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1992 (202)
1Author    D. BrinkmannRequires cookie*
 Title    Probing the Electronic Structure of Y-Ba-Cu-O Superconductors by Copper NQR/NMR  
 Abstract    The paper discusses some NQR/NMR studies performed on Y-Ba-Cu-O superconductors at the University of Zürich. It is shown how the resonance methods can yield information on electronic properties of quite different character. The review deals with: (1) the temperature and pressure dependence of Cu NQR frequencies in YBa 2 Cu 4 O g (1-2-4); (2) an NQR study of the properties of Ca substituted 1-2-4; (3) the temperature dependence of the Cu Knight shifts in 1-2-4; (4) the NMR of plane Cu2 in the paramagnetic state of YBa 2 Cu 3 0 6 ; (5) the dependence on temperature, pressure and orientation of the Cu spin-lattice relaxation in 1-2-4. 
  Reference    Z. Naturforsch. 47a, 1—6 (1992); received September 20 1991 
  Published    1992 
  Keywords    NQR, NMR, High-temperature superconductors, Knight shift, Spin-lattice relaxation 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0001.pdf 
 Identifier    ZNA-1992-47a-0001 
 Volume    47 
2Author    K. Asayama, Y. Kitaoka, G.-Q ZhengRequires cookie*
 Title    NQR and NMR in High T c Superconductors  
 Abstract    Recent NQR and NMR experiments on La 2 _ x Sr ;c Cu0 4 , YBa 2 Cu 3 0 7 , Tl 2 Ba 2 Cu0 6+) , and other compounds are reviewed. The antiferromagnetic spin fluctuations decrease in the order of La, Y, T1 compounds. In the normal state the T-dependence of (T^Ty 1 is considered to follow the Curie-Weiss law at high temperature and the (Ti 7") = const law at low temperature. The T dependence of 1/T X below T c suggests strongly d-wave pairing. Correlations of the NQR frequency of 63 Cu and 17 0 with the antiferromagnetic spin fluctuations and the superconducting transition temperature are discussed. 
  Reference    Z. Naturforsch. 47a, 7—11 (1992); received October 16 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0007.pdf 
 Identifier    ZNA-1992-47a-0007 
 Volume    47 
3Author    W. Tröger, T. ButzRequires cookie*
 Title    Oxygen Diffusion in YBa 2 Cu 3 0 7 _ s Studied via 133 Ba(EC) 133 Cs Nuclear Quadrupole Interaction  
 Abstract    The oxygen diffusion in YBaXujO^,, was studied between 300 K and 1273 K in flowing oxygen by monitoring the 133 Ba(EC) Cs nuclear quadrupole interaction by time differential perturbed angular correlation. The data are analyzed in a model of two different nearest neighbour oxygen configurations and yield hopping rates, the energy barrier and the difference in free enthalpy between both states. In addition, we studied the reduced system YBa 2 Cu 3 0 6+£ . 
  Reference    Z. Naturforsch. 47a, 12—20 (1992); received August 9 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0012.pdf 
 Identifier    ZNA-1992-47a-0012 
 Volume    47 
4Author    YuA. Ossipyan, O. V. Zharikov, V. L. Matukhin, V. N. Anashkin, I. A. Safin, A. I. Pogorelcev, G. B. Teitelbaum, Yba, Cu, IodinationRequires cookie*
 Title    Cu NQR Study in a High-J c Superconductor YBa 2 Cu 3 0 6A l x  
 Abstract    NQR-spectra and nuclear relaxation of 63 Cu in ceramic samples of the Y-Ba-Cu-O system with various oxygen content have been compared with those in iodinated YBa 2 Cu 3 O eA . 
