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'Stereochemistry' in keywords Facet   Publication Year 1983  [X]
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1Author    Annegret LipkaRequires cookie*
 Title    Darstellung und Kristallstruktur des 2:3-Adduktes von Antimontrichlorid und 4-Phenylpyridin, 2 SbCl3 * 3 (CnH9N) Preparation and Crystal Structure of the 2:3 Adduct of Antimony Trichloride and 4-Phenylpyridine, 2SbCl3 * 3(CnH9N)  
 Abstract    A congruently melting phase of molar ratio 2:3 was identified in the system SbCl3/4-phenylpyridine. The structure consists of two different types of complex units: One SbCl3 molecule is bonded to one 4-phenylpyridine ligand only, whereas the other one forms a complex with two 4-phenylpyridine ligands. The SbCl3 unit in the 1:1 species is pyrami-dally shaped, whereas the SbCl3 unit in the 1:2 species displays a T-shaped geometry. The mean angle between the phenyl and pyridyl planes is 33.3°; mean bond lengths are <Sb-Cl> = 247.6 pm and <Sb-N> = 241.7 pm. 
  Reference    Z. Naturforsch. 38b, 341—346 (1983); eingegangen am 27. September 1982 
  Published    1983 
  Keywords    Antimony Trichloride, Crystal Structure, Stereochemistry 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-0341.pdf 
 Identifier    ZNB-1983-38b-0341 
 Volume    38 
2Author    Walter Tötsch, Fritz SladkyRequires cookie*
 Title    The Hydrolysis of TeF6  
 Abstract    The stereochemistry of the hydrolysis of tellurium hexafluoride has been followed up by 125 Te NMR spectroscopy for each individual step of replacement of fluorine by a hydroxy group. 
  Reference    Z. Naturforsch. 38b, 1025—1026 (1983); eingegangen am 18. März 1983 
  Published    1983 
  Keywords    Tellurium Hexafluoride, Hydrolysis, Stereochemistry, 125 Te NMR Spectra 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1025_n.pdf 
 Identifier    ZNB-1983-38b-1025_n 
 Volume    38 
3Author    KurtH. Pilgram, LairdH. Gale, GlennE. PollardRequires cookie*
 Title    a-hydroxyphostones  
 Abstract    The addition-cyclocondensation reactions of three /?-hydroxyketones with four dialkyl phosphites gave 2-alkoxy-3-hydroxy-l,2-oxaphospholane-2-oxides ("a-hydroxyphosto-nes") (7), in moderate yields. In the solid state and in solution, these compounds exist as dimers with hydrogen bonding between the hydroxyl group and the phosphoryl oxygen atom of an adjacent molecule. The crystal and molecular structure of 3-hydroxy-2-methoxy-3,5,5-trimethyl-l,2-oxaphospholane-2-oxide (7 a) has been determined by single-crystal X-ray crystallography: C7H15O4P, monoclinic space group P2-l/n, cell dimensions a = 8.087(1) Ä, b = 13.386(2) A, c = 9.306(1) A, V = 1007.4 Ä 3 , Z = 4, final R = 0.052. The five-membered ring is puckered, with the carbon bearing the OH and CH3 groups lying out of the plane of the remaining four atoms in the ring. The doubly bonded oxygen attached to the phosphorus atom and the hydroxyl oxygen are in a cis-relationship. The 0(l)-0(4) intermolecular bond distance of 2.75 Ä suggests hydrogen bonding. The 0(1)-H(1) intermolecular bond distance of 1.97 Ä is consistent with this conclusion. Thorough synthetic studies have been carried out on intramolecular esters of 3-hydroxyalkane (and alkene) phosphonic and phosphinic acids (phosto-nes [1]). For example, dehydration of 3-hydroxy-alkanephosphonic acids gave phostones of general structure 1 [2] (Table I). Similar phostones, 2 and 3, were obtained from the reactions of 1,3-dihalo-alkanes with phosphonites and phosphinites, re-spectively [3]. At elevated temperature, 3-bromo-alkanephosphonates are converted into phostones 4 [4]. Acyl-lactone rearrangement of a-acetyl-a-diethoxyphosphonylbutyrolactone gave 5 [5]. Unsaturated phostones (8) are obtained by dehydration of the corresponding (3-hydroxy-3-phenyl-prop-2-enyl)phosphonic acids [6]. 3-Hy-droxypropenylphosphonates, prepared by catalytic reduction of 3-hydroxy-l-propynyl-phosphonates, cyclocondense to 9 having potent Cholinesterase inhibitory activity [7]. The reaction of dialkyl 1,2-alkadienylphosphonates with halogens [8-10] and sulfenyl chlorides [12] gave 10. In the reaction of 3-methyl-l,2-butadienephos-phonyl di chloride with halogens, unsaturated tetra-halophostones (11), are formed [13]. The chlorina-tion of 2-methyl-2,3,5-hexatriene-4-phosphonyl di-chloride proceeds similarly in the direction of cyclo-dechlorination to form 12 [14]. 
  Reference    Z. Naturforsch. 38b, 1122—1129 (1983); received May 6 1983 
  Published    1983 
  Keywords    X-Ray, Stereochemistry, Hydrogen Bonding, Dimerization 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1122.pdf 
 Identifier    ZNB-1983-38b-1122 
 Volume    38