Search
Go toArchive
Browse byFacets
Bookbag ( 0 )
'NMR' in keywords
Modify Search
Results  89 Items
Sorted by   
1
2
3
4
5
Next
Section
expandZfN Section A (50)
expandZfN Section B (33)
expandZfN Section C (6)
Publication Year
2000 (5)
1999 (6)
1998 (10)
1997 (4)
1996 (9)
1995 (3)
1994 (1)
1993 (2)
1992 (6)
1991 (1)
more
1Author    Bernd WrackmeyerRequires cookie*
 Title    Organoborierung von Alkinylstannanen, VI [1] Alienbildung bei einer Deorganoborierung Organoboration of Alkynylstannanes, VI [1] Formation of an Allene by Deorganoboration  
 Abstract    The thermal decomposition of some l,l-bis(trimethylstannyl)-2-dialkylborylalkenes leads unexpectedly to substituted allenes. The structural information is based on *H, 11 B, 13 C and 119 Sn NMR data and also on the strong IR band at 1882 cm" 1 . 
  Reference    Z. Naturforsch. 33b, 385—389 (1978); eingegangen am 18. Januar 1978 
  Published    1978 
  Keywords    Deorganoboration, Allenes, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0385.pdf 
 Identifier    ZNB-1978-33b-0385 
 Volume    33 
2Author    S. Lewicki, B. Szafrańska, Z. PająkRequires cookie*
 Title    Molecular Motion in Solid Tetrapropylammonium Bromide and Iodide  
 Abstract    The proton NMR second moment and spin-lattice relaxation time for tetrapropylammonium bromide and iodide have been measured over a wide temperature range. A solid-solid phase transition related to the onset of cation tumbling was found for both salts and confirmed by DTA. In the low temperature phases methyl group reorientation was evidenced. For iodide a dynamic nonequivalence of the methyl groups and the onset of ethyl groups motion was also discovered. 
  Reference    Z. Naturforsch. 47a, 1115—1118 (1992); received July 14 1992 
  Published    1992 
  Keywords    NMR, Molecular motions, Phase transitions 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-1115.pdf 
 Identifier    ZNA-1992-47a-1115 
 Volume    47 
3Author    B. C. Sanctuary, M. Angala, S. K. Rish, N. AnRequires cookie*
 Title    Theory of NQR Pulses  
 Abstract    Pulses applied to spin systems with I > 1/2 in the absence of any external fields, the NQR case, are fundamentally different from NMR pulses. In particular, both rotating and counter-rotating components of the rf field must be kept in NQR, whereas only the "in phase" component need be retained in NMR. NQR pulses are illustrated for 7 = 3 / 2 in an axially symmetric electric field gradient (EFG). 
  Reference    Z. Naturforsch. 49a, 71—7 (1994); received October 27 1993 
  Published    1994 
  Keywords    NQR, Pulse, Density matrix, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/49/ZNA-1994-49a-0071.pdf 
 Identifier    ZNA-1994-49a-0071 
 Volume    49 
4Author    Barbara Szafrańska, Zdzisław PająkRequires cookie*
 Title    M  
 Abstract    o le c u la r M o tio n in S o lid T e tr a e th y l-a n d T e tra p ro p y la m m o n iu m T e tr a f lu o r o b o r a te s Proton and fluorine NMR second moments and spin-lattice relaxation times for polycrystalline tetraethyl-and tetrapropylammonium tetrafluoroborates have been measured over a wide range of temperatures. Solid-solid phase transitions were found for both compounds and confirmed by DSC. Methyl group C3 reorientation followed by more complex cation motions was evidenced in the low temperature phases. Overall cation reorientation characterises the high temperature phases of both compounds. Isotropic anion reorientation was found in both salts in both phases. 
