5), b = 413.0(1), c = 1325.4(3) pm, ß = 115.88(3)°, Z = 4] was refined to R = 0.035. Both gold atoms lie on crystallographic centres of sym-metry and show square planar coordination (Au-0 196.9-201.3 pm). The extended structure consists of three cross-linked systems of the form [ • • • -Au-(selenite or diselenite) -Au----].
	Reference	Z. Naturforsch. 36b, 1050—1051 (1981); eingegangen am 19. Mai 1981
	Published	1981
	Keywords	Sealed-tube Synthesis, Crystal Structure, Selenite Ligand, Diselenite Ligand
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	Identifier	ZNB-1981-36b-1050_n
	Volume	36

211	Author	Ernst Guggolz, ManfredL. Ziegler, Willibald Kalcher, Johann Plank, Doris Riedel, WolfgangA. Herrmann	Requires cookie*
	Title	Synthese und Molekülstruktur der dreikernigen Cluster-Verbindung (^-C5Me5)IrFea(CO)9 Synthesis and Molecular Structure of the Trinuclear Cluster Compound (^ 5 -C5Me5)IrFe2(CO)g
	Abstract	Reaction of triirondodecacarbonyl (1) with the dinuclear chloroiridium complex [(?? 5 -C5Me5)Ir(//-Cl)Cl]2 (2) in benzene at 50 °C yields the novel mixed iron iridium cluster of composition (rj 5 -C&Mes)IrFe2(C0)9 (8) the molecular structure of which has been established by X-ray diffraction methods. The mononuclear half-sandwich complex (j7 5 -C5Me5)Ir(CO)2 (4) present in the reaction mixture was found to represent the immediate precursor of the cluster compound 8.
	Reference	Z. Naturforsch. 36b, 1053—1059 (1981); eingegangen am 8. April 1981
	Published	1981
	Keywords	Iron, Iridium, Carbonyl Complexes, Pentamethylcyclopentadienyl
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	Identifier	ZNB-1981-36b-1053
	Volume	36

212	Author	Ernst Guggolz, Franz Oberdorfer, ManfredL. Ziegler	Requires cookie*
	Title	in Gegenwart von Cyclooctatetraen und 1.3-Butadien Photochemical Reactions of Re2(CO)io in the Presence of Cyclooctatriene and 1,3-Butadiene
	Abstract	Rhenium Carbonyl Olefin Complexes Re2(CO)io has been photolyzed in the presence of cyclooctatetraene, 1,3-butadiene and 1,4-pentadiene, respectively. In pentane solutions the species (CO)4Re-/i-(^ 3 :^ 1 -C4He)Re(CO)5, (CO)4Re-/i-(t? 2 :7] 2 -C4H6)Re(CO)4 (11) and HRe3(CO)i4 could be isolated with 1,3-butadiene. C8H8 yielded several compounds of which the following could be unequivocally charac-terized (CO)4Re-//-(r?3:^i.C8H8)Re(CO)5 (14), (^-CgHsJRefCOh-MU.S-^rö-^-CgHs)-Re(CO)4 and (CO)3Re-//-(j? 4 :77 4 -C8H8)Re(CO)3.11 and 14 have been characterized by X-ray structure analysis.
	Reference	Z. Naturforsch. 36b, 1060—1068 (1981); eingegangen am 22. Juni 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1060
	Volume	36

213	Author	Alois Haas, Reiner Hitze	Requires cookie*
	Title	Darstellung und Charakterisierung von Cyclotri(silaselan) (H2Si-Se)3 Preparation and Characterisation of Cyclotri(silaselane) (H2Si-Se)3
	Abstract	Cyclotri (silaselane), Polymerisation In benzene HgSe reacts with H2SÜ2 at 120 °C to yield a polymer, which on heating in benzene depolimerizes to form (H2SiSe)3. 1 H, 29 Si, 77 Se, NMR, IR and MS data are presented.
	Reference	Z. Naturforsch. 36b, 1069—1070 (1981); eingegangen am 18. Mai 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1069
	Volume	36

