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1Author    Claudia FriedrichRequires cookie*
 Title    Zur Stereochemie des freien Elektronenpaares in Verbindungen des vierwertigen Tellurs: Verzerrtes TeCI62"-Oktaeder in |H  
 Abstract    ,N (C H 2),NH3lTeCI," regulär oktaedrisches Anion in | HjINfCHjliNHilSnCI,, On the Stereochemistry of Lone Pair Electrons in Com pounds with Tetravalent Tellurium: D istorted TeCl62~-Octahedron in [H3N (C H 2)3N H 3]T eCl6, Regular Octahedral A nion in [H3N (C H 2)3N H 3]SnC l6 W alter Abriel* Using 293 K diffractom eter intensity data, the structures o f [H 3N (C H 2)3N H 3]TeCl6 and [H3N (C H 2)3N H 3]SnCl6 have been determ ined by single crystal X-ray technique and refined to a 
  Reference    Z. Naturforsch. 40b, 1691 (1985); eingegangen am 30. August 1985 
  Published    1985 
  Keywords    Lone Pair Electrons, Tellurates, Stannates, Crystal Structure 
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 TEI-XML for    default:Reihe_B/40/ZNB-1985-40b-1691.pdf 
 Identifier    ZNB-1985-40b-1691 
 Volume    40 
2Author    Andre Du Bois, Walter AbrielRequires cookie*
 Title    Zur Stereochemie des freien Elektronenpaares in AX 6 E-Systemen, VIII* Statisch verzerrte Anionen in [H 3 N(CH2)3NH3]3(BiX 6 ) 2 (H 2 0) 2 mit X = Cl, Br On the Stereochemistry of the Lone-Pair Electrons in AX 6 E-Systems, VIII Statically Distorted Anion in [H 3 N(CH 2 )3NH 3 ]3(BiX 6 ) 2 (H 2 0) 2 with X = Cl, Br  
 Abstract    Using 293 K diffractometer intensity data, the crystal structures of fH 1 N(CH 2) 3 NH 3 ] 3 (BiX 6) 2 (H 2 0) 2 with X -Cl, Br have been determined by single crystal X-ray technique and refined to a final R w of 0.027 and 0.043, respectively. The structures are isotypic, space group P2,/c, Z = 2 with a = 14.415(1). b = 9.7401(7), c = 12.4609(9)Ä, ß = 105.997(8)°for X — Cl and a = 14.794(2), b = 10.127(2), c = 12.853(2)Ä, ß = 105.68(2)° for X -Br. Statically distorted BiX,, 3_ -octahedra confirm the symmetry rules for the stereochemistry of the lone pair electrons in AX ft E-systems. Basic structural data for all compounds containing BiX 6 3_ and SbX h 3 
  Reference    Z. Naturforsch. 43b, 1003—1009 (1988); eingegangen am 22. Februar 1988 
  Published    1988 
  Keywords    Lone Pair Electrons, Bismutates, Crystal Structure 
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 TEI-XML for    default:Reihe_B/43/ZNB-1988-43b-1003.pdf 
 Identifier    ZNB-1988-43b-1003 
 Volume    43 
3Author    Makoto Kaga, Piotr Koziol, Tetsuo Asaji, Daiyu NakamuraRequires cookie*
 Title    Electric field Gradient Modulation by Motion of Lone-Pair Electrons in [(CH 3 ) 3 S] 2 MC1 6 (M = Pt, Sn) as a Possible Relaxation Mechanism of Chlorine Nuclear Quadrupole Resonance  
 Abstract    The temperature dependence of the chlorine NQR spin-lattice relaxation time T^was observed for trimethylsulfonium hexachlorometallates(IV), [(CH 3) 3 S] 2 MC1 6 (M = Pt, Sn), trimethylammonium hexachlorostannate(IV), [(CH 3) 3 NH] 2 SnCl 6 , and tetramethylphosphonium hexachlorostannate(IV), [(CH 3) 4 P] 2 SnCl 6 . The quadrupolar relaxation in [(CH 3) 3 NH] 2 SnCl 6 and [(CH 3) 4 P] 2 SnCl 6 can be described by the usual librational and reorientational motion of the complex anion at lower and higher temperatures, respectively. Besides T 1Q due to these two mechanisms, T 1Q minimum was observed at ca. 90 and 120 K for [(CH 3) 3 S] 2 PtCl 6 and [(CH 3) 3 S] 2 SnCl 6 , respectively, which is attributable to the electric field gradient modulation by the motion of the [(CH 3) 3 S] + cation having lone-pair electrons. The activation energies for the isotropic reorientation of the complex anion were determined as46,65, 59, and 60 kJ mol^ for [(CH 3) 4 P] 2 SnCl 6 , [(CH 3) 3 NH] 2 SnCl 6 , [(CH 3) 3 S] 2 PtCl 6 , and [(CH 3) 3 S] 2 SnCl 6 , respectively. 