  Reference    Z. Naturforsch. 50a, 584—588 (1995); received August 15 1994 
  Published    1995 
  Keywords    NMR, Molecular motions, Phase transitions 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/50/ZNA-1995-50a-0584.pdf 
 Identifier    ZNA-1995-50a-0584 
 Volume    50 
5Author    M. Grottel3, A. Kozakb, Z. PająkRequires cookie*
 Title    l H a n  
 Abstract    d 19F N M R S tu d y o f C a tio n a n d A n io n M o tio n s in G u a n id in iu m F lu o r o a n tim o n a te s Proton and fluorine NMR linewidths, second moments, and spin-lattice relaxation times of polycrystalline [C(NH2)3]2SbF5 and C(NH2)3SbF6 were studied in a wide temperature range. For the pentafluoroantimonate, C3-reorientation of the guanidinium cation and C4-reorientation of the SbF5 anion were revealed and their activation parameters determined. The dynamical inequivalence of the two guanidinium cations was evidenced. For the hexafluoroantimonate, two solid-solid phase transitions were found. In the low temperature phase the guanidinium cation undergoes C3 reorien­ tation while the SbF6 anion reorients isotropically. The respective activation parameters were derived. At high temperatures new ionic plastic phases were evidenced. 
  Reference    Z. Naturforsch. 50a, 742—748 (1995); received March 2 1995 
  Published    1995 
  Keywords    NMR, Molecular Motions, Phase transitions 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/50/ZNA-1995-50a-0742.pdf 
 Identifier    ZNA-1995-50a-0742 
 Volume    50 
6Author    M. Grottel, M. Szafrański, Z. PająkRequires cookie*
 Title    NMR Study of Cation Motion in Guanidinium Iodoplumbates  
 Abstract    Proton NMR second moments and spin-lattice relaxation times of polycrystalline C(NH 2) 3 PbI 3 and [C(NH 2) 3 ]2PbI 4 were studied in a wide temperature range. The order-disorder character of the existing solid-solid phase transitions was confirmed and for tetraiodoplumbate a new phase transition at 170 K was discovered. For both compounds a dynamical inequivalence and unusual high mobility of the guanidinium cations were revealed. For the reorientations discovered (NH 2 group flipping, C 3 in-plane reorientation and a tumbling) the activation parameters were determined. 
  Reference    Z. Naturforsch. 52a, 783—788 (1997); received October 6 1997 
  Published    1997 
  Keywords    NMR, Molecular Motions, Phase Transitions 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/52/ZNA-1997-52a-0783.pdf 
 Identifier    ZNA-1997-52a-0783 
 Volume    52 
7Author    PhilipJ. Bray, GaryL. PetersenRequires cookie*
 Title    NMR and NQR Studies of Borate Glasses  
 Abstract    Nuclear magnetic resonance (NMR) has been used for some 40 years to study atomic arrange-ments, chemical bonding, and structural groupings in borate glasses and crystalline compounds, and nuclear quadrupole resonance (NQR) has more recently increased the resolution and accuracy of the measurements. Examples are presented of the use of first-order and second-order quadrupo-lar effects in "B NMR spectra to obtain structural information, and n B and 10 B NQR spectra to obtain the quadrupolar parameters Q cc (the coupling constant) and 77 (the asymmetry parameter) with accuracies of 5 or 6 significant figures, and 3 figures, respectively. Q cc and 77 are extremely sensitive to changes in atomic rearrangements and chemical bonds, so they are excellent monitors and provide identification of bonding configurations and structural groupings in borates: Examples are also presented in which combinations of NMR and NQR data are used to extract the desired information. NQR detection of resonances at frequencies as low as 276 kHz is discussed. 
  Reference    Z. Naturforsch. 53a, 273—284 (1998); received December 30 1997 
  Published    1998 
  Keywords    NMR, NQR, Borates, Quadrupolar Interactions 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0273.pdf 
 Identifier    ZNA-1998-53a-0273 
 Volume    53 
8Author    Maria Zdanowska-Fnjczek, Malgorzata Grottel, Ryszard JakubasRequires cookie*
 Title    C1 NQR and l H NMR Studies of Molecular Motions in Guanidinium Salt of Chloroacetic Acid  
 Abstract    Multinuclear NQR and NMR techniques have been applied in order to study the molecular dynamics in [C(NH 2) 3 ](ClH 2 CCOO). The 35 C1 NQR frequency was measured over a wide range of temperature. The experimental results were described by using the theories of Bayer and Brown which take into account the torsional oscillations of the CClH 2 -group of the anion. A study of the proton NMR second moment as well as relaxation times T, and T Xp performed in a wide temperature range revealed an onset of the guanidinium cation reorientation around its two-fold symmetry axis. Activation parameters for this motion were determined. 
