Nuclear Magnetic Resonance Spectra of the [AXn]3Spin System. Part II.19F NMR Spectra offac-Trisubstituted Fluorophosphine Molybdenum Complexes

1971 ◽  
Vol 75 (2) ◽  
pp. 134-140 ◽  
Author(s):  
R. K. Harris ◽  
J. R. Woplin ◽  
R. Schmutzler

1983 ◽  
Vol 61 (8) ◽  
pp. 1795-1799 ◽  
Author(s):  
Philip A. W. Dean

The previously reported 1:1 complexes formed in MeNO2, between M(SbF6)2 (M = Sn or Pb) and Ph2P(CH2)2PPh2, PhP[(CH2)2PPh2]2, MeC(CH2PPh2)3, P[(CH2)2PPh2]3, and [Formula: see text] have been studied by metal (119Sn or 207Pb) nmr. The metal chemical shifts span the comparatively narrow range of −586 to −792 ppm and 60 to −269 ppm, relative to the resonance of MMe4, for 119Sn and 207Pb nmr, respectively. The implications of these data regarding the denticity of the ligand in M(P[(CH2)2PPh2]3)2+ are discussed, and a comparison with the metal nmr spectra of related stannous and plumbous complexes is made.



1979 ◽  
Vol 57 (3) ◽  
pp. 318-319 ◽  
Author(s):  
Mark A. Johnson ◽  
Michael P. Fleming

It is unequivocally shown that the published nmr spectra assigned to 2-endo,3-exo-camphanediol and 2-exo-3-endo-camphanediol should be reversed. The 2-exo,3-endo isomer is prepared unambiguously by hydroboration–oxidation of camphor enol silyl ether.



1979 ◽  
Vol 57 (23) ◽  
pp. 3168-3170 ◽  
Author(s):  
Henk Hiemstra ◽  
Hendrik A. Houwing ◽  
Okko Possel ◽  
Albert M. van Leusen

The 13C nmr spectra of oxazole and eight mono- and disubstituted derivatives have been analyzed with regard to the chemical shifts and the various carbon–proton coupling constants of the ring carbons. The data of the parent oxazole are compared with thiazole and 1-methylimidazole.



1979 ◽  
Vol 34 (8) ◽  
pp. 1078-1083 ◽  
Author(s):  
Ralf Janda ◽  
Gert Heller

The 11B nuclear magnetic resonance spectra of sodium, potassium and ammonium polyborates in aqueous solutions, - as a function of concentration and pH - , provide information of the hydrolysis equilibria. Two 11B NMR lines are observed in aqueous solutions of Na[B5O6(OH)4], K[B5O6(OH)4] and NH4[B5O6(OH)4]. Only one 11B NMR line is recorded in aqueous solutions of (NH4)2[B4O5(OH)4] and Na2[B4O5(OH)4]. The results of the 11B NMR spectra are discussed and compared with the results obtained from Raman studies of aqueous polyborate solutions



1980 ◽  
Vol 58 (23) ◽  
pp. 2588-2591 ◽  
Author(s):  
Guy G. S. Dutton ◽  
Angela V. Savage ◽  
Michel Vignon

A β-D-galactosidase associated with bacteriophage [Formula: see text] has been used to depolymerize the capsular polysaccharide of Klebsiella serotype K18 into the hexasaccharide corresponding to one repeating unit of the polymer. The nmr spectra of the polymer and of the oligosaccharide are comparable, leading to the conclusion that the conformations in solution of the repeating unit of the two substances are similar.



1979 ◽  
Vol 57 (13) ◽  
pp. 1652-1655 ◽  
Author(s):  
S. William Pelletier ◽  
Naresh V. Mody ◽  
Rajinder S. Sawhney

The natural abundance carbon-13 nuclear magnetic resonance spectra of some C19-diterpenoid alkaloids and their alkamines (lappaconitine, lappaconine, lapaconidine, ranaconine, 14-dehydrobrowniine, aconine, pseudoaconine, deoxyaconine, and hypaconine) have been determined at 15.03 MHz. With the aid of proton decoupling techniques, additivity relationships, and comparison with spectra of related alkaloids, self-consistent and unambiguous assignments of nearly all carbon resonances for these alkaloids have been made. Some important chemical shift trends have been observed, which are useful for identifying the basic C19-diterpenoid alkaloid skeleton and the hydroxy and methoxy group substitution patterns in these alkaloids. On the basis of 13C nmr spectra of lappaconitine and lappaconine, the anthranoyl ester moiety is assigned to the C-4 position in lappaconitine. The 13C nmr spectra of lapaconidine, aconine, and pseudoaconine taken in pyridine and chloroform have been compared to determine the conformational changes of the ring A hydroxy groups in these alkaloids.



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