  Reference    Z. Naturforsch. 45a, 1033—1037 (1990); received May 26 1990 
  Published    1990 
  Keywords    Nuclear Quadrupole Resonance, Spin-Lattice Relaxation, EFG Modulation, Lone-Pair Electrons 
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 TEI-XML for    default:Reihe_A/45/ZNA-1990-45a-1033.pdf 
 Identifier    ZNA-1990-45a-1033 
 Volume    45 
4Author    Walter AbrielRequires cookie*
 Title    Die Kristallstruktur von Te6OnCl2 The Crystal Structure of Te60iiCl2  
 Abstract    Crystals of the title compound are monoclinic (space group P2i/m) with a — 6.844(4) Ä, 6 = 6.800(4) Ä, c= 15.227(9) A, y= 120.19° and Z = 2. The structure contains infinite cationic [(Tei2C>22) 4+ ]oo -chains with three different sites for tellurium. There are three oxygen atoms in a y-tetrahedral arrangement around Tel, and four oxygen atoms in a y-trigonal-bipyramidal coordination around Te2 and Te3. 
  Reference    Z. Naturforsch. 36b, 405—409 (1981); eingegangen am 28. Januar 1981 
  Published    1981 
  Keywords    System Te02-TeCl4, Ternary Compounds, Crystal Structure, Lone-Pair Electrons 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0405.pdf 
 Identifier    ZNB-1981-36b-0405 
 Volume    36 
5Author    Requires cookie*
 Title    Die  
 Abstract    Kristallstruktur von [(CH3)4N]2TeCl6 und über die Einschlußverbindung [(CH3)4N]2(CH3CN)TeCl6 The Crystal Structure of [(CH 3)4N]2TeCl6 and the Inclusion Com pound [(CH3)4N]2(CH 3C N)TeCl6 W alter Abriel* Both title com pounds show an antifluorite-like arrangement o f (C H 3)4N + cations and TeC l62~ anions. The remaining octahedral holes in this array can be filled with C H 3CN m olecules forming the inclusion com pound by crystallization from C H 3CN solution. [(C H 3)4N ]2TeC l6 (space group F d 3c with a = 25.791(3) Ä at 265(5) K and Z = 32) contains almost regular TeCl62-octahedra. In contrast, in [(CH 3)4N ]2(C H 3C N)T eC l6 (space group Cmcm with a = 12.765(6), b = 14.349(7), c = 12.716(3) Ä and Z = 4) the anion is statically distorted with the approximate point symmetry 4 mm. A t tem peratures above 320 K the solvent m olecules can be rem oved yielding the F d 3c phase. Finally, structural relationships betw een antifluorite-like phases A 2B X 6 and elpasolites A 2B 'B X 6 considering halogenides and cyanides are discussed. 