  Reference    Z. Naturforsch. 53a, 484—487 (1998); received March 24 1998 
  Published    1998 
  Keywords    NMR, NQR, Molecular Motion 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0484.pdf 
 Identifier    ZNA-1998-53a-0484 
 Volume    53 
9Author    A. Pajzderska, J. Wąsicki, S. LewickiRequires cookie*
 Title    Molecular Motion in Tetraphenyltin Studied by NMR  
 Abstract    NMR second moment and spin-lattice relaxation times in the laboratory (60 and 25 MHz) and in the rotating frame (B { = 2.1 mT) were studied for polycrystalline tetraphenyltin Sn(C 6 H 5) 4 in a wide tem-perature range. Two kinds of motions were detected: isotropic rotation of whole molecules and reorien-tations/oscillations of phenyl rings. A dependence of the potential energy of the molecule in the crystal on the angle of the phenyl ring rotation about the Sn-C bond was obtained on the basis of atom-atom calculations. The amplitude of the ring-oscillations at 133 K was estimated as ± 7°. Below room tem-perature the magnetisation recovery is significantly non-exponential, which may be interpreted as due to the correlated motion of phenyl rings. 
  Reference    Z. Naturforsch. 54a, 488—494 (1999); received June 7 1999 
  Published    1999 
  Keywords    NMR, Relaxation, Potential Energy 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/54/ZNA-1999-54a-0488.pdf 
 Identifier    ZNA-1999-54a-0488 
 Volume    54 
10Author    T. J. BastowRequires cookie*
 Title    47,49jj NMR in Metals, Inorganics, and Gels  
 Abstract    Some recent progress in solid state 47,49 Ti NMR is described and reviewed. The metallic-state work described covers metals such as hep titanium, TiB 2 , a number of intermetallics such as TiAl 2 and TiAl 3 . The inorganic work covers the various titanium oxide based materials including the Ti0 2 polymorphs, anatase, rutile and brookite. The gel work covers the evolution of crystalline titania from gels formed by hydrolysis of titanium isopropoxide. Some complementary data from 17 0 and 13 C NMR and powder X-ray diffraction is also included. 
  Reference    Z. Naturforsch. 55a, 291—297 (2000); received September 11 1999 
  Published    2000 
  Keywords    Titanium, NMR, Metals, Oxides, Gels 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0291.pdf 
 Identifier    ZNA-2000-55a-0291 
 Volume    55 
11Author    Liuping Chen, Thomas Gross, Hans-Dietrich LüdemannRequires cookie*
 Title    The T, /7-Dependence of the Chemical Shift of the Hydroxyl Protons in Deeply Supercooled Methanol and Water  
 Abstract    The hydroxyl proton chemical shifts 6 (H-O) of supercooled methanol (7" min = 149 K) and water have been determined (7" min = 183 K), and the pressure dependence of these shifts was measured up to 200 MPa. In both compounds the downfield shift of <5 (H-O) continues down to the lowest tempera-tures reached. This result disagrees with the two state models for the hydrogen bond formation in both liquids. The isotherms ö (H 2 0) show for T< 273 K an upfield shift that becomes more pronounced with decreasing temperature. For 6 (H-O-CH^), increasingp causes at all temperatures a downshift. 
  Reference    Z. Naturforsch. 55a, 473—477 (2000); received November 11 1999 
  Published    2000 
  Keywords    NMR, Supercooling, Pressure, Methanol, Water 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0473.pdf 
 Identifier    ZNA-2000-55a-0473 
 Volume    55 
12Author    Kurt MoedritzerRequires cookie*
 Title    -Chloro-and l-Hydroxyphospholene-l-stilfides l-Chlorophospholene-l-sulfi.de Isomers, 1-Hydroxyphospholene-l-sulfide Isomers  
 Abstract    A mixture of the two isomers of 1-chlorophospholene-l-oxide, obtained by a one-step, high-yield procedure reported previously 1 , upon reaction with P4S10 was converted to a mixture of the two isomers of 1-chlorophospholene-l-sulfide which may be separated by spinning-band distillation. The thus obtained isomerically pure 1-chlorophospholene-1-sulfides were hydrolyzed to the corresponding 1-hydroxyphospholene-l-sulfides. These, as well as the precursor chloro compounds, were characterized by iH, 13 C, and 31 P NMR, mass spectrometry, and IR. 
