scholarly journals Beiträge zur Chemie des Phosphors, 132 [1]. 31P-Kernresonanzspektrum und Struktur von Trimethylheptaphosphan(3), P7Me3 / Contributions to the Chemistry of Phosphorus, 132 [1]. 31P NMR Spectrum and Structure of Trimethylheptaphosphane(3), P7Me3

1983 ◽  
Vol 38 (8) ◽  
pp. 955-960 ◽  
Author(s):  
Marianne Bäudler ◽  
Thomas Pontzen
Keyword(s):  
31P Nmr ◽  
Chemical Shifts ◽  
Experimental Spectrum ◽  
Complete Analysis ◽  
Methyl Groups ◽  
Nmr Spectrum ◽  
H Nmr

Trimethylheptaphosphane(3) (1) was proved to possess the earlier reported structure of a 3,5,7-triorganotrieyclo[2.2.1.02,6] heptaphosphane [3] by complete analysis of its 31P{1H} NMR spectrum. The experimental spectrum can be simulated very satisfactorily by the superposition of the spectra of two isomers P7Me3sym and P7Me3 asym, differing from each other in the orientation of the methyl groups. A comparison of the chemical shifts with those of (Me3Si)3P7 and Li3P7 leads to a detailed information about the geometry of the P7-skeleton in both isomers of 1.

Beiträge zur Chemie des Phosphors, 147 [1] 31P-Kernresonanzspektrum und Struktur von Hexaethyl-octaphosphan(6), P8Et6 / Contributions to the Chemistry of Phosphorus, 147 [1] 31P NMR Spectrum and Structure of Hexaethyloctaphosphane(6), P8Et6

1984 ◽  
Vol 39 (12) ◽  
pp. 1671-1675 ◽  
Author(s):  
Marianne Bäudler ◽  
Eberhard Därr ◽  
Gerhard Binsch ◽  
David S. Stephenson
Keyword(s):  
31P Nmr ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Configuration And Conformation

Hexaethyloctaphosphane(6) (1) was proven to possess the structure of a 2,3,4,6,7,8-hexaethylbicyclo[3.3.0]octaphosphane by a complete analysis of its 31P {1H } NMR spectrum. The chemical shifts and coupling constants yielded inform ation about the configuration and conformation of 1.

scholarly journals Beiträge zur Chemie des Phosphors, 96 [1] Darstellung und 31P-Kernresonanzspektrum von isotopen-substituiertem Trilithium-heptaphosphid, 6Li3P7 / Contributions to the Chemistry of Phosphorus, 96 [1] Preparation and 31P NMR Spectrum of Isotopicly Substituted Trilithiumheptaphosphide, 6Li3P7

1980 ◽  
Vol 35 (5) ◽  
pp. 517-521 ◽  
Author(s):  
Marianne Baudler ◽  
Thomas Pontzen ◽  
Josef Hahn ◽  
Hans Ternberger ◽  
Wolfgang Faber
Keyword(s):  
Room Temperature ◽  
31P Nmr ◽  
Chemical Shifts ◽  
Exchange Process ◽  
Complete Analysis ◽  
Ionic Character ◽  
Line Broadening ◽  
Threefold Axis ◽  
Nmr Spectrum ◽  
Li Isotope

Abstract The P7-skeleton of trilithiumheptaphosphide, Li3P7 (1), was proved to possess the earlier reported tricyclic structure [2] by complete analysis of the 31P NMR spectrum of 6Li3P7 observed at - 60 °C. The 6Li isotopic substitution was carried out to avoid the line broadening caused by the large quadrupole moment of the 7Li isotope. The unambiguous elucidation of the Li3P7 structure confirmed that the exchange process which causes all P atoms to become equivalent above room temperature is analogous to that in bullvalene. A comparison of the chemical shifts with those of (Me3Si)3P7 leads to the result that the P7-skeleton in Li3P7 is noticeably compressed along its threefold axis, thus indicating a predominant ionic character.

