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1987 (274)
81Author    Wolfgang Voelter, AdemirFarias Morel, Atta-Ur-Rahman, Muhammad Munawer, QureshiH E JRequires cookie*
 Title    Studies on the Peptide Alkaloids of Discaria febrifuga  
 Abstract    A new tryptophan-containing peptide alkaloid, "discarin-K", has been isolated from Discaria febrifuga, a shrub growing in Brazil, Argentina and Uruguay. Its structure has been determined as 1 on the basis of spectral studies. Another peptide alkaloid, franganin, was also isolated from the same plant and its 'H NMR and 13 C NMR have been studied using COSY-45, 2 D-J resolved and DEPT techniques. 
  Reference    Z. Naturforsch. 42b, 467—472 (1987); received November 28 1986 
  Published    1987 
  Keywords    Discaria febrifuga, Discarin-K, Franganin, 13 C NMR Spectra, 2D NMR Spectra 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0467.pdf 
 Identifier    ZNB-1987-42b-0467 
 Volume    42 
82Author    RichardP. Kreher, Gerald Dyker, WilhelmP. NeumannRequires cookie*
 Title    Structure and Reactivity of Isoannelated Heterocyclic Systems with Ann-and (4n+2)jr-Electrons, XII [1] 2-terr-Butyl-4-methyl-2,4-dihydropyrrolo[3,4-b]indoles: Tricyclic Hetarenes with Isoannelated Pyrrole Rings  
  Reference    Z. Naturforsch. 42b, 473—477 (1987); eingegangen am 14. November 1986 
  Published    1987 
  Keywords    Substituted 2, 3-Dihydropyrrolo[3, 4-b]indoles, Synthesis, Isolation, Spectroscopic Properties, Cycloaddition Reactions 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0473.pdf 
 Identifier    ZNB-1987-42b-0473 
 Volume    42 
83Author    Gerhard Koßmehl, Detlev BudwillRequires cookie*
 Title    Flüssig-kristalline Verbindungen aus der Thiophenreihe, Teil 4 Azomethine und Vinylene mit zentralen Azobenzol-, Stilben-und l,2-Di(2-thienyl)ethy!en-Einheiten Liquid Crystalline Compounds in the Thiophene Series, Part 4 Azomethines and Vinylenes with Central Azobenzene, Stilbene and 1,2-Di(2-thienyl)ethylene Moieties  
 Abstract    Azomethines and vinylenes, containing azobenzene, stilbene or l,2-di(2-thienyl)ethylene moieties as central groups with additional thiophene systems has been synthesized and charac-terized by their elemental analyses, IR and 'H NMR spectra and studied in relation to their liquid crystalline properties by DTA analysis and visually by their textures microscoping under polarized light. The liquid crystalline properties of these compounds and some related compounds described in literature are compared and the geometrical elements of their structures are discussed. 
  Reference    Z. Naturforsch. 42b, 478—488 (1987); eingegangen am 4. Dezember 1986 
  Published    1987 
  Keywords    Liquid Crystalline Thiophene Derivatives, Thiophene Derivatives, Azomethines, Vinylenes, Azobenzene Derivatives 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0478.pdf 
 Identifier    ZNB-1987-42b-0478 
 Volume    42 
84Author    EckehardV. Dehmlow, Roland KramerRequires cookie*
 Title      
 Abstract    The title compounds la—3c were prepared by stereoselective reduction of the respective dibromides. Pyrolysis gave allylic bromides (8, 9, 11) as primary and dienes (10, 12) as secondary products. Product ratios were independent of the stereochemistry of the starting materials. No differences of the rearrangement rates of the stereoisomers were observed in gas phase reactions of the derivatives of bicyclo[6.1.0]-and bicyclo[8.1.0]alkanes. With the larger bicyclo[10.1.0] derivatives, however, distinct differences in the thermal stability of cw-/fra«5-isomers4c/5cor 2c/3c were found in condensed phase. 