  Reference    (Z. Naturforsch. 31b, 709—713 [1976]; received January 20 1976) 
  Published    1976 
  Keywords    NMR, Mass Spectra, IR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/31/ZNB-1976-31b-0709.pdf 
 Identifier    ZNB-1976-31b-0709 
 Volume    31 
13Author    Fritz Seel, Fritz SchinnerlingRequires cookie*
 Title    Darstellung und thermische Zersetzung von Erdalkalimetall-Carbamoylphospliaten Preparation and Thermal Decomposition of Carbamoylphosphates of Alkaline-earth Metals  
 Abstract    After the formation of carbamoylphosphate through the reaction of KH2PO4 with KNCO in aqueous solution, unreacted phosphate and carbamoylphosphate can be separated by fractional precipitation with barium (first step) and calcium or strontium or barium salt solutions (second step) at low temperatures. The carbamoylphosphates of the alkaline earth metals are decomposed above 100 °C to yield predominantly diphosphates and urea. In aqueous suspensions the decomposition proceeds even at room temperature. -The chemical shifts of the phosphorus atom of the carbamoylphosphate ion between pH 6.5 and 8.2 are given. 
  Reference    Z. Naturforsch. 33b, 374—381 (1978); eingegangen am 31. Januar 1978 
  Published    1978 
  Keywords    Carbamoylphosphates, Preparation, Decomposition, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0374.pdf 
 Identifier    ZNB-1978-33b-0374 
 Volume    33 
14Author    Uwe KlingebielRequires cookie*
 Title    Reaktionen von Lithio-aminofluorsilanen mit Halogensilanen und Trimethylzinnchlorid Reactions of Lithio-aminofluorosilanes with Halogensilanes and Trimethyltinchloride  
 Abstract    Fluorosilanes react with lithium amides and organolithium compounds to give amino-fluorosilanes. (Lithioamino)fluorosilanes are formed by the reaction of aminofluoro-silanes with butyllithium depending on the steric influence and molecular stabilization of the ligands. These lithium salts react with halogensilanes and trimethyltin chloride with substitution. By LiF elimination the lithio-aminofluorosilane C6H5-SiF-NLiC(CH3)3-N(p-C6H4CH3Si(CH3)3) cyclisizes through a (2-j-2)cycloaddition and SiC-H-cleavage. 
  Reference    Z. Naturforsch. 33b, 521—526 (1978); eingegangen am 3. Januar/21. Februar 1978 
  Published    1978 
  Keywords    Lithio-aminofluorosilanes, Substitution, Cyclisation, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0521.pdf 
 Identifier    ZNB-1978-33b-0521 
 Volume    33 
15Author    Anton Meiler, Walter Maringgele, Klaus-Dieter Kablau, R3b @bullet, R. —n=c 'r, B. R. N=cRequires cookie*
 Title    Umsetzungen von Metall-und Metalloidverbindungen mit mehrfunktionellen Molekülen, XVIII [1] Synthese von Amidinoborazinen Reactions of Metal and Metalloid Compounds with Polyfunctional Molecules, XVIII [1] Synthesis of Amidinoborazines  
 Abstract    The reaction of trimethylsilylamidines with 2-chloro-l,3,4,5,6-pentamethylborazine leads to the corresponding amidinoborazines and chlorotrimethylsilane. 1 H, 11 B, n F NMR spectra, mass spectra and characteristic IR group frequencies are reported. Umsetzungen von Trialkylboranen mit Amidinen ergeben nach Die Si-N-Bindung wird durch Halogenborane meist unter milden Bedingungen nach 