Beiträge zur Chemie des Phosphors, 161 [1] Kernresonanzspektren und Struktur von Heptaphosphan(3), P7H3 / Contributions to the Chemistry of Phosphorus, 161 [1] NMR Spectra and Structure of Heptaphosphane(3), P7H3

1985 ◽  
Vol 40 (11) ◽  
pp. 1424-1429 ◽  
Author(s):  
Marianne Bäudler ◽  
Renate Riekehof-Böhmer
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spatial Arrangement ◽  
Complete Analysis ◽  
Hydrogen Atoms ◽  
Nmr Spectrum ◽  
H Nmr

Heptaphosphane(3) (1) is obtained pure by the reaction of (Me3Si)3P7 with methanol and has been characterized NMR spectroscopically (in nascent state). It turned out to be a mixture of two diastereomers P7H3sym and P7H3asym, which differ in the spatial arrangement of the hydrogen atoms. Both isomers were proven to possess the earlier reported structure of a tri-cyclo[2.2.1.02,6]heptaphosphane, which in the case of P7H3sym was ascertained by a complete analysis of its 31P{1H} NMR spectrum. As shown by the chemical shifts, the P7 cage in P7H3sym is clearly stretched compared with P7Me3sym and (Me3Si)3P7.

The assignment of 1H and 13C chemical shifts for dihydro-3(2H)-furanone derivatives by means of specific 2H labelling experiments and 13C{1H} decoupling experiments

1976 ◽  
Vol 54 (9) ◽  
pp. 1449-1453 ◽  
Author(s):  
Patrick M. Burke ◽  
William F. Reynolds ◽  
Janet C. L. Tam ◽  
Peter Yates
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Single Frequency ◽  
Methyl Groups ◽  
Similar Relationship ◽  
Chemical Shift Assignments ◽  
Lower Field ◽  
Nmr Spectrum ◽  
Methyl Proton ◽  
H Nmr

The 1H nmr spectrum of dihydro-2,2,5,5-tetramethyl-3(2H)-furanone (1) in 80% sulfuric acid shows a time-dependent decrease in the intensity of the lower-field gem-dimethyl signal relative to the upper-field gem-dimethyl signal. This is interpreted as involving reversible opening of 1 to 2-hydroxy-2,5-dimethyl-4-hexen-3-one, resulting in deuterium exchange at the C-5 methyl groups of 1. The lower-field gem-dimethyl signal of 1 in this medium is therefore assigned to these methyl groups. A similar relationship between the methyl proton signals of 1 in organic solvents has been demonstrated by (i) synthesis of 1-d8 (8), (ii) comparison of the 1H nmr spectra of 1 and its 2,2- and 5,5-dimethyl analogs, and (iii) observation of long range coupling in the spectrum of 1. Assignment of 13C chemical shifts for 1 has been made based on protoncoupled spectra, showing that the signal of the C-5 methyl carbons appears at ca. 4 ppm towards lower field than that of the C-2 methyl carbons. Both the 1H and 13C chemical shift assignments for 1 were confirmed from 13C{1H} spectra using low power single frequency 1H decoupling, demonstrating the utility of this technique for the assignment of chemical shifts.

21,22-Disubstituted 18α,19βH-Ursane Derivatives with Oxabicyclooctane System in Ring E

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca
Keyword(s):  
Spectral Data ◽  
Spin Systems ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
Proton Proton ◽  
H Nmr ◽  
Proton Coupling ◽  
C Nmr

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.

scholarly journals Beiträge zur Chemie des Phosphors, 204. Zur Existenz eines Triphosphacyclobutenid-Ions P3CH2Ɵ / Contributions to the Chemistry of Phosphorus, 204. On the Existence of a Triphosphacyclobutenide Ion P3CH2e

1990 ◽  
Vol 45 (8) ◽  
pp. 1139-1142 ◽  
Author(s):  
Marianne Baudler ◽  
Josef Hahn
Keyword(s):  
White Phosphorus ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Low Field

The structure of the reaction product of white phosphorus and sodium in diglyme which exhibits a low field AB2 system in the 31P{1H} NMR spectrum [4] has been reexamined. According to the results of a complete analysis of its proton coupled 31P NMR spectrum (ABB′XX′ system), the compound is the hitherto unknown 1,2,3-triphosphacyclopentadienide ion P3(CH)2