  Reference    Z. Naturforsch. 42b, 489—494 (1987); received September 24 1986 
  Published    1987 
  Keywords    Dibromocarbene Adducts, Stereoselective Debromination, Rearrangement, Allylic Bromides 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0489.pdf 
 Identifier    ZNB-1987-42b-0489 
 Volume    42 
85Author    Nien Man, Clemens Schuchmann, Von SonntagRequires cookie*
 Title    Hydroxy! Radical-Induced Oxidation of Diisopropyl Ether in Oxygenated Aqueous Solution. A Product and Pulse Radiolysis Study  
 Abstract    In the radiolysis of N 2 0/0 2 (4:1)-saturated aqueous solutions of diisopropyl ether(10~ 3 mol dm ~ 3), OH radicals abstract H-atoms, thereby producing radicals at C(2) (1 = 78%) and to a lesser extent at C(l) (2 — 22%) which are converted by oxygen into the corresponding peroxyl radicals 3 and 4. Some 0 2 radicals are formed by the reaction of radiolytically produced H atoms with oxygen. Methyl radicals formed in the course of the bimolecular decay of 3 and 4 give rise to methylperoxyl radicals 5. At high dose rate as delivered by 2.8 MeV electron pulses the products (G values in parentheses) are: isopropyl acetate (2.6), acetone (1.1), isopropanol (1.1), 2-iso-propoxypropanal (1.4, estimated), formaldehyde (2.0), organic hydroperoxides (0.4), organic acids (0.5) and hydrogen peroxide (1.9). At low dose rates (<0.39 Gy s -1) G(acetone) is consid-erably increased and is no longer balanced by an equivalent yield of isopropanol. This is thought to be due to an intramolecular H-abstraction of radical 3. Pulse radiolysis studies revealed that 3, 4 and 5 decay by second order kinetics. At the early stages the bimolecular decay is faster (2k = 6 x 10 7 dm 3 moP's" 1) than toward the end (2k = 2 x 10 7 dm 3 mor I s" 1). It is suggested that the faster decay at the beginning is due to a preponderance of termination by the primary peroxyl radical 4 with the tertiary peroxyl radical 3 while at later stages termination is mainly governed by the reaction of 3-1-3 which produces 5. The rate constants k(5 + 3) and k(5 + 5) are very likely much higher than 2k(3 + 3), hence 2k(3 + 3)<2 x 10 7 dm 3 moP's" 1 . In 0 2 -saturated solutions 0 2 plays a considerable role in the termination reactions, and organic hydroperoxides which are unimportant in N 2 0/0 2 -saturated solutions at high dose rates are now the major products. 
  Reference    Z. Naturforsch. 42b, 495—502 (1987); received November 7 1986 
  Published    1987 
  Keywords    Diisopropyl Ether, Hydroxyl Radicals, Peroxyl Radicals, Pulse Radiolysis 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0495.pdf 
 Identifier    ZNB-1987-42b-0495 
 Volume    42 
86Author    Hans Möhrle, Heinz DwuletzkiRequires cookie*
 Title    Acylation Reactions of Enamines  
 Abstract    The ratio of isomeric enaminones, obtained by acylation of enamines with acid chlorides in the presence of triethylamine, depends on the possibility of forming isomeric enoles of the inter-mediate cyclobutanone adducts. 
  Reference    Z. Naturforsch. 42b, 503—506 (1987); eingegangen am 30. Oktober 1986 
  Published    1987 
  Keywords    Enamines, Enaminones, 1, 4, 5, 6-Tetrahydropyridines 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0503.pdf 
 Identifier    ZNB-1987-42b-0503 
 Volume    42 
87Author    Guido Wenski, Albrecht MewisRequires cookie*
 Title    Ternäre Varianten des Pyrit-Typs: Darstellung und Struktur von SrPt 4 P 6 , SrPt 4 As 6 , BaPt 4 As 6 und BaPt 2 P 3 Ternary Pyrite-Type Derivatives: Preparation and Crystal Structure of SrPt 4 P 6 , SrPt 4 As 6 , BaPt 4 As 6 and BaPt 2 P 3  
 Abstract    The isotypic compounds SrPt 4 P 6 , SrPt 4 As 6 and BaPt 4 As 6 were found to crystallize with a Pyrite-type derivative structure (monoclinic, C2/c, Z = 4) in which one Sr or Ba atom per formula unit occupies the position of a P 2 or As 2 pair. BaPt 2 P 3 forms another Pyrite-type related structure (monoclinic, I > 2 1 /c, Z = 4) built up by Ba 2 Pt and Pt 3 P 6 layers. All crystal structures were refined from four-circle diffractometer data, the lattice constants are: 
  Reference    Z. Naturforsch. 42b, 507—513 (1987); eingegangen am 28. Oktober 1986 
  Published    1987 
  Keywords    Ternary Pyrite-Type Derivatives, Platinum, Crystal Structure 
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 Identifier    ZNB-1987-42b-0507 
 Volume    42 
88Author    Abdul Malik, Zaheer Ahmed, Najam-Ul-Hussain Kazmi, Abdul Qasim, KhanH E JRequires cookie*
 Title    Efficient Syntheses of a New Class of 6-Amino-6-deoxy Sugars  
 Abstract    Amino Sugars, Triflate Displacement, Amino Acids Novel one step syntheses of a new class of phar-macologically interesting 6-amino-6-deoxy sugars are described. The reaction sequence consists of esterifying 1,2:3,4-di-O-isopropylidene-a-D-galac-topyranose with trifluoromethanesulfonic anhydride and reacting the resulting triflate with a variety of suitably protected naturally occurring amino acids. The difficulties which, sometime, are encountered during displacement reactions in carbohydrates are absent. 