  Reference    Z. Naturforsch. 33b, 891—895 (1978); eingegangen am 5. Mai 1978 
  Published    1978 
  Keywords    Chloroborazines, Silylamidines, Amidinoborazines, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0891.pdf 
 Identifier    ZNB-1978-33b-0891 
 Volume    33 
16Author    OttoJ. Scherer, Norbert Kuhn, Heribert JungmannRequires cookie*
 Title    Elementorganische Amin/Imin-Verbindungen, XIX [1] Phospha(III)azen-Komplexe des Platins Elementorganic Amino/Imino Compounds, XIX [1] Phospha(III)azene Complexes of Platinum  
 Abstract    Reacting Zeise's salt with the phospha(III)azene (R3C)(R3Si)N-P = N-CR3 (R = CH3) (1) one gets the platinum phospha(III)azene complex (2), Cl2PtI<2 (L = 1). 2 adds water and methanol to the P=N bond of the phospha(III)azene ligand with formation of 3, Cl2Pt(PRR2 1)2 (R = (CH3)3SiO, R 1 = (CH3)3CNH) and 4, Cl2Pt(PRR 1 R 2)2 (R = CH30, R 1 = (CH3)3CNH, R2 = (CH3)3SiNC(CH3)3). 2, 3 and 4 have trans configuration, 4 also forms a mixture of the meso and d, 1 isomers. For 2 a P-a coordination of the phospha(III)-azene ligand is proposed. Die inzwischen in größerer Anzahl bekanntge-wordenen Phospha(III)azene des Typs A [la] /Py -W X N-A I 
  Reference    Z. Naturforsch. 33b, 1321—1324 (1978); eingegangen am 12. Juli 1978 
  Published    1978 
  Keywords    Synthesis, Addition Reactions, Diastereoisomers, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-1321.pdf 
 Identifier    ZNB-1978-33b-1321 
 Volume    33 
17Author    HansH. KarschRequires cookie*
 Title    Funktionelle Trimethylphosphinderivate, VIII [1] Phosphoniumsalze, Oxide und Sulfide von Tetraorganodiphosphinomethanen, R2PCH2P(CH3)2  
 Abstract    Tetramethyldiphosphinomethane (CH3)2PCH2(CH3)2 (la) reacts with HCl/ether to form the mono-and bisquaternary salts [(CH3)2PCH2P(H)(CH3)2]C1 (2) and [(CH3)2(H)PCH2P(H)(CH3)2]Cl2 (3), respectively. The system 1 a/HCl, incorporating 1 a/2/3, represents a useful tool for studying the appearance of XnAA'X'n-spin type systems. These compounds are also prototypes for a variety of other mono-or bis-phosphonium salts, which are formed in the reactions of the diphosphines (CH3)2PCH2PR2 (R — CH3, *-C4H9, C6H5) (la-c) with (CH3)2C0 + HC1, CH3I, *-C4H9Br, C6H5C0C1, (CH3)2PC1 and Br(CH2)nBr (n = 1, 2). Heterocycles are not obtained. The dioxide 14 and the disulfide 15 are also described. Some properties and spectroscopic data (IR, 1 H, 31 P and 13 C NMR) of 26 new compounds are reported and briefly discussed. 
  Reference    (Z. Naturforsch. 34b, 31—43 [1979]; eingegangen am 8. September 1978) 
  Published    1979 
  Keywords    Phosphonium Salts, Oxides, Sulfides, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0031.pdf 
 Identifier    ZNB-1979-34b-0031 
 Volume    34 
18Author    Wolfgang BuderRequires cookie*
 Title    Darstellung und spektroskopische Untersuchung von Trimethoxysilylpropylsulfanen Synthesis and Spectroscopy of Silylsulfanes  
 Abstract    The preparation of the sulfanes [(CH30)3Si-(CH2)2-]2Sra (n = 1-4) 2-5 and the cor-responding mercaptane 1 is communicated. The *H and 13 C NMR spectra of 1-5 are reported and discussed. The infrared and Raman spectra are discussed in view of C-S-and S-S-bonding. 