  Reference    Z. Naturforsch. 41b, 592 (1986); eingegangen am 3. Februar 1986 
  Published    1986 
  Keywords    Crystal Structure, Tellurates, Inclusion C om pound, Lone Pair Electrons 
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 TEI-XML for    default:Reihe_B/41/ZNB-1986-41b-0592.pdf 
 Identifier    ZNB-1986-41b-0592 
 Volume    41 
6Author    W. Alter, Abriel, Ernst-Jürgen, Z. EhnderRequires cookie*
 Title    Vibronische Kopplung und dynamisch verzerrte Strukturen in Hexahalogenotelluraten(IV): Ergebnisse aus Tieftemperatur-Röntgenbeugungsuntersuchungen (300—160 K) und aus FTIR-spektroskopischen Experimenten (300—5 K) [1] Vibronic Coupling and Dynamically D istorted Structures in Hexahalogenotellurates(IV): Low Tem peratur X-Ray Diffraction (300—160 K) and FTIR-Spectroscopic (300—5 K) Results [1]  
 Abstract    From theoretical considerations a dynamically distorted octahedron as a result of vibronic coupling between the ground state and the first excited state should exist for 14 electron AX6E systems like TeX62-. A high symmetry crystal field yielding at least a center of symmetry for the Te position stabilizes this fluctuating structure, otherwise statical distortion will be observed. From X-ray diffraction experiments on antifluorite type compounds A 2TeX6 (A = Rb, Cs; X = Cl, Br) the averaged structure (m 3m symmetry) of the anions was found even at very low temperatures. The thermal parameters are not significantly different from those of similar S n X ^ -compounds. Distortions therefore are very small and are evident from FTIR spectroscopic meas­ urements only. Here very broad T lu-deformation vibration bands are observed down to tempera­ tures <10 K without splitting: A statically distorted species could not be frozen out. In contrast to XeF6 for TeX62~ the energy gap between the threefold, fourfold or sixfold minima of the potential surface (according to the symmetry of one component of the T ,u-vibration) is very small and shifted to temperatures lower than reached with the devices used for these experiments. 
  Reference    Z. Naturforsch. 42b, 1273—1281 (1987); eingegangen am 24. Juni 1987 
  Published    1987 
  Keywords    Lone Pair Electrons, Vibronic Coupling, Pseudo Jahn-Teller-Effect, Tellurates 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-1273.pdf 
 Identifier    ZNB-1987-42b-1273 
 Volume    42 
7Author    Walter AbrielRequires cookie*
 Title    On the Stereochemistry of the Lone-Pair Electrons in AX 6 E-Systems: Dynamically Distorted Anion in (NH 4 ) 2 SeBr 6 , Statically Distorted Anion in l,3-Propanediammonium-Hexabromoselenate(IV) (C 3 N 2 H 12 )SeBr 6  
 Abstract    Using 293 K diffractometer intensity data, the crystal structures of (NH 4) 2 SeBr 6 (1) and [H 3 N(CH 2) 3 NH 3 ]SeBr 6 (2) have been determined by single crystal X-ray technique and refined to a final R w of 0.049 and 0.040, respectively. The dark red crystals of 1 are cubic (space group Fm3m) with a = 10.478(2) Ä and Z = 4. This structure contains SeBe 6 2 ~ octahedra (point symmetry m3m, distance Se —Br: 2.577(2) Ä) in an antifluorite type arrangement of cations and anions. In contrast, the SeBr fi 2-ion in 2 is statically distorted (approximate point symmetry 3m, distance Se-Br min. 2,547(2), max. 2.595(2) Ä. The dark red crystals are orthorhombic (space group Pnma) with a = 17.795(3), b = 7.5037(6), c = 10.476(1) Ä and Z = 4. The results agree with the rules for the appearance of a static/dynamic stereochemical effect of the lone pair electrons given for TeX 6 2 " (X = Cl, Br, I) species (W. Abriel, Acta Crystallogr. B 42, 449 (1986)). Consequently these rules can be extended considering SeX 6 2-as well. Basic structural data for all compounds containing AX 6 2-ions (A = Se, Te; X = Cl, Br, I) known to date are given including the zl-values (R. D. Shannon, Acta Crystallogr. A 32, 751 (1976)) as a measure for the distortion of the octahedral anion. 
  Reference    Z. Naturforsch. 42b, 415—420 (1987); received November 24 1986/January 12 1987 
  Published    1987 
  Keywords    Lone Pair Electrons, Pseudo-Jahn-Teller Effect, Symmetry Rules, Selenates, Crystal Structure 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0415.pdf 
 Identifier    ZNB-1987-42b-0415 
 Volume    42