  Reference    Z. Naturforsch. 42b, 514—515 (1987); received October 29 1986 
  Published    1987 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0514_n.pdf 
 Identifier    ZNB-1987-42b-0514_n 
 Volume    42 
89Author    R. Steudel, D. Jensen, B. Plinke, Z. NaturforschRequires cookie*
 Title      
 Abstract    Auf Seite 164, linker Absatz, wurden beim Druck 2 Zeilen vertauscht. Der Absatz soll heißen: able concentration can be deduced from the forma-tion of SC1 4 on cooling shown by the low temperature Raman spectrum of the same sample illustrated in Fig. lb. The strong lines of SC1 4 at 277, 449 and 468 cm -1 [5] can thus be used to detect and deter-mine even small amounts of chlorine in dichloro-sulfane. 
  Reference    Z. Naturforsch. 42b, 517 (1987) 
  Published    1987 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0517_e.pdf 
 Identifier    ZNB-1987-42b-0517_e 
 Volume    42 
90Author    Michael Witt, HerbertW. Roesky, Mathias Noltemeyer, GeorgeM. SheldrickRequires cookie*
 Title    Synthese und Struktur von H 2 NS0 2 NWC1 4 - ein Kirsanov-Reagens mit einem Übergangsmetallatom Synthesis and Structure of H 2 NS0 2 NWC1 4 - a Kirsanov Reagent with a Transition Metal Atom  
 Abstract    H 2 N-S0 2 -NWC1 4 (1) has been synthesized from WC1 6 and S0 2 (NH 2) 2 , and forms adducts with donor solvents such as pyridine and acetonitrile. 1CH 3 CN crystallizes in the space group P2,/n with cell constants a = 652.5(1); b = 2325.3(2); c = 775.8(1) pm; ß = 90.32(1)°. The nitrogen-tungsten bond length of 173.0 pm and the S—N—W bond angle of 169.3° indicate a W=N double bond. 
  Reference    Z. Naturforsch. 42b, 519—521 (1987); eingegangen am 1. Dezember 1986/20. Januar 1987 
  Published    1987 
  Keywords    Crystal Structure, Sulfamide, Nitrogen-Tungsten Double Bond 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0519.pdf 
 Identifier    ZNB-1987-42b-0519 
 Volume    42 
91Author    PeterG. Jones, Ralf Schelbach, Einhard SchwarzmannRequires cookie*
 Title    Hydroxy Complexes of Gold 2. Calcium Aurates [1]  
 Abstract    Two calcium aurate phases have been obtained as single crystals, phase 1 from H AUC1 4 + Ca(OH) 2 and phase 2 from NaAu(OH) 4 + Ca(C10 4) 2 . An X-ray structure determination of 1 shows its composition to be Ca 2 (0H) 3 (H 2 0) 4 [Au(0H) 4 ]. The apparent space group is Cmcm, but this corresponds to a sub-cell of the true structure. The disordered Cmcm structure was refined to R 0.032 for 813 reflections. The coordination geometry is square planar at gold (Au-O 1.97, 1.99 Ä), cubic at Ca(l) and octahedral at Ca(2). Phase 2 crystallizes in a primitive tetragonal cell with a 6.94, c 7.71 Ä; it is probably Ca[Au(OH) 4 ] 2 , but this has not yet been confirmed by a full structure determination. 