  Reference    Z. Naturforsch. 34b, 790—793 (1979); eingegangen am 21. Dezember 1978/16. März 1979 
  Published    1979 
  Keywords    Silylsulfanes, Mercaptane, IR, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0790.pdf 
 Identifier    ZNB-1979-34b-0790 
 Volume    34 
19Author    Gert Bauer, Gerhard Hagele, Peter SartoriRequires cookie*
 Title    Reaktionen polyhalogenierter Cyclobutane mit Trimethylphosphit Reactions of Polyhalogenated Cyclobutenes with Trimethylphosphite  
 Abstract    Polyhalogenated cyclobutanes are synthesized and dehalogenated to cyclobutenes bv means of trimethylphosphite. Im Zusammenhang mit unseren Untersuchungen über die Arbuzov-Reaktion polyhalogenierter Cyclo-butene [1-3] wandten wir uns der Darstellung und Dehalogenierung von Cyclobutanderivaten zu. In diesem Zusammenhang studierten wir auch die Um-setzungen von C4ClnFg_n (n = 2-5), C4Hn Br2F6-n (n = 0 und 1) und C4H2CI3F3 mit Trimethylphosphit. Während die höherfluorierten Cyclobutane GiClnFs-n {n = 2-4) und auch C4H2CI3F3 bekanntlich durch Auto-bzw. Co-Cycloadditionsreaktionen zu-gänglich sind [4-14], bleibt dieser Weg für das 1.1.2-Trifluorpentachlorcyclobutan C4CI5F3 ver-schlossen. Wir erhielten die gesuchte Verbindung erstmalig durch UV-aktivierte Photochlorierung ge-mäß: F H F \ Cl; • <V-2 HCl F Cl F \ Cl, F \ H UV/120' C/30h /f \ Cl m ci ci Cl Cl 1a als farblose, sublimierbare Substanz vom Schmp. 105,5 °C mit einer Ausbeute von 46%. 1.2-Dibromhexafluorcyclobutan C4Br2F6 kann prinzipiell durch Cycloaddition von CF2=CFBr ge-wonnen werden [4]. Hier stellten wir die gewünschte Verbindung aber vorteilhafter durch lichtaktivierte Addition von elementarem Brom an Hexafluor-cyclobuten mit 96-proz. Ausbeute dar [15]. Im Gegensatz zur Cycloaddition führt die Bromierung nicht zu einem Gemisch der cis/trans-Isomeren, sondern lediglich zu einem der beiden isomeren C4Br2F6. Wir vermuten, daß es sich hierbei um die Transform handelt und wollen dies künftig aus * Sonderdruckanforderungen an Prof. Dr. Gerhard Hägele. 0340-5087/79/9000-1249/$ 01.00/0 der expliziten Spektralanalyse entsprechender [ABC]2-19 F-NMR-Spektren ableiten. Eine analog [16] durchgeführte Bromierung von 1-H-pentafluorcyclobuten verläuft dagegen nicht stereospezifisch. Hier fanden wir eis-und trans-CiHB^Fö im molaren Verhältnis 1:4 mit einer Gesamtausbeute von 60% vor. Die von uns ge-troffene Zuordnung der Isomeren beruht auf einer vollständigen, iterativen Analyse von ABCDEX-Spektren, deren Ergebnisse im experimentellen Teil der vorliegenden Arbeit wiedergegeben sind. Bei unseren Versuchen polyhalogenierte Cyclo-butane mit Trimethylphosphit zur Reaktion zu bringen interessierte uns die Fragestellung, ob die Bildung von Cyclobutan-substituierten Phosphon-säuredimethylester durch Arbuzov-Reaktionen nachgewiesen werden kann, etwa nach: ^ Ä ^ (2) P(0)(0CHJ)S Unter den hier gewählten Bedingungen bilden die Cyclobutane mit Sicherheit keine Phosphonsäure-ester. Es war ferner von Interesse festzustellen, ob die dehalogenierende Wirkung des Trimethylphosphits [17] zur Abspaltung von H-X oder F-X (X = F, Cl, Br) aus den gemischt-halogenierten Cyclobutan-abkömmlingen synthetisch ausgenutzt werden kann. Unsere Versuche zeigten, daß unter relativ milden Bedingungen