214	Author	Werner Storzer, Dietmar Schomburg, Gerd-Volker Röschenthaler	Requires cookie*
	Title	Darstellung von 2-Amino-1.3.2;> 3 (A 5 )-dioxaphospholanen Synthesis of 2-Amino-1,3,2A 3 (A 5 )-dioxaphospholanes
	Abstract	2-Amino-4,4,5,5-tetrakis(trifluoromethyl)-1,3,2 A 3 (A 5)-dioxaphospholanes, Oxidative Addition, Dilithiumperfluoropinacolate
	Reference	Z. Naturforsch. 36b, 1071—1079 (1981); eingegangen am 29. Mai 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1071
	Volume	36

215	Author	Gerd Becker, Angelika Münch, Hans-Jürgen Wessely	Requires cookie*
	Title	Acyl-und Alkylidenarsane, V [1] (Dimethylaminomethyliden)-phenylar8an, ein acyclisches Alkylidenarsan Acyl-and Alkylidenearsines, V [1] (Dimethylaminomethylidene)-phenylarsine, an Acyclic Alkylidenearsine
	Abstract	Alkylidenearsines, Aminomethylidenearsines, Barrier of Rotation In the absence of a catalyst phenyl-bis(trimethylsilyl)arsine (1 a) reacts only very slowly with excess dimethylformamide (4) to give (dimethylaminomethylidene)-phenylarsine (8 a) and hexamethyldisiloxane (5). In the presence of small amounts of solid sodium hydroxide, however, the reaction is already finished after four days at + 20 °C. Similarly, lithium phenyltrimethylsilylarsenide • DME (2a), which can easily be obtained from la and methyllithium in 1,2-dimethoxyethane (DME), and dimethylformamide (4) also form the alkylidenearsine (3 a) and lithium trimethylsilanolate. The NMR spectra of 3 a show the rotation of the dimethylamino group to be hindered with a barrier of about 63 kJ • mol -1 .
	Reference	Z. Naturforsch. 36b, 1080—1084 (1981); eingegangen am 7. April 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1080
	Volume	36

216	Author		Requires cookie*
	Title	\s = C
	Abstract	\ H • (CH 3) 3 Si-0-Li U) N(CH 3) 2 c5H5 \ /\ / (CH3)2N As NICH3)2 C 6 H 5 (3) 6a 3a DME = 1.2-Dimethoxyethan Das ebenfalls gebildete Lithium-trimethylsilanolat (7) wird durch Zugabe von Chlortrimethylsilan zu Hexamethyldisiloxan (5) umgesetzt. Nach Filtration und destillativer Aufarbeitung isoliert man 3 a mit 85-proz. Ausbeute. Wie bei der vorherigen Um-setzung kann auch hier das Dimere 6 a nicht mehr nachgewiesen werden. Die von Oehme und Mitarb. beschriebene Darstellung des (Dimethylamino-methyliden)-phenylphosphans aus Phenylphosphan und dem Dimethylacetal des Dimethylformamids [25] konnte auf Phenylarsan bisher nicht übertragen werden. Beim Vermischen der Komponenten bildet sich eine kristalline Verbindung, deren Konstitution noch aufgeklärt werden muß.
	Reference	Z. Naturforsch. 36b, 1081 (1981)
	Published	1981
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	Identifier	ZNB-1981-36b-1081
	Volume	36

217	Author	Ralf Steudel, Eva-Maria Strauss	Requires cookie*
	Title	Nachweis von Se6, Se7 und Se8 in Lösungen yon Selen mittels Hochdruckflüssigkeitschromatographie Detection, of See, Se7 and Ses in Selenium Solutions by High-Pressure Liquid Chromatography
	Abstract	Dissolution of crystalline Ses or extraction of glassy or red amorphous selenium, prepared from aqueous Se02 by reduction, by organic solvents yields solutions containing Se6, Se7 and Ses in equilibrium as shown by HPLC. The equilibrium explains the concen-tration dependence of the molar absorbance of such solutions observed earlier. Since the Raman spectrum of red amorphous selenium does not show any lines due to See, Se7 and Ses, a rapid interconversion of selenium molecules in solution at 20 °C is postulated. Red amorphous selenium may consist of a mixture of small and medium sized ring molecules.
	Reference	Z. Naturforsch. 36b, 1085—1088 (1981); eingegangen am 23. Juni 1981
	Published	1981
	Keywords	Elemental Selenium, Equilibrium in Solution, HPLC, Amorphous Selenium
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	Identifier	ZNB-1981-36b-1085
	Volume	36