  Reference    Z. Naturforsch. 42b, 522—524 (1987); received December 2 1986 
  Published    1987 
  Keywords    Gold(III), Hydroxide, Calcium, Crystal Structure 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0522.pdf 
 Identifier    ZNB-1987-42b-0522 
 Volume    42 
92Author    M. Veith, A. BeloRequires cookie*
 Title    Stickstoffverbindungen von Elementen der dritten Hauptgruppe mit intra-und intermolekularen Donor-Akzeptor-Bindungen, III [1]. Dynamische Phänomene und Lewis-Säure-Stärke Nitrogen Compounds of Elements of the Third Main Group with Intra-and Intermolecular Donor Acceptor Bonds, III [1]. Dynamic Phenomena and Lewis Acidity  
 Abstract    Compounds of the general formula f BuN(H)-SiMe 2 -N(r Bu)ElX 2 (El = B, X = Me (lm), F (If), Cl (lc); El = AI, X = Me (2m), Cl (2c), Br (2b); El -Ga, X -Me (3m), Cl (3c), Br (3b); El -In, X -Me (4m), Cl (4c), Br (4b); El -Tl, X -Me (5m)) and r BuN(D)-SiMe 2 -N(r Bu)ElMe 2 (El = Al (2d), Ga (3d), In (4d)) have been characterized by IR and temperature dependent ! H NMR techniques with respect to their structural changes in solution. A reversible, dynamic, intramolecular equilibrium between two enantiomeric four-membered rings has been established to be responsible for the changes in the spectra. The cyclic form Bl, which arises from Lewis acid base interaction of the rerr-butyl-amino with the E1X 2 group, transforms to the mirror-image B2 via an acyclic intermediate, in which reorien-tation of the groups by rotation or inversion can take place. In the boron derivatives (lm, lc, and If) no comparable N—B interaction can be detected. The Lewis acidity of the E1X 2 group deduced from NH wave numbers increases within the following series: TlMe 2 <GaMe 2 ~InMe 2 <AlMe 2 <GaBr 2 =InBr 2 <GaCl 2 ~AlBr 2 ~InCl 2 <AlCl 2 . Intramolecular hydrogen transfer from one nitrogen atom to the other can be excluded by comparison of the rate constant k H vs. k D . The free enthalpy of activation A G* depends on the acidity of E1X 2 , the steric requirements and the relative masses of X. The syntheses and characterisation of If, 2b, 3b, 4b, 2d, 3d, and 4d are described. 
  Reference    Z. Naturforsch. 42b, 525—535 (1987); eingegangen am 6. November 1986 
  Published    1987 
  Keywords    Temperature Dependent NMR, Synthesis, Intramolecular Rearrangements, Donor Acceptor Bonds 
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 Identifier    ZNB-1987-42b-0525 
 Volume    42 
93Author    R. Burnus, J. Köhler, A. SimonRequires cookie*
 Title    Preparation of Single Crystals and Structure Refinement  
 Abstract    Reduced Niobate, Cluster, Preparation. Structure Dark green single crystals of Mg 3 Nb 6 O u have been prepared by heating a pellet containing MgO, Nb, Nb 2 0 5 (15:14:8) at 1550 °C in a Nb-container. Single crystals of the isotypic Mn 3 Nb 6 On were formed by heating a mixture of LiF, MnF 2 , Mn, NbO, Nb0 2 (1:1:1:1:2) in a corundum crucible at 750 °C. Both compounds crystallize in the trigonal space group P3 ml (Z = 1) with a = 6.041(1), c = 7.466(1) and a = 6.080(1), c = 7.627(1), respectively. The positional parameters for Mg 3 Nb 6 O n are in excellent agreement with those determined by Marinder from powder data. 