praktisch nur X-X (X = Cl, Br) durch Trimethylphosphit abspaltbar ist. Es werden Cyclo-butene gebildet nach: S. % S3 \ Ay P(0CHJ)J Sj \ X -CHsX/' tCHj OfePtOl X S< X S, * ^ S2 ^S, (3) 1250 G. Bauer-G. Hagele • Reaktionen polyhalogenierter Cyclobutene mit Trimethylphosphit 1250 Hierbei werden die Bromderivate C4H"Br2F6_n (n = 0 und 1) besonders rasch zu C4HnF6_n {n = 0 und 1) debromiert. In der Serie der Chlor-Fluor-Cyclobutane C4ClnF8_n (n = 3-5) nimmt die Reakti-vität auffallend zu mit wachsendem Chlorgehalt. Man erhält die Cyclobutene C4Cln_2F8_n {n = 3-5). C4CI2F6 und C4H2CI3F3 verhalten sich dahingegen inert. Es sei erwähnt, daß das aus C4CI3F5 entstandene 1-Chlorpentafluorcyclobuten C4CIF5 in situ mit wei-terem Trimethylphosphit zu einem Phosphoran reagiert [1] gemäß: (4) n H ^PfFKOCH), F F X= Cl Das Verhalten polyhalogenierter Cyclobutene unter den Bedingungen der Arbuzov-Reaktion behandeln wir systematisch in der nachfolgenden Arbeit [1]. Tab. I stellt die Ergebnisse unserer nach Gl. (3) intendierten Versuche übersichtlich dar: Tab. I. Umsetzung polyhalogenierter Cyclobutane mit Trimethylphosphit. Edukt Reaktion Aus-beute [%] Produkt (la) C4CI5F3 (lb) C4CI4F4 (lc) C4CI3F5 (ld) C4C12F6 (le) C4Br2F6 stark exotherm 90 stark exotherm 90 schwach exotherm * keine Reaktion — stark exotherm 70 90 C4CI3F3 (2 a) C4C12F4 (2b) C4CIF5 (2 c) (1 f) C4HBr2F5 stark exotherm (lg) C4H2C13F3 keine Reaktion C4F6 C4F5H (2e) (21) 
  Reference    Z. Naturforsch. 34b, 1249—1251 (1979); eingegangen am 3. April/10. Mai 1979 
  Published    1979 
  Keywords    Dehalogenation, Cyclobutanes, Photochlorination, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-1249.pdf 
 Identifier    ZNB-1979-34b-1249 
 Volume    34 
20Author    V. P. Tarasov, V. I. Privalov, G. A. Kirakosyan, YuA. BuslaevRequires cookie*
 Title    Scalar Second-Kind Relaxation of 27 A1, 69 Ga and 71 Ga Nuclei in Aluminium and Gallium Complexes  
 Abstract    Spin-spin and spin-lattice relaxation times of nuclei 69 > 71 Ga, 27 A1, 14 N in anions [MClnBr4_n]-and the solvate complexes [M(CH3CN)6] 3+ , produced from dissolution of MCI3 and MBr3 in the mixture CH3CN + CH3N02 (M = Ga, Al), are measured in the temperature range from —40 up to + 70 °C. It is shown that nuclear spins of 69 > 71 Ga, 27 A1 relax in the anionic and cationic complexes by means of the second-kind scalar and quadrupole relaxation mechanisms (due to the relaxation of the nuclei 35 ' 37 C1, 79 ' 81 Br, 14 N). The complexes [MClwBr4_n]-and [M(CH3CN)6] 3+ in the investigated solutions are inert and do not undergo exchange processes in the NMR time scale. The scalar spin coupling constants in [M(CH3CN)6] 3+ are determined from the scalar contribution to the relaxation rate of 69 -71 Ga, 27 A1, and the measured relaxation time of 14 N in the solvate complex; the results are Ga-14 N) -59 ± 5 Hz, J(71 Ga-14 N) = 74 ± 6 Hz, J(27 Al-i 4 N) = 22 ± 2 Hz. 
  Reference    Z. Naturforsch. 38b, 1173—1181 (1983); received May 3 1983 
  Published    1983 
  Keywords    Aluminium, Gallium, Relaxation, NMR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1173.pdf 
 Identifier    ZNB-1983-38b-1173 
 Volume    38 
1
2
3
4
5
Next
Disclaimer   ★    Pivacy Policy   ★    Contact

Creative Commons License