| | 2 | Author
| Joachim Fuchs, Axel Thiele, Rosemarie Palm | Requires cookie* | | | Title
| Strukturen und Schwingungsspektren des Tetramethylammonium -a -dodekawolframatosilikats und des Tetrabutylammonium-/?-dodekawolframatosilikats Structures and Vibrational Spectra of Tetramethylammonium a-Dodecatungstosilicate and Tetrabutylammonium /?-Dodecatungstosilicate  | | | | Abstract
| Dodecatungstosilicates free of crystal water were prepared for the first time by using tetraalkylammonium as cation. The crystal structure of the tetramethylammonium a-dodeeatungstosilicate [N(CH3)4]4SiWi2C>4o (1) and tetrabutylammonium)S-dodecatungs-tosilicate, [N(C4H9)4]4SiWi204o (2) were solved by X-ray diffraction. (1) crystallizes tetragonal in the space group 14 with lattice parameters a = 14.642 A; c= 12.706 A; (2) orthorhombic, space group P2i2x2i with a = 29.277 A, b = 22.181 A and c = 15.381 A. The differences between the two isomeric heteropolyanions are discussed, especially the distances and angles between the tungsten atoms. Comparison of characteristic differences in the vibrational spectra permits the identifica-tion of the isomeric anions. | | | |
Reference
| Z. Naturforsch. 36b, 161—171 (1981); eingegangen am 22. Oktober 1980 | | | |
Published
| 1981 | | | |
Keywords
| Dodecatungstosilicates, Isomers, X-ray, Vibrational Spectra | | | |
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| default:Reihe_B/36/ZNB-1981-36b-0161.pdf | | | | Identifier
| ZNB-1981-36b-0161 | | | | Volume
| 36 | |
| 3 | Author
| H. Kisch, C. Krüger, A. Trautwein | Requires cookie* | | | Title
| Übergangsmetallkomplexe von Diazenen, XVI [1] Struktur und Mößbauerdaten von (2.3-Diazanorbornen)Fe3(CO)9 Transition Metal Complexes of Diazenes, XVI [1] Structure and Mössbauer Data of (2,3-Diazanorbornene)Fe3(CO)g | | | | Abstract
| The molecular structure of (2,3-diazanorbornene)Fe3(CO)9 consists of a triangular Fe3(CO)g group bound to the diazene unit. The seven-coordinated Fe(CO)3 group forms two Fe-N bonds with lengths of 1.974 and 1.965 Ä, each of the two six-coordinated Fe(CO)3 groups has slightly shorter Fe-N-bonds of 1.898 and 1.903 Ä. One Fe-Fe distance, 2.612Ä, is longer than the two other ones, 2.572 and 2.582 A, which are in the range of typical single bonds. The presence of seven-and six-coordinated iron carbonyl groups is also demonstrated by the Mössbauer spectrum showing signals with quadrupole splittings of 1.23 and 0.78, 0.62 ± 0.01 mm/s, respectively. | | | |
Reference
| Z. Naturforsch. 36b, 205—207 (1981); eingegangen am 2. Dezember 1980 | | | |
Published
| 1981 | | | |
Keywords
| Diazenes, Iron Cluster, X-ray, Mössbauer Data | | | |
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| default:Reihe_B/36/ZNB-1981-36b-0205.pdf | | | | Identifier
| ZNB-1981-36b-0205 | | | | Volume
| 36 | |
| 5 | Author
| Heindirk Tom Dieck, Michael Svoboda, Thomas Greiser | Requires cookie* | | | Title
| Bis | | | | Abstract
| (diazadien)metall(0)-Komplexe, IV [1] Nickel(0)-bis(chelate) mit aromatischen N-Substituenten Bis(diazadiene)metal(0) Complexes, IV [1] Nickel(0)-bis(chelates) with Aromatic N-Substituents R1R2 With N-aromatic substituted diazadienes (DAD) R 3 -N=C—C = N-R 4 (R 1 , R 2 = H, CH3 and R 3 = R 4 = aryl) nickel(O) forms complexes of composition (DAD)2Ni which are prepared preferably by reduction of Ni(II) salts in the presence of DAD. The groups R 1 , R 2 and/or the o-substituents of the aryl system determine the conformation of the DAD and its sterical ligand properties. An X-ray structure analysis of (DAD)2Ni 17 (DAD = glyoxal-bis(2,6-dimethyl-phenylimine)) shows a dihedral angle of 44° between the two chelate planes. With twisted N-aryl substituents nickel seems to prefer planar coordination (formal low spin Ni(II)) of two DADs over tetrahedrally coordinated formal nickel(O) state. | | | |
Reference
| Z. Naturforsch. 36b, 823—832 (1981); eingegangen am 27. Mai 1980 | | | |
Published
| 1981 | | | |
Keywords
| Diazadien Nickel Complexes, Planar ^ Tetrahedral Interconversion, X-ray | | | |
