Go toArchive
Browse byFacets
Bookbag ( 0 )
'Nitrogen' in keywords
Results  5 Items
Sorted by   
Section
Publication Year
2001 (2)
1987 (1)
1983 (1)
1976 (1)
1Author    H. Erbert, W. Roesky, Nasreddine Benm, Oham Ed, Klaus Keller, Nayla Keweloh, M. Athias, N. Oltem Eyer, GeorgeM. SheldrickRequires cookie*
 Title    Synthesis and Crystal Structure of Seven-M em bered Sulfur Nitrogen Rings Containing Carbon  
 Abstract    The reaction of C1SCF2CF2SC1 and (Me3SiN)2SR2 proceeds with formation of the seven-mem-bered ring compounds 4a, R = CH3, and 4b, R = C2H 5. 4a was shown by an X-ray structure determination to contain a non-planar ring system. 
  Reference    Z. Naturforsch. 42b, 1249—1252 (1987); eingegangen am 5. Mai 1987 
  Published    1987 
  Keywords    Crystal Structure, Sulfur, Nitrogen 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-1249.pdf 
 Identifier    ZNB-1987-42b-1249 
 Volume    42 
2Author    JohnG. Palmer, PaulA. Doemeny, GerhardN. SchrauzerRequires cookie*
 Title    The Chemical Evolution of a Nitrogenase Model, XXIII. The Nature of the Active Site and the Role of Homocitric Acid in MoFe-Nitrogenase  
 Abstract    The iron-molybdenum cofactor (FeMo-co) of bacterial nitrogenase is a heterometallic cluster of composition MoFe7S9 that is attached to the apoprotein by a coordinative Mo-N bond to the imidazole group of hisa442, and by a Fe-S bond to cysa.215. The molybdenum atom of FeMo-co in the enzyme in addition is coordinated to one molecule of homocitrate (he), which is required for maximal N2 reducing activity. The molybdenum atom in the enzyme-bound FeMo-co thus is hexacoordinated and cannot react with substrates unless free coordination sites are made available. It is proposed that the reactions of the substrates o f nitrogenase occur at a molybdenum active site consisting of a mononuclear molybdenum homocitrate complex attached to hisaAA2 of the apoprotein that in the functional enzyme is generated from FeMo-co by a reversible, redox-linked dissociation of the Fe7S9-c;y5' cluster. Studies with catalytic model systems consisting of complexes of molybdenum with imidazole and hydroxo-carboxylate ligands support this proposal and provide a rationale for the specific activating effect of homocitrate in nitrogenase. 
  Reference    Z. Naturforsch. 56b, 386—393 (2001); received January 17 2001 
  Published    2001 
  Keywords    Nitrogen, Acetylene, Homocitric Acid 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-0386.pdf 
 Identifier    ZNB-2001-56b-0386 
 Volume    56 
3Author    MarcoH. Klingele, Gunther Steinfeld, Berthold KerstingRequires cookie*
 Title    Synthesis and Coordination Chemistry of Novel Binucleating Macrocyclic Ligands with Amine-thioether and Amine-thiophenolate Donor Functions  
 Abstract    The ability of the aromatic tetraaldehyde l,2-bis(4-rm-butyl-2,6-diformylphenylsulfanyl)-ethane (1) to function as a precursor in the preparation of binucleating hexaamine-dithiolate lig­ ands has been investigated. Reductive amination of compound 1 with bis(aminoethyl)amine un­ der medium-dilution conditions affords the macrobicyclic hexaamine-dithioether compound L 1. Deprotection of the [1+2] condensation product gives the corresponding 24-membered hexa-amine-dithiophenol ligand H2L2. The formulation of L 1 as a macrobicyclic amine-thioether was confirmed by an X-ray crystal structure determination of the tetranuclear nickel(II) complex of L 1, [{ (L jN iiC lili^ -C l^K B P h ;) (2b). The formulation of the doubly deprotonated form (L2)2-of H2L2 as a 24-membered amine-thiophenolate ligand was confirmed by an X-ray crystal structure determination of the dinuclear cobalt(III) complex, [(L2)Com(^-OH)](C1 0 4) 2 • Cl (3). The preparation and the crystal structures of the new compounds are described. 
  Reference    Z. Naturforsch. 56b, 901—907 (2001); received June 5 2001 
  Published    2001 
  Keywords    Macrocyclic Ligands, Nitrogen, Sulfur 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-0901.pdf 
 Identifier    ZNB-2001-56b-0901 
 Volume    56 
4Author    HerbertW. Roesky, Pierre Schäfer, Mathias Noltemeyer, GeorgeM. SheldrickRequires cookie*
 Title    Zur Darstellung und Struktur des 1.3-Dichloro-5-N.N-dimethylamino-1.3-dithia-2.4.6-triazins Synthesis and Structure of l,3-Dichloro-5-N,N-dimethylamino-l,3-dithia-2,4,6-triazine  
 Abstract    The six membered ring of composition (CH3)2NCN3S2Cl2 8 a was prepared from N,N-dimethylguanidinhydrochloride and trithiadiazindichloride. 3 a was characterized on the basis of mass, 1 H, 13 C NMR spectra and X-ray structure analysis. Crystals of 3 a are monoclinic, space group P2i/c, with a — 660.3(6), b = 834.5(7), c = 1774.7(15) pm, ß = 112.83(6)° and Z = 4. The C2N unit lies approximately in the plane of the [-CNSNSN-] ring, with both Cl atoms on the same side of the ring. 
  Reference    Z. Naturforsch. 38b, 347—349 (1983); eingegangen am 16. September 1982 
  Published    1983 
  Keywords    Six Membered Ring, Carbon, Sulfur, Nitrogen, X-Ray Structure 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-0347.pdf 
 Identifier    ZNB-1983-38b-0347 
 Volume    38 
5Author    Susanne Elbel, HeindirkTom DieckRequires cookie*
 Title    Photoelektronenspektren von Verbindungen der V. Hauptgruppe, III 1 Methylhalogenverbindungen MeEHal2 und Me2EHal Photoelectron Spectra of Group V Compounds, III 1 Methylhalogen Compounds MeEHal2 and Me2EHal  
 Abstract    The He I photoelectron spectra of certain MeEHal2 and MeaEHal compounds (E = (N), P, As, Sb; Hal = (F), Cl, Br, J; Me = CH3) are interpreted in terms of a "composite molecule" approach derived for C3v/Cs systems. Although an "internal standard" is missing here, substituent group-orbitals (njjai, C-H) may be classified with respect to their orien-tations in space (R, V, T). Ionisation energies are assigned according to this assumption. PE data of the isoelectronic EMe3/EHal3 compounds and of related molecules (Me2EH, MePH2, CF3PBr2) as well as EHMO calculations with partial inclusion of spin orbit coupling are used to confirm the assignments given for Me2EHal/MeEHal2 series. Correlations between PE ionisation energies (e.g. nE (IE)) and molecular or atomic properties are critically revised and discussed. 
  Reference    (Z. Naturforsch. 31b, 178—189 [1976]; eingegangen am 1. September 1975) 
  Published    1976 
  Keywords    Photoelectron Spectra, Nitrogen, Phosphorus, Antimony Methyl Halides, n-Ionizations 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/31/ZNB-1976-31b-0178.pdf 
 Identifier    ZNB-1976-31b-0178 
 Volume    31