Go toArchive
Browse byFacets
Bookbag ( 0 )
'n B NMR Spectra' in keywords
Results  7 Items
Sorted by   
Section
Publication Year
1997 (1)
1996 (3)
1981 (1)
1980 (2)
1Author    Rosalinda Contreras, Bernd WrackmeyerRequires cookie*
 Title    Anwendung der 11 B-NMR-Spektroskopie zur Untersuchung von Hydroborierungen, I Hydroborierung von 3-Methyl-1.3-butadien mit Boran in Tetrahydrofuran und Dimethylsulfid Application of n B NMR Spectroscopy to the Study of Hydroboration, I Hydroboration of 3-Methyl-l,3-butadiene with Borane in Tetrahydrofurane and Dimethyl Sulfide  
 Abstract    The intermediacy of 3-methyl-l-boracyclopentane in the hydroboration of 3-methyl-1,3-butadiene with borane in tetrahydrofurane (BH3-THF) and dimethyl sulfide (BH3-DMS) has been established by means of n B NMR spectroscopy. The reaction proceeds through the trialkylborane stage (3:2 products) and the latter undergo exchange reactions with boron hydrogen compounds present. This has been proved independently by studying the n B NMR spectra of the mixtures between the 3:2 products and BH3-THF and BH3-DMS, respectively. Evidence is provided that opening of the boracyclopentane ring in exchange reactions is accompanied by exocyclic exchange. These results are further confirmed by the n B NMR spectra of the mixtures between l-phenyl-3-methyl-l-boracyclopentane and BH3-THF and BH3-DMS, respectively. U B NMR spectra of the 3:2 products dissolved in DMS allow evaluation of the isomer distribution. 
  Reference    Z. Naturforsch. 35b, 1229—1235 (1980); eingegangen am 13. Juni 1980 
  Published    1980 
  Keywords    Hydroboration, Exchange Reactions, n B NMR Spectra 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-1229.pdf 
 Identifier    ZNB-1980-35b-1229 
 Volume    35 
2Author    Werner Biffar, Heinrich NöthRequires cookie*
 Title    Beiträge zur Chemie des Bors  
 Abstract    , 124 [1] Tris(trimethylsilyl)silyl-borane und Tris(trimethylsilyl)silyl-borate Contributions to the Chemistry of Boron, 124 [1] Tris(trimethylsilyl)silyl Boranes and Tris(trimethylsilyl)silyl Borates The reactions of several boron halides, methoxides, alkyls and hydrides with tris(tri-methylsilyl)silyllithium, which was isolated as the solvate [(CH3)3Si]3SiLi • SCtHsO, 1 (TMSSLi) have been studied. (CH 3)2B-Si[Si(CH 3) 3 ]3 and 9-[(CH 3)3Si] 3 Si-9-BBN, were isolated, while [(CH 3)3Si]3Si-B(«C4H 9)2 could only be detected by n B NMR. In addition TMSS-B[N(CH 3) 2 ]2, (TMSS) 2 BNMe 2 and (TMSS) 2 BOCH 3 were prepared. The methoxy-boranes (CHs)3_ n B(OCHa) n add to 1 forming silylborates; however, no OCH3/Si[Si(CH3)3]3 substitution occurs. The hydrogen bridge in 9-BBN is cleaved symmetrically. The results can be explained by the basicity and the steric requirements of the TMSS group. The TMSS group exhibits a deshielding effect at the boron nucleus relative to the (CH3)3Si group for silylboranes as well as for silylborates. 
  Reference    Z. Naturforsch. 36b, 1509—1515 (1981); eingegangen am 3. Juli 1981 
  Published    1981 
  Keywords    Silylboranes, Silylborates, Steric effects, n B NMR Spectra 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1509.pdf 
 Identifier    ZNB-1981-36b-1509 
 Volume    36 
3Author    Richard Goetze, Heinrich NöthRequires cookie*
 Title    Zur Kenntnis von 1.3.2-Dithiaborolen [2] Contributions to the Chemistry of Boron, 112 [1] 1,3,2-Dithiaboroles [2]  
 Abstract    Several methods were used to prepare a series of boron substituted 1,3,2-dithiaborols. The NMR data of this new class of compounds indicate in comparison to 1,3,2-dithia-borolanes, that the heterocycle can be looked at as a 6 jt-electron system. A high degree of analogy in the mass spectrometric fragmentation of dithiaborolanes and dithiaborols exists, however, the parent ion of 2-methyl dithiaborol is more stable than that of the saturated analogon. 