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| default:Reihe_B/36/ZNB-1981-36b-0823.pdf | | | | Identifier
| ZNB-1981-36b-0823 | | | | Volume
| 36 | |
| 7 | Author
| R. Hilgenfeld, W. Saenger | Requires cookie* | | | Title
| Stabilization of a Host-Guest Type Complex by Bifurcated Hydrogen Bonds : 18-crown-6 * (2,4-Dinitrophenylhydrazine)2 a | | | | Abstract
| The X-ray structure of the 1:2 host-guest complex between 1,4,7,10,13,16-hexaoxa-cyclooctadecane (18-crown-6) and 2,4-dinitrophenylhydrazine is reported. Crystallo-graphy data are: space group P2i/c, a = 8.557(2), b = 16.745(6), c = 12.387(4) Ä, ß = 117.08(13)°, Z = 2, Dm = 1.37 g • cm" 3 , Dc = 1.387 g • cm-3 , m.p. 414 K (decomp.). The present B is 0.11 for 1733 diffractometer data. In the complex, the two 2,4-dinitrophenylhydrazine molecules are located "above" and "below" the plane of the hexaether and related by an inversion centre. They interact with the macrocyclic host via N-H---0 hydrogen bonds, two of which are bifurcated. All the ether oxygens of the crown serve as hydrogen bond acceptors. | | | |
Reference
| Z. Naturforsch. 36b, 242—247 (1981); received October 28 1980 | | | |
Published
| 1981 | | | |
Keywords
| Crown Ether, Dinitrophenylhydrazine Complex, Bifurcated Hydrogen Bonds, X-ray | | | |
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| default:Reihe_B/36/ZNB-1981-36b-0242.pdf | | | | Identifier
| ZNB-1981-36b-0242 | | | | Volume
| 36 | |
| 9 | Author
| ErnstOtto Fischer, Willi Kleine, Werner Schambeck, Ulrich Schubert | Requires cookie* | | | Title
| Übergangsmetall-Garben-Komplexe, CXXI [1] Fluorcarbenkomplexe des Mangans Transition Metal Car bene Complexes, CXXI [1] Fluorocarbene Complexes of Manganese | | | | Abstract
| The reaction between CH3CsH4Mn(C0)3 and LiN(C2Hs)2 and subsequent alkylation with [(C 2 H 5)30]BF4 affords CH 3 C5H4(CO)2MnC(OC2H5)N(C2H5)2. This carbene complex reacts with borontrihalides BX 3 (X = F, Cl) to yield [CH 3 C5H4(C0)2MnCN(C2H 5)2]BX 4 . Ad-dition of [(C 4 H 9) 4 N]F to this cationic carbyne complex results in the formation of CH3C5H4(CO)2MnC(F)N(C2H5) 2 . In the same way C 5 H5(C0)2MnC(F)C 6 H5 is prepared from [CsH^CO^MnCCeHslSbClß. Fluoride addition can be reversed by reaction of the latter carbene complex with BF3 to give [CsH5(CO)2MnCC6H5]BF4. In the X-ray structure of C5H5(C0)2MnC(F)C6H5 unusual bonding parameters are found, which are consistent with the easy cleavage of the C(carbene)-F bond. | | | |
Reference
| Z. Naturforsch. 36b, 1575—1579 (1981); eingegangen am 21. Juli 1981 | | | |
Published
| 1981 | | | |
Keywords
| Cationic Carbyne Complexes, Fluorcarbene Complexes, Fluoride Abstraction, X-ray | | | |
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| default:Reihe_B/36/ZNB-1981-36b-1575.pdf | | | | Identifier
| ZNB-1981-36b-1575 | | | | Volume
| 36 | |
| 10 | Author
| M. Veith, 0. Recktenwald | Requires cookie* | | | Title
| Cyclische Diazastannylene, X [1] Die Kristall-und Molekülstruktur eines Moleküls mit verzerrt-würfelförmigem Sn4N30-Käfig Cyclic Diazastannylenes, X [1] The Crystal and Molecular Structure of a Molecule with a Distorted Cube-Shaped SiLiNsO-Cage | | | | Abstract
| The crystal and molecular structure of (me3CN)3(me3A10)Sn4 has been determined from three-dimensional X-ray data (4-circle diffractometer, R — 0.048). The crystals are mono-clinic, space group P2i/c, with cell dimensions a = 1017.4(5), b — 1488.5(7), c = 1748(1) pm, jS—91.5(1)° and Z — 4. The molecules approach 3m point-symmetry and include a SruNsO-cage, the atoms occupying the corners of a distorted cube formed by two, differently sized, interpenetrating concentric tetrahedra of tin and nitrogen/oxygen atoms. The nitrogen atoms are attached to tert-butyl groups, whereas the oxygen atom of the cage acts as a base towards the aluminiumtrimethyl group. Typical bond distances and angles (mean values) are: Sn-N = 219.9, Sn-0 = 220.3 pm; N-Sn-N = 81.2°; N-Sn-0 = 79.0°; Sn-N-Sn = 98.8° and Sn-O-Sn -100.2°. | | | |
Reference
| Z. Naturforsch. 36b, 144—149 (1981); eingegangen am 14. Oktober 1980 | | | |
Published
| 1981 | | | |
Keywords