  Reference    Z. Naturforsch. 42b, 536—538 (1987); eingegangen am 23. Dezember 1986 
  Published    1987 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0536.pdf 
 Identifier    ZNB-1987-42b-0536 
 Volume    42 
94Author    Stanislav Heřmánek, Jiří Fusek, Otomar Kříž, Bohuslav Čásenský, Zbynĕk ČernýRequires cookie*
 Title    Alkoxohydridoaluminates. I 27 AI NMR Characteristics of (C 4 H9) 4 N + AlH4_"(OR)"" in Benzene  
 Abstract    The 27 A1 NMR spectra of (C 4 H 9) 4 N + AlH 4 _ n (OR)"-prepared in the reaction of (C 4 H 9) 4 NA1H 4 with ROH (R -CH 3 , C 2 H 5 , /-C 3 H 7 , r-C 4 H 9 , «-C 5 H U , n-C 9 H 19 , cyclo-C 6 U n , C 6 H 5 , CH 3 OCH 2 CH 2) in benzene show — in contrast to the Li + and Na + salts — a distinct H-splitting, which has allowed to ascertain: 1) the presence of all members (n = 0—4) in solution, 2) the Al chemical shift and AI —H coupling constant of all individual classes, namely (n = 0): 101.6 ppm, quintet 174 Hz; (n = 1): 114-123 ppm, quartet 184-193 Hz; (n = 2): 103-112 ppm, triplet 197-219 Hz; (n = 3): 75-91 ppm, doublet 218-237 Hz; (n = 4): 51-73 ppm, singlet, 3) in-creased shielding in the order: CH 3 < n-R = i-R = sec-R < C 6 H U C 6 H 5 < r-C 4 H 9 . The anomalous "sagging" pattern of the curve: d 27 Al vs. number of OR groups, is interpreted on the basis of significant differences among Al and H and OR in electronegativity. 
  Reference    Z. Naturforsch. 42b, 539—545 (1987); received October 1 1986 
  Published    1987 
  Keywords    Tetrahydridoaluminates, Alkoxohydridoaluminates, Tetraalkoxoaluminates, 27 A1 NMR Spectra 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0539.pdf 
 Identifier    ZNB-1987-42b-0539 
 Volume    42 
95Author    Wolfgang Hönle, Arndt Simon, Gabriele GerlachRequires cookie*
 Title    Darstellung, Kristallstruktur und Eigenschaften von ß-Ga 2 Br 4 Preparation, Crystal Structure and Properties of y3-Ga 2 Br 4  
 Abstract    The compounds Ga 2 Br 4 (a+ß) have been prepared by reacting GaBr 3 with Ga metal without a solvent or in a hydrocarbon medium. a-Ga 2 Br 4 is isotypic with Ga 2 Cl 4 , and /3-Ga 2 Br 4 with Ga 2 I 4 . Both forms have to be formulated as Ga + (GaBr 4)~ according to their crystal structures. The first order phase transition a—*ß has been investigated by means of DTA and temperature dependent X-ray powder photographs. The crystal structure of /3-Ga 2 Br 4 has been refined with single crystal data (R3c; a = 2163.4(8) pm; c = 869.2(4) pm; Z = 18; R = 0.037). Main building units are GaBr 4 " tetrahedra (d(Ga —Br) = 232.9 pm), connected in three dimensions by capped trigonal prisms (6+2+1) around Ga + . The crystal chemical relationships between y3-Ga 2 Br 4 and Ga 2 I 4 are discussed. 
  Reference    Z. Naturforsch. 42b, 546 (1987); eingegangen am 13. November 1986 
  Published    1987 
  Keywords    Phase Transition, DTA Investigation, Crystal Structure 
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 Identifier    ZNB-1987-42b-0546 
 Volume    42 
96Author    H. Schmidbaur, R. Nowak, W. Bublak, P. Burkert, B. Huber, G. MüllerRequires cookie*
 Title    Strukturbestimmung von Ga[GaCl 4 ] und a-Ga[GaBr 4 ] nach Kristallisation aus Halogenbenzolen Structure Determination of Ga[GaCl 4 ] and a-Ga[GaBr 4 ] Crystallized from Halobenzene Solvents  
 Abstract    Gallium(I) Tetrahalogenogallates(III), Crystal Structure, Gallium(I) Arene Coordination, 69 Ga NMR Spectra Single crystals of Ga[GaCl 4 ] and a-Ga[GaBr 4 ] have been obtained by crystallization from chlorobenzene and bromobenzene, respectively. The crystal structures of the two compounds, determined previously only on the basis of photographic data, were refined to a more satisfactory level of accuracy. The results confirm the presence of tetrahedral GaX 4 ~ anions as thecounterions to dodecahedrally coordinated Ga + cations. The gallium-halogen distances in these dodecahedral arrays fall into four classes, thus resulting in a significant asymmetry of the Ga(I) center. This deviation from ideal S 4 symmetry is also apparent in the 69 Ga NMR spectra of the crystalline powder samples. Approximate calculation of the data leads to asymmetry parameters (rj) of 0.44 and 0.27 for the chloride and bromide, respectively. Crystal data Ga[GaCl 4 ]: Pnna (#52), a -7.200(1), b = 9.625(1), c = 9.498(1) Ä; Z = 4. For a-Ga[GaBr 4 ]: Pnna, a = 7.528(1), b = 9.972(1), c = 10.010(1) Ä, Z -4. 