  Reference    Z. Naturforsch. 47a, 21—26 (1992); received August 8 1991 
  Published    1992 
  Keywords    NQR-spectra, Relaxation, Superconductivity 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0021.pdf 
 Identifier    ZNA-1992-47a-0021 
 Volume    47 
5Author    S. Gärtner, H. Riesemeier, Y. Kitaoka, V. Müller, K. Lüders, E. Kaldis, S. RusieckiRequires cookie*
 Title    Cu-NQR Frequencies and Linewidths in High-T c Superconductors  
 Abstract    The Cu-NQR lines of various high-T c superconductors at the Cu(2) site appear between 15 and 40 MHz. There exists an experimental correlation showing that the NQR frequency increases with decreasing T c . By comparison, it can be concluded from these results that a formal valence state of the Cu ion around 2 + is favourable for superconductivity. All lines exhibit a strong broadening compared to Cu0 2 crystals, which is attributed to lattice modulations within the Cu0 2 layers. This effect also influences the temperature dependence of the linewidth in YBa 2 Cu 3 0 7 _ a . 
  Reference    Z. Naturforsch. 47a, 27—29 (1992); received August 3 1991 
  Published    1992 
  Keywords    NQR, Superconductivity, High-T c compounds, Resonance frequency, Linewidth 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0027.pdf 
 Identifier    ZNA-1992-47a-0027 
 Volume    47 
6Author    P. J. Bray, Donghoon Lee, Gen De, G. L. Mao, Petersen, S. A. Feller, D. L. Bain, D. A. Feil, Ponnappa Pandikuthira, Sumit NijhawanRequires cookie*
 Title    NQR Studies of the Structure of Glasses and Crystalline Compounds  
 Abstract    Pure nuclear quadrupole resonance (NQR) spectroscopy at low frequencies (down to 275 kHz) has been used to investigate a number of borate, aluminate, and vanadate crystalline compounds and borate glasses. The values of the quadrupole coupling constants (Q cc) and asymmetry parameters (rj) are obtained with error limits that are one or two orders of magnitude less than those for values obtained from NMR spectra. New sites, not resolved in NMR spectra, have been detected for boron in borate glasses. 
  Reference    Z. Naturforsch. 47a, 30—38 (1992); received August 4 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0030.pdf 
 Identifier    ZNA-1992-47a-0030 
 Volume    47 
7Author    Alejandro OlivieriRequires cookie*
 Title    N Quadrupole Interactions in Nitrogen-Containing Ceramics. Effects on 29 Si NMR Line Shapes and Structural Implications  
 Abstract    Simulations of solid-state 29 Si NMR spectra in nitrogen-containing silicon ceramics and glasses are described. The range of SiN ;t 0 4 ._ x tetrahedra is covered, with emphasis on the experimental conditions needed to observe the effect of the incompletely averaged 29 Si, 14 N dipolar coupling. A simple equation is discussed concerning its use in the interpretation of these 29 Si spectra, including the computation of 14 N quadrupole coupling constants with its absolute sign. Key words: Residual 29 Si, 14 N dipolar coupling, 14 N Quadrupole coupling constants, 29 Si Solid-state NMR simulation. 
  Reference    Z. Naturforsch. 47a, 39—44 (1992); received July 31 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0039.pdf 
 Identifier    ZNA-1992-47a-0039 
 Volume    47 
8Author    M. J. PonnambalamRequires cookie*
 Title    Electric Field Gradient in Aluminium due to Vacancy and Muon  
 Abstract    The electric field gradients (EFG) in aluminium due to a monovacancy and the interstitial muon are evaluated. The valence effect EFG q v is calculated using perturbed electron density ön(r) values obtained from density functional theory in an analytic expression which is valid at all distances from the impurity. The size effect EFG q s is evaluated using a new oscillatory form for the near neighbour (nn) displacements. The numerical values of q s are computed using fractional nn displacements available in the literature. For the total EFG good agreement with experiment is obtained without the use of any parameter. 