| Molecular Tin(II) Compounds, Iminostannylenes, Cubane-Like Cage, X-ray, Molecular Structure | | | |
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| default:Reihe_B/36/ZNB-1981-36b-0144.pdf | | | | Identifier
| ZNB-1981-36b-0144 | | | | Volume
| 36 | |
| 11 | Author
| Lothar Weber, Dorothee Vehreschild-Yzermann, Carl Krüger+, Gotthelf Wolmershäuser+@bullet | Requires cookie* | | | Title
| ÜbergangsmetaU-Schwefelylid-Komplexe, XI [1] Struktur und Reaktivität von ^ 5 -Thiacyclohexadienyl-l-oxid-chrom-KompIexeii Transition Metal Sulfur Ylide Complexes, XI [1] Structure and Reactivity of 77 5 -Thiacyclohexadienyl-l-oxide Complexes of Chromium | | | | Abstract
| The X-ray crystal and molecular structure of tetraethylammonium-tricarbonyl-(3,5-diphenylthiacyclohexadienyl-l-oxide)chromate has been determined. This organo-metallic anion can be nitrosylated to yield neutral [7y 5 -C5H3(C6H5)2SO](CO)2(NO)Cr. Further carbonyl displacement in this compound is achieved by treatment with pyridin or phos-phanes in the presence of triethylamineoxide. | | | |
Reference
| Z. Naturforsch. 36b, 198—204 (1981); eingegangen am 4. September 1980 | | | |
Published
| 1981 | | | |
Keywords
| X-ray, 3, 5-Diphenylthiacyclohexadienyl-l-oxide, Nit rosy lation, Amineoxide Assisted Carbonyl Displacement | | | |
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| default:Reihe_B/36/ZNB-1981-36b-0198.pdf | | | | Identifier
| ZNB-1981-36b-0198 | | | | Volume
| 36 | |
| 13 | Author
| PeterM. Kaiser®, Reinhard Nesper, Karl-Friedrich Tebbe, Herbert Witzel»- | Requires cookie* | | | Title
| Pyridin-4-on-Nueleosid + : Stabilisierung der Struktur im Kristall und in wäßriger Lösung Pyridine-4-on Nucleoside: Stabilisation of the Structure in the Crystal and in Aqueous Solution | | | | Abstract
| C10H13NO5 • H2O is monoclinic, space group P2i with a = 773.7 pm, b = 814.6 pm, c= 932.6 pm, ß = 109.36° at 143 K, Z = 2. The crystal structure has been refined to R =0.031 with 1340 counter reflections. Features of this nucleoside include an orientation of the base at the glycosidic bond N(l)-C(l') in the anii-range (52.5°), a ribosyl moiety in the C(2')-endo(S) conformation and in contrast to many other nucleosides a trans arrange-ment at C(4')-C(5'). This unusual conformation is stabilized by a distinct H-bonding scheme including the water molecule and the oxygen of the adjacent pyridin-4-on ring system. NMR data indicate on the other side that in solution the conformation of the nucleoside is anti/g + similar to that of other pyrimidine nucleosides. The 5'-OH group replaces the water molecule in the crystal. The preferred anti position of the base cannot be explained by an interaction of H(2,6) of the base with the 5'-OH group or the C(4) oxygen. Both protons which couple with H(3,5) coalesce in a single sharp doublet. Water entropy seems to be the decisive factor for the stabilization of the anti/g+ conformation in aqueous solution. | | | |
Reference
| Z. Naturforsch. 36b, 1632—1639 (1981); eingegangen am 3. Juli 1981 | | | |
Published
| 1981 | | | |
Keywords
| Pyridine-4-on Nucleoside, X-ray, NMR Spectra, Conformational Differences, Water Entropy | | | |
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| default:Reihe_B/36/ZNB-1981-36b-1632.pdf | | | | Identifier
| ZNB-1981-36b-1632 | | | | Volume
| 36 | |
| 14 | Author
| Rudolf Hansel, Faeis Khaliefi, Andrew Pelter | Requires cookie* | | | Title
| 3.5-Dihydroxy | | | | Abstract
| 6.7.8-trimethoxyflavon aus Heiichrysum graveolens: Bestätigung der Konstitution Confirmation of the Structure of an Extractive from Helichrysum graveolens as 3,5-Dihydroxy-6,7,8-trimethoxyflavone | | | |
Reference
| Z. Naturforsch. 36b, 1171—1172 (1981); eingegangen am 12. Mai 1981 | | | |
Published
| 1981 | | | |
Keywords
| 3, 5-Dihydroxy-6, 7, 8-trimethoxyflavone, Isomeric a-Hydroxybenzalcumaranone, X ray, NMR Spectra | | | |
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| default:Reihe_B/36/ZNB-1981-36b-1171.pdf | | | | Identifier
| ZNB-1981-36b-1171 | | | | Volume
| 36 | |
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