  Reference    Z. Naturforsch. 42b, 553—556 (1987); eingegangen am 9. Dezember 1986 
  Published    1987 
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 Identifier    ZNB-1987-42b-0553 
 Volume    42 
97Author    Reinhard Nesper, Jan CurdaRequires cookie*
 Title    das erste Chalcogenid mit zweiwertigem Aluminium Al 7 Te 10 — the First Chalcogenide of Divalent Aluminum  
 Abstract    Al 7 Te 10 is prepared from a melt of the elements in stoichiometric amounts in a corundum crucible contained in a sealed quartz ampoule. The ruby red cube shaped crystals are stable below 840 K. The structure of Al 7 Te, 0 (R32-D^; a = 1439.5 pm, c = 1793.2 pm, Z = 6, R = 0.03) is a distorted defect variant of a tetrahedral arrangement of the 4H-polytype. The central unit, a double barrelane [Te 4 Al 4 —Al 4 Te 4 ], contains an Al —Al bond of 260 pm, which is somewhat longer (n = 0.83) than an expected single bond (250 pm, n = 1). This homopolar bond disturbs the electrostatically favorable (Al—Te—)" sequence in the structure which is compensated by the occurrence of four-membered Al 2 Te 2 rings. Al 7 Te 10 is a Zintl phase according to l/2{[Al 2+ -Al 2+ ][Al 3+ ] !2 [Te 2 ~] 20 } and exhibits semiconducting and diamagnetic behaviour. 
  Reference    Z. Naturforsch. 42b, 557 (1987); eingegangen am 9. Dezember 1986 
  Published    1987 
  Keywords    Synthesis, Crystal Structure, Divalent Aluminum, Aluminum-Aluminum Bonds 
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 Identifier    ZNB-1987-42b-0557 
 Volume    42 
98Author    Henry Strasdeit, Bernt Krebs, G. HenkelRequires cookie*
 Title    [Fe 6 Se 9 (SR) 2 ] 4 ' Clusters (R = Me, CH 2 Ph): Synthesis and Characterization, and the X-Ray Structure of (PhCH 2 NEt3)4[Fe 6 Se 9 (SMe)2]  
 Abstract    The compounds (PhCH 2 NEt 3) 4 [Fe 6 Se 9 (SMe) 2 ] (1) and (Et 4 N) 4 [Fe 6 Se 9 (SCH 2 Ph) 2 ] (2) have been isolated in good yields from Fe(SR) 3 (R = Me, CH 2 Ph)/"Na 2 Se 2 " reaction mixtures in methanol/N,N-dimethylformamide after addition of the appropriate tetraalkylammonium chlorides. 1 is monoclinic, space group P2]/c, Z = 4, with a = 18.697(14), b -22.606(16), c = 15.989(11) Ä, and/3 = 94.15(6)° at 140 K. Its structure has been refined to R (R w) -0.092 (0.075). The [Fe 6 Se 9 (SMe) 2 ] 4_ anion contains six coplanar iron atoms which are present in distorted tetrahedral Se 4 and Se 3 (SMe) ligand surroundings. The Se atoms are n, and fi 4 bridging. The four central Fe atoms and the Se atoms constitute a Fe 4 Se 9 group that is structurally related to 4[Fe 2 Se 3 ] 2_ double tetrahedral chains and 2 [FeSe] layers. The Fe atoms in the [Fe 6 Se 9 (SMe) 2 ] 4 ~ cluster are antiferromagnetically coupled. 1 has a room-temperature magnetic moment of 1.22 ,M B /Fe. Cyclic voltammograms, and electronic, infrared, and proton resonance spectra of 1 and 2 have been measured. 