  Reference    Z. Naturforsch. 47a, 45—48 (1992); received July 29 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0045.pdf 
 Identifier    ZNA-1992-47a-0045 
 Volume    47 
9Author    J. M. Keartland, I. P. Goudemond, G.C K Fölscher, M.J R HochRequires cookie*
 Title    Nucleus-Carrier Interactions in the Group V Semimetals: Dependence on Temperature and Pressure  
 Abstract    A review is given of pulsed NQR spin-lattice relaxation measurements on the rhombohedral semimetals, arsenic (As) and antimony (Sb). The nuclear spin-lattice relaxation time 7\ has been measured in the temperature range 100 mK-600 K. The data follow the Korringa relation at low temperatures, but deviations from this relation are found as the temperature is increased. The results are quantitatively explained by considering interactions of the nuclei with the carriers at the Fermi surface. Above the Debye temperature (0 D) the data may be understood by including a two phonon process in the analysis. The relaxation data for As and Sb are found to scale with d D . T x has been measured for As at 295 K in the pressure range 0-10 kbar. The results are discussed in terms of changes in the Fermi surface parameters. PACS numbers: 76.60. Es; 76.60Gv; 71.20Cf. 
  Reference    Z. Naturforsch. 47a, 49—53 (1992); received August 27 1991 
  Published    1992 
  Keywords    Semimetals, Pulsed NQR, Nucleus-carrier interactions, Nucleus-phonon inter-actions, Fermi surface parameters 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0049.pdf 
 Identifier    ZNA-1992-47a-0049 
 Volume    47 
10Author    Marco Lenck, Alarich WeissRequires cookie*
 Title    Cesium Iodometallates(III), Cs 3 M 2 I 9 , with M = Rare Earth. A Structural Investigation by 127 1 NQR  
 Abstract    The 127 NQR spectra of cesium enneaiododimetallates Cs 3 M 2 I 9 , M = Dy, Ho, Er, Yb, Y and Tb, Sm, Nd, Pr have been studied as a function of temperature. The compounds are characterized by X-ray powder diffraction, too. The first group of compounds, M = Dy • • • Y, belongs to the family of Cs 3 Cr 2 Cl 9 -type enneahalogenodimetallates (III). The crystal structure of the second group, M=Tb---Pr, is less symmetric, as in the 127 I NQR the presence of two crystallographically independent iodines shows up. Nuclear quadrupole coupling constants for the terminal and bridging halogens have been calculated from the NQR frequencies. The dependence of the NQR frequencies and of the crystal structure from the radius of the RE 3e -ion is discussed. The NQR spectra reveal phase transitions of the investigated enneaiododimetallates (III), for which T lr also depends on r(RE 3 ®). Positive temperature coefficients of the 127 I have been found and the influence of 7i-bond character is considered. 
  Reference    Z. Naturforsch. 47a, 54—64 (1992); received July 30 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0054.pdf 
 Identifier    ZNA-1992-47a-0054 
 Volume    47 
11Author    Hideta Ishihara, Koichi Watanabe, Ayako Iwata, Koji Yamada, Yoshihiro Kinoshita, Tsutomu Okuda, V. G. Krishnan, Shi-Qi Dou, Alarich WeissRequires cookie*
 Title    NQR and X-ray Studies of [N(CH 3 ) 4 ] 3 M 2 X 9 and (CH 3 NH 3 ) 3 M 2 X 9 (M = Sb,Bi; X = Cl,Br)  
 Abstract    35 C1, 81 Br, 121 Sb, and 209 Bi NQR of the title compounds was observed. According to the results of the temperature dependences of NQR frequencies and the DTA measurements, phase transitions take place in [N(CH 3),] 3 Bi 2 Br 9 (7^ r =183K), [N(CH 3) 4 ] 3 Bi 2 Cl 9 (T lr = 155K), and (CH 3 NH 3) 3 Bi 2 Cl 9 (T tr = 200 and 249 K). 2 D NMR spectra for partially deuterated (CH 3 ND 3) 3 Bi,Br 9 showed that the phase transitions in this compound are related to the motion of the methylammonium cations. Single-crystal X-ray work at room temperature shows that the space group for [N(CH 3) 4 ] 3 Sb 2 Cl 9 is_P6 3 /mmc with a = 925.1 pm, c = 2173.4 pm, Z = 2. For (CH 3 NH 3) 3 Sb 2 Br 9 the space group is P3ml with a = 818.8 pm, c = 992.7 pm, Z = 1; in both cases the cations show dynamical disorder. The Rietveld analysis of the powder X-ray diffraction for (CH 3 NH 3) 3 Bi 2 Br 9 reveals the space group P3ml with a = 821.0, c — 1000.4 pm, Z = 1 at room temperature; the compound is isomorphous with (CH 3 NH 3) 3 Sb 2 Br 9 . The crystal symmetries of the low-temperature phases of (CH 3 NH 3) 3 Bi 2 Br 9 and [N(CH 3) 4 ] 3 Bi 2 Br 9 were deduced from the results of the NQR spectroscopy. 