  Reference    Z. Naturforsch. 35b, 1212—1221 (1980); eingegangen am 30. Januar 1980 
  Published    1980 
  Keywords    1, 3, 2 -Dithiaboroles, n B NMR Spectra, 13 C NMR Spectra 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-1212.pdf 
 Identifier    ZNB-1980-35b-1212 
 Volume    35 
4Author    D. Bublitz, A. Franken, W. Preetz, H. ThomsenRequires cookie*
 Title    Darstellung, U B-NMR-Spektren, Schwingungsspektren und Normalkoordi- natenanalyse von cowy'HWcto-Bis-hexahydro-c/oso-hexaborat, [B6H6-B 6H6]2_, sowie Kristallstruktur von [P(C6H5)4 ]2-cöW7 ww^o-[B6H6-B 6H6 ] Preparation, 11B NMR Spectra, Vibrational Spectra and Normal Coordinate Analysis of con ju ncto-B is-h exah ydro-closo-h exaboratQ , [B6H6-B 6H6]2_, and the Crystal Structure of [ P(C6 H5 )4 ] 2 -conjuncto-[B6 H6-B 6 H6 ]  
 Abstract    By reaction of [B6H6]2-with dibenzoylperoxide in dichloromethane conjuncto-[B6H6-b 6h 6]2-is formed. The product could be separated from excess [B6H6]2 by ion exchange chro­ matography on diethylaminoethyl cellulose. The crystal structure of [P(C6H^ ^ -con ju n cto-[B6H6-B 6H6 ] has been determined by single crystal X-ray diffraction analysis; triclinic, space group PI with a = 10.8315(10), b = 11,2422(12), c = 20.340(2) Ä, a = 91.278° (9), ß = 9 0 .\78° (9), 7 = 105.662°(9). The 1 'B NMR spectrum reveals three signals with the intensity ratio 1:1:4, for two equivalent moieties of the conjuncto molecule ion with local C4v symmetry. The IR and Raman spectra of the deprotonated Cs salts of the 1()B, n B and their respective D isotopomers of conjuncto-[B6H5-B6HS]4_ exhibit characteristic shifts. Using averaged crystallographic data and assuming idealized D4h symmetry, normal coordinate analyses have been performed based on a modified valence force field. With a set of eleven force constants (e.g. fd(BB)C 0njU IK.t0 = 2.9, fd(BB)cage = 1.6 mdyn/A) very good agreement between observed and calculated frequencies has been achieved. From strong vibrational coupling with the B6 clusters two vibrations result for the conjuncto B-B bond at 1142/1198 and 292/304cm-1 for 1 'B/I(IB species, respectively. They can be assigned as anti-phase and in-phase motions of the conjuncto B atoms related to the equatorial B4 planes. 
  Reference    Z. Naturforsch. 51b, 609—618 (1996); eingegangen am 7. September 1995 
  Published    1996 
  Keywords    Crystal Structure, n B NMR Spectra, Vibra­ tional Spectra, Normal Coordinate Analysis 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-0609_n.pdf 
 Identifier    ZNB-1996-51b-0609_n 
 Volume    51 
5Author    ]. C. Nachtigal, W. PreetzRequires cookie*
 Title    Darstellung, n B-NMR  
 Abstract    , Schwingungsspektren und Kristallstruktur von Bis(tetraphenylphosphonium)-2-[2-(2-pyridyl-amino)-pyrid-5-yl]-c/oso-decaborat, [P(C6H5)4]2[2-{2-(2-(C5H4N)-NH)-(C5H3N)-5}B10H9] Preparation, 11B NMR, Vibrational Sprectra and Crystal Structure of Bis(tetraphenylphosphonium) 2-[2-(2-Pyridyl-amino)-pyrid-5-yl]-c/fxw-decaborate, [P(C6H5)4]2 [2 2-[2-(2-Pyridyl-am ino)-pyrid-5 -yl]-c7r« 0-decaborate( 
  Reference    Z. Naturforsch. 51b, 1559—1562 (1996); eingegangen am 29. Mai 1996 
  Published    1996 
  Keywords    ), Crystal Structure, n B NMR Spectra, Vibrational Spectra 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-1559.pdf 
 Identifier    ZNB-1996-51b-1559 
 Volume    51 
6Author    W. Lübbe, W. PreetzRequires cookie*
 Title    Darstellung, n B-, 13C-, !H-NMR-und Schwingungsspektren von //-Methylen-bis  
 Abstract    hexahydro-c/öso-hexaborat, [B6H6(CH2)B6H6]2_, und Kristallstruktur von [As(C6H5)4]2[B6H6(CH2)B6H6]* V2(CH3)2CO Preparation, "B , 13C, NM R and Vibrational Spectra of //-M ethylene-bis-hexahydro-doso-hexaborate, [B6H 6(C H 2)B6H 6]2~, and Crystal Structure of [As(C6H 5)4]2[B6H 6(C H 2)B6H 6] • V2 (CH3)2CO ^-M ethylene-bis-hexahydro-c/oso-hexaborate(2-), ' 
  Reference    Z. Naturforsch. 51b, 545 (1996); eingegangen am 19. Septem ber 1995 
  Published    1996 
  Keywords    H NM R Spectra, Vibrational Spectra, 13C NMR Spectra, n B NMR Spectra 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-0545.pdf 
 Identifier    ZNB-1996-51b-0545 
 Volume    51 
7Author    T. Koch, W. PreetzRequires cookie*
 Title    Darstellung, n B-, 13C -,1 H-NMR-und Schwingungsspektren  
 Abstract    von 2,2' -Bipyridylundecahydro-c/oso-dodecaborat(1-) sowie Kristallstruktur von (Ph4As)[(2,2-C10H8N2)B12Hn ] CH3CN Synthesis, n B, 13C, 'H NMR and Vibrational Spectra of 2 ,2 '-Bipyridyl-undecahydro-c/o5o-dodecaborate(l-) and Crystal Structure of (Ph4As)[(2 ,2 '-C10H8N2)B 12H 1 1 ]-CH3CN 
  Reference    Z. Naturforsch. 52b, 1165—1168 (1997); eingegangen am 17. Juli 1997 
  Published    1997 
  Keywords    2, 2'-Bipyridyl-undecahydro-c/oso-dodecaborate(l-), Crystal Structure, n B NMR Spectra, 1H NMR Spectra, 13C NMR Spectra, Vibrational Spectra 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/52/ZNB-1997-52b-1165.pdf 
 Identifier    ZNB-1997-52b-1165 
 Volume    52