Go toArchive
Browse byFacets
Bookbag ( 0 )
Search Crystal andStructures in keywords [X]
Facet   Publication Year 1993  [X]
Results  43 Items
Sorted by   
Publication Year
41Author    Jörn Müller, Ke Qiao, Regina Schubert, M. Atthias TschampelRequires cookie*
 Title    ;r-01efin-Iridium-Komplexe, XVIII [1] Reaktionen von Bis[cycloocta-l,5-dien-//-chloro-iridium] mit w-Propyllithium in Gegenwart von Alkinen yr-Olefin Iridium Complexes, XVIII [1] Reactions of Bis[cycloocta-l,5-diene-/z-chloro-iridium] with n -Propyllithium in the Presence of Alkynes  
 Abstract    The reaction of [(cod)IrCl]2 (cod = //4-cycloocta-l,5-diene) with n-C3H7Li gives non-isola-ble (cod)IrH species by /3-elimination of (cod)Ir-n-C3H7 intermediates; the stable final prod­ ucts of further reactions with RC = CR highly depend on the nature of the substituents R. With R = Me the 6-endo-H-hexamethylcyclohexadienyl complex 1 is obtained together with the iridacyclopentadienyl compound 2 and known }[(cod)IrH]4C3H4} (3). In case of R = Et steric effects cause transfer of the hydridic hydrogen to the cod ligand, and the hexaethyl-benzene species 4 is isolated which was characterized by crystal structure analysis. The reac­ tion system with tolane again yields a 6-enJo-H-cyclohexadienyl complex (5). In all cases free substituted benzenes are formed as cyclotrimerization products of the alkynes. 
  Reference    Z. Naturforsch. 48b, 1558—1564 (1993); eingegangen am 15. Juli 1993 
  Published    1993 
  Keywords    Substituted Benzene, Cyclohexadienyl and Iridacyclopentadienyl Complexes, Synthesis, NMR Spectra, Crystal Structure 
  Similar Items    Find
 TEI-XML for    default:Reihe_B/48/ZNB-1993-48b-1558.pdf 
 Identifier    ZNB-1993-48b-1558 
 Volume    48 
42Author    Wolfgang Jeitschko, Jörg Wallinda, MartinV. Dewalsky, Ulrich WortmannRequires cookie*
 Title    Preparation, Properties, and Structure of the Polyphosphides VM4P16, NbNi4P16, and WNi4P16  
 Abstract    The title compounds were prepared by reacting powders of the binary transition metal alloys with phosphorus in a tin melt. They crystallize with a monoclinic structure of space group C 2/c, which was determined from single-crystal X-ray data; VNi4P16: a = 1956.0(3), b = 565.9(1), c = 1106.6(2) pm, ß = 100.99(1)°, R -0.020 for 1904 structure factors and 97 variable parameters; NbNi4P16: a = 1973.0(3), b = 571.2(3), c = 1117.2(2) pm, ß = 100.74(1)°, R = 0.023 for 2431 F-values and 97 variables; WNi4P16: a = 1964.2(3), b = 568.3(2), c = 1109.3(2) pm,/? = 101.04(2)°, R = 0.031 for 371 F-values and 43 variables. The T atoms (T = V, Nb, W) have eight P neighbors, which form a slightly distorted square antiprism, and the Ni atoms have appro­ ximately octahedral P coordination. The P atoms form novel P8 units, which consist of 6 -mem-bered rings with a P2 side chain. Chemical bonding is discussed on the basis of classical two-electron bonds. A comparison of the interatomic distances suggests that the Fermi level cuts through a band formed by antibonding nickel-phosphorus states. A band structure is propos­ ed, which also rationalizes the metallic conductivity and the Pauli paramagnetism of the com­ pounds. 
  Reference    Z. Naturforsch. 48b, 1774—1780 (1993); received July 291993 
  Published    1993 
  Keywords    Crystal Structure, Magnetic Properties, Electrical Conductivity, Chemical Bonding, Transition Metal Polyphosphides 
  Similar Items    Find
 TEI-XML for    default:Reihe_B/48/ZNB-1993-48b-1774.pdf 
 Identifier    ZNB-1993-48b-1774 
 Volume    48 
43Author    Magdolna Hargittai, Gabor JancsóRequires cookie*
 Title    Correlation of Crystal Structure and Vapor Composition of Metal Dihalides  
 Abstract    The presence of dimers in the vapor of metal dihalides, as seen in electron diffraction experiments, is found to be correlated with the crystal structure of the halide and with the difference in the heat of vaporization between monomers and dimers. If the dimeric molecule cannot be recognized as a unit in the crystal, dimers are not detected in the vapor. If dimeric molecules are discernible in the crystal, they will be observed in the vapor if their heat of vaporization is not greater than that of the monomer by more than 10kcal/mol. 
  Reference    Z. Naturforsch. 48a, 1000—1004 (1993); received July 20 1993 
  Published    1993 
  Keywords    Crystal structure, Vapor composition, Metal dihalides, Correlation of structure and vapor composition, Gas-phase electron diffraction 
  Similar Items    Find
 TEI-XML for    default:Reihe_A/48/ZNA-1993-48a-1000.pdf 
 Identifier    ZNA-1993-48a-1000 
 Volume    48