  Reference    Z. Naturforsch. 42b, 565—572 (1987); received December 1 1986 
  Published    1987 
  Keywords    Hexanuclear Fe/Se/SR Complexes, Synthesis, X-Ray, Magnetic and Electrochemical Properties 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0565.pdf 
 Identifier    ZNB-1987-42b-0565 
 Volume    42 
99Author    Hidenari Inoue, Takashi Nakagome, Takeshi Kuroiwa, Tsuneo Shirai, Ekkehard FluckRequires cookie*
 Title    Infrared, 57 Fe Mössbauer, and 31 P NMR Spectroscopic Characterization of Fe(CO) 4 L (L = Phosphine and Phosphite)  
 Abstract    A series of trigonal bipyramidal Fe(CO) 4 L complexes has been prepared and characterized by infrared, 57 Fe Mössbauer and 31 P NMR spectroscopy. A linear correlation, with a negative slope, between the CO stretching frequencies and the isomer shifts demonstrates that the triple bond nature of the carbonyl ligands is strengthened with increasing iron-to-phosphorus back donation. The linear dependence of the quadrupole splittings on the isomer shifts with a positive slope has revealed that the cr-donor capability of the phosphine or phosphite ligand is offset by the ^ • -acceptor capability. The formation of Fe(CO) 4 L complexes from the corresponding free ligands is accompanied by a downfield shift of 31 P NMR chemical shifts. The coordination shifts are linearly correlated with the Mössbauer isomer shifts. 
  Reference    Z. Naturforsch. 42b, 573—578 (1987); eingegangen am 8. Januar 1987 
  Published    1987 
  Keywords    Phosphinetetracarbonyliron, Phosphitetetracarbonyliron, IR Spectra, 31 P NMR Spectra, 57 Fe Mössbauer Spectra 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0573.pdf 
 Identifier    ZNB-1987-42b-0573 
 Volume    42 
100Author    GerdU. Spiegel, Othmar StelzerRequires cookie*
 Title    PH-funktionelle Phosphane mit a-und ^-ständigen 2-Pyridylsubstituenten 2-C5H4N—[CH  
 Abstract    2 ]"—PRH (R = H, /Pr, fBu, Ph, 2-C 5 H 4 N-[CH 2 ]"; n = 1, 2) PH-Functional Phosphanes with 2-Pyridyl Substituents in a-or ß-Position 2-C5H4N —[CH 2 ]"—PRH (R = H, /Pr, rBu, Ph, 2-C 5 H 4 N-[CH 2 ]"; n = 1,2) PH-functional phosphanes containing a 2-pyridyl substituent in a-or /3-position to phosphorus, e.g. 2-C 5 H 4 N — [CH 2 ]"—PRH (R = H, /Pr, *Bu, Ph; « = 1,2) have been obtained. The reactivity of the PH-groups can be employed for the synthesis of tridentate NPN-hvbrid donors. [2-C5H4N —CH 2 —CH 2 ] 2 PR (R = H. Ph). The phosphanes 2-C 5 H 4 N-[CH 2 ]"-PRH behave as monodentate ligands in transition metal complexes and form labile chelate ring systems. They may bridge metal-metal bonds to form seven membered ring systems, e.g. Mo 2 PC 3 N. The coordi-nation of the N-donor of the ligands 2-C 5 H 4 N — [CH,]"-PRH to a transition metal atom is indi-cated by a lowfield shift and a small 3I P-13 C-splitting of the l3 C{ ! H} NMR signal of carbon atom 6 in the pyridin ring system. 
  Reference    Z. Naturforsch. 42b, 579—588 (1987); eingegangen am 4. August 1986 
  Published    1987 
  Keywords    2-Pyridyl Substituent, Reactions at PH-Functions, Chelate Complexes, Ligand Replacement, I3 C{'H} NMR Spectra 
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 Identifier    ZNB-1987-42b-0579 
 Volume    42 
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