  Reference    Z. Naturforsch. 47a, 65—74 (1992); received August 3 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0065.pdf 
 Identifier    ZNA-1992-47a-0065 
 Volume    47 
12Author    Gary Wulfsberg, Debra Jackson, William Ilsley, Shi-Qi Dou, Alarich Weiss, John GagliardiRequires cookie*
 Title    Coordination of OrfÄö-Chlorines in Copper (I) and Silver (I) 2,6-Di-and 2,4,6-Trichlorophenolates Crystal Structure of (2,4,6 -Trichlorophenolato-O, CI) bis (triphenylphosphine) silver (I)  
 Abstract    The crystal structure of (Ph 3 P) 2 AgOC 6 H 2 Cl 3 (I) is reported along with the syntheses and 35 C1 and 63 Cu NQR spectra of I and several related silver (I) and copper (I) 2,6-di-and 2,4,6-trichlorophe-nolates containing phosphines, phosphites, and pyridine as co-ligands. I crystallizes in space group P2 Jc with a= 16.692(4) Ä, b= 17.942 (4) A, c= 12.857 (3) Ä, /? = 97.60 (1)°, F = 3816.68 Ä 3 , and Z = 4. The final R (F) = 0.0475 and R (W) = 0.0396. Ag is coordinated in a trigonal planar geometry by the P atoms of the two triphenylphosphine ligands and the O atom of the chlorophenolate; Ag is then capped by one ortho-chlorine of the trichlorophenolate ligand at a distance of 3.160 (2) Ä. In the 35 C1 NQR spectrum of this compound the two orf/io-chlorines of the trichlorophenolate ligand have a large frequency difference of 1.500 MHz, indicating that one ortho-chlorine is coordinated to the silver; 35 C1 NQR spectra of related complexes are also presented and discussed. The 35 C1 NQR frequency differences of coordinated and non-coordinated orr/io-chlorines in metal chlorophenolates correlate well with the metal-chlorine distances but not with the metal-chlorine-carbon bond angles. A different correlation is found for the silver complexes of dichloroalkanes; possible reasons for this are discussed. 
  Reference    Z. Naturforsch. 47a, 75—84 (1992); received July 15 1991 
  Published    1992 
  Keywords    Nuclear quadrupole resonance, Chlorophenolates, Crystal structure, Chlorocarbons as ligands, Silver(I) complexes 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0075.pdf 
 Identifier    ZNA-1992-47a-0075 
 Volume    47 
13Author    T. Butz, W. Tröger, Th Pöhlmann, O. NuykenRequires cookie*
 Title    The Nuclear Quadrupole Interaction of 199m Hg-Cysteine and 199m Hg-tert-butyl-mercaptide  
 Abstract    The nuclear quadrupole interaction of 199m Hg in Hg-cysteine and Hg-tert-butyl mercaptide was determined at room temperature by perturbed angular correlations. The dramatic difference in the interaction strength between both compounds is a result of the two-fold and four-fold sulfur coordination, respectively. Moreover, we compared the preparation of Hg-cysteine using a Hg: cys-teine ratio of 1:2 and using carrier-free 199m Hg from ISOLDE/CERN and obtained identical results. 
  Reference    Z. Naturforsch. 47a, 85—88 (1992); received August 3 1991 
  Published    1992 
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 Identifier    ZNA-1992-47a-0085 
 Volume    47 
14Author    T. Fraenzke, Butz, A. LerfRequires cookie*
 Title    Th  
 Abstract    The lllm Cd nuclear quadrupole interaction in CdCl 2 and CdCl 2 • H 2 0 was determined in the temperature range from 77 K to 783 K and 363 K, respectively, by time differential perturbed angular correlation. In addition, both the crystallization of the monohydrate from solution and its dehydration were monitored in situ. 