218	Author	J. Markopoulos, D. Jannakoudakis	Requires cookie*
	Title	Über die inhibierende Wirkung grenzflächenaktiver Stoffe auf die polarographische Reduktion von Cd 2+ -, Zn 2+ -und Co 2+ -Ionen in wasser-methanolischen und methanolischen Lösungen On the Inhibition Effect of Surfactants on the Polarographic Reduction of Cd 2+ , Zn 2+ and Co 2+ Ions in Aqueous Methanolic and Methanolic Solutions
	Abstract	The inhibition effect of tri-n-octylphosphine oxide (TOPO), triphenylarsine oxide (TAsO), triphenylphosphine oxide (TPO), triphenylarsine (TPAs) and triphenylphosphine (TPP) on the polarographic reduction of Cd 2+ , Zn 2+ and Co 2+ ions in aqueous methanolic and methanolic solutions has been studied.
	Reference	Z. Naturforsch. 36b, 1089—1092 (1981); eingegangen am 18. Mai 1981
	Published	1981
	Keywords	Polarography, Inhibitors, Electroreduction, Triphenylarsine Oxide
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	Identifier	ZNB-1981-36b-1089
	Volume	36

219	Author	Rüdiger Mews, Peter Kricke, Ingo Stahl	Requires cookie*
	Title	Schwefel(VI)-oxid-chlorid-imide und Schwefel(VI)-oxid-fluorid-imide [1] Sulfur(VI)-oxide-chloride-imides and Sulfur(VI)-oxide-fluoride-imides [1]
	Abstract	At room temperature in the presence of CsF sulfur-oxide-chloride-fluoride-imides RfNSOFCl (8) (Rf = CF3, C2F5, t-C3F7, C6F5) are formed from N-perfluoroalkyl-sulfinyl-imides and Cl2. At prolonged reaction times or higher temperatures the chloride is ex-changed and the difluorides RfNSOF2 are isolated in high yields. In the same way (CF3)2CFNS(0)C1CF3 (12) and (CF3)2CC1NS(0)C1CF3 (13) are obtained from (CF3)2C = N-S(0)CF3 (9) and Cl2/CsF. 12 can be fluorinated by CsF to give (CF3)2CFNS(0)FCF3 (14). 14 is also observed, when fluorine is added to 9 via XeF2 in the presence of BF3, but mainly C-S-bond cleavage occurs. SF5NS(0)FCF(CF3)2 (19) was identified by spectroscopic methods from the reaction of SFsNSOF2 and CF3CF = CF2 in the presence of CsF.
	Reference	Z. Naturforsch. 36b, 1093—1098 (1981); eingegangen am 19. Juni 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1093
	Volume	36

220	Author	Erwin Brechtel, Gerhard Cordier, Herbert Schäfer	Requires cookie*
	Title	Neue Verbindungen mit der CagMi^Big-Struktur: Zur Kenntnis von Ca^djBi^ Sr9Cd4Bi9 und Ca9Zn4Sb9 New Compounds with the CagMr^Bi» Structure: CagCcUBig, SrgCcUBig, and CagZniSbg
	Abstract	Intermetallic Phases, Crystal Structure The new compounds CagCcLjBig, SrgCcLjBig and CagZnjSbg crystallize in the ortho-rhombic system (Pbam) in the CagMrnBig structure with the following constants:
	Reference	Z. Naturforsch. 36b, 1099—1104 (1981); eingegangen am 19. Juni 1981
	Published	1981
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	Identifier	ZNB-1981-36b-1099
	Volume	36

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