  Reference    Z. Naturforsch. 47a, 89—95 (1992); received August 6 1991 
  Published    1992 
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 Identifier    ZNA-1992-47a-0089 
 Volume    47 
15Author    Juan Murgich, Yosslen Aray, Edgar Ospina, Rico, Ismardo BonaldeRequires cookie*
 Title    N NQR in 1,10-Phenanthroline and Dicyano bis(l,10-phenanthroline)iron(III)  
 Abstract    14 N NQR spectra of 1,10-phenanthroline and of dicyano bis(l,10-phenanthroline)iron(lll) were obtained at room temperature. An analysis based on the shifts of the NQR frequencies and in the topology of the charge distribution in a model (pyridine) showed that the complex formation produces a strong decrease in the N valence shell nonbonded maximum and an increase in the bonded density along each of the N-H bond directions. The NQR spectrum showed that the complex formation produces only small changes in the charge distribution of the cyanide groups. 
  Reference    Z. Naturforsch. 47a, 96—98 (1992); received August 3 1991 
  Published    1992 
  Keywords    14 N NQR, Phenanthroline, Complex, Charge distribution, Topology 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0096.pdf 
 Identifier    ZNA-1992-47a-0096 
 Volume    47 
16Author    Hiromitsu Terao, Tsutomu Okuda, Aya Minami, Takashi Matsumoto, Yoshio TakedaRequires cookie*
 Title    Br and l27 I NQR Studies of (CH 3 NH 3 ) 2 HgBr 4 and (CH 3 NH 3 ) 2 HgI 4  
 Abstract    The 81 Br and 127 I NQR frequencies in (CH 3 NH 3) 2 HgBr 4 and (CH 3 NH 3) 2 HgI 4 , respectively, have been recorded from above 77 K to around room temperature. The resonance lines exist in a wide range of frequencies. An unusual temperature dependence of the resonance frequencies has been observed. Small 1 H-2 D isotope effects have been observed between (CH 3 ND 3) 2 HgBr 4 and (CH 3 NH 3) 2 HgBr 4 . Both negative and positive frequency differences between the deuterated and the nondeuterated compound have been observed at 77 K. The relatively large asymmetry parameters in the iodine compound decrease with increasing temperature, indicating the existence of H-bonds. The present results are interpreted qualitatively by considering the effects of H-bonding, N-H • • • X, between the halogen atoms and the CH 3 NH 3 ions which may undergo large molecular motions. It is suggested that not only frequency-lowering but also frequency-rising effects may be produced, depending on the direction of the H-bond, i.e., the angle between the Hg-X bond and the X • • • H bond. 
  Reference    Z. Naturforsch. 47a, 99—105 (1992); received October 8 1991 
  Published    1992 
  Keywords    81 Br NQR, 127 I NQR, Anomalous temperature dependence, r H-2 D isotope effect, H-bonding, Motions of CH 3 NH+ 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0099.pdf 
 Identifier    ZNA-1992-47a-0099 
 Volume    47 
17Author    Augustin Habiyakare, EdwinA C Lücken, Gerald BernardinelliRequires cookie*
 Title      
 Abstract    The temperature-dependence of the 63 Cu and 127 I NQR spectra of 6;'s(2-picoline) Copper(I) Iodide reveals the existence of a phase change at 250 K. An X-ray crystallographic study of the low-temperature phase reveals that the iodine-bridged dimeric structure, which was observed at room-temperature, is retained in the low temperature phase but that the bond-lengths and, partic-ularly, the bond-angles of the central four-membered ring are considerably modified. 
  Reference    Z. Naturforsch. 47a, 106—110 (1992); received July 29 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0106.pdf 
 Identifier    ZNA-1992-47a-0106 
 Volume    47 
18Author    G. K. Semin, A. M. Raevsky, S. I. Kuznetsov, T. L. Khotsyanova, S. I. GushchinRequires cookie*
 Title    Br NQR Spectra of the Impurity Molecules of Tetrabromides of Group IV Elements in the Matrix Crystals of Group IV Element Halides  
 Abstract    Changes in 79 Br NQR spectra of the impurity molecules EBr4 (2-5% mol) (E = C, Si, Ti, Ge, Sn) in the matrix crystals of group IV element tetrahalides EHal4 (E = Si. Ti, Ge, Sn; Hal = CI, Br) were studied at 77 K. The mixtures of these components are substitution solid solutions (SS), which was proved by the appearance of characteristic satellites in the NQR spectra of the matrix crystals. Changes in the Br NQR spectra of the impurity molecules were analyzed from the viewpoint of packing factors and the type of nearest environment. In the temperature range 77-270 K an abnormal temperature dependence of the 79 Br NQR frequencies of TiBr4 impurity in SiBr4 matrix was observed for both lines of the cubic phase. The temperature dependence of the 79 Br NQR frequencies of SiBr impurity in TiBr4 matrix is normal. 
  Reference    Z. Naturforsch. 47a, 111—116 (1992); received December 18 1991 
  Published    1992 
  Keywords    79, 81 Br NQR, Solid solutions, Group IV element tetrahalides, Temperature depen-dence of NQR frequencies 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0111.pdf 
 Identifier    ZNA-1992-47a-0111 
 Volume    47 
19Author    Tanja Pietraß, PaulK. Burkert, HansH. KarschRequires cookie*
 Title    Li-Solid-State-NMR of [LiCN^^^N'-Tetramethylethylenediamine)! C10 4 and [Li (N,N,N', N'-Tetr amethylethy lenediamine) 2 1 AI (CH 3 ) 4  
 Abstract    The temperature dependent 7 Li-solid-state-NMR spectra of the two compounds [Li(N,N,N',N'-tetramethylethylenediamine)]C104 and [Li(N,N,N\N^etramethylethylenediamine)2]Al(CH3)4 are presented. Both compounds were investigated in the temperature range 160 K ^ T ^ 360 K. Above room temperature, the spectra for the tetramethylaluminate show the typical line shape for a first-order quadrupolar-disturbed central transition with an axially symmetric asymmetry parame-ter and a slightly positive temperature dependence of the quadrupole coupling constant. The mean temperature coefficient <x = +9 • 10~ 4 K _1 . The quadrupole coupling constant is in the range of 36-39 kHz. In the temperature range 240 K ^ 7^275 K the quadrupolar splitting cannot be re-solved. Below 240 K the quadrupole coupling constant is about 100 kHz. Contrarily, in the Per-chlorate the quadrupole coupling constant is 75 kHz and is temperature independent. With increasing temperature the satellites lower in intensity and the central transition undergoes motional narrowing. 
  Reference    Z. Naturforsch. 47a, 117—119 (1992); received July 27 1991 
  Published    1992 
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 Identifier    ZNA-1992-47a-0117 
 Volume    47 
20Author    ValentinP. Feshin, MikhailG. VoronkovRequires cookie*
 Title    An NQR Study of Tetrachloride Complexes of Group IVA Elements  
 Abstract    The results of an NQR study on the MC14 complexes (M = Si, Ge, Sn) with organic heteroatom ligands (including those containing several coordination centers) are summarized: chloroanhydrides of unsaturated, aromatic and heteroaromatic carboxylic acids; alkylarylethers, ketones, aryl-dichlorophosphates, nitrogen-containing compounds, etc. The octahedral or trigonal-bipyramidal structure of these complexes has been established, and the factors influencing the formation and structure of such complexes (component ratio, character of ligand and M atom) have been analyzed. The structure of several complexes may vary with time or depend on the crystallization condition of the system. Some of these results indicate coordination isomerism. The quantitative ratios be-tween the 35 C1 NQR frequency shifts of ligand and axial Sn-Cl bonds in trigonal-bipyramidal RCOC1 • SnCl4 complexes relative to the initial component frequencies have been found. 
  Reference    Z. Naturforsch. 47a, 120—124 (1992); received December 16 1991 
  Published    1992 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0120.pdf 
 Identifier    ZNA-1992-47a-0120 
 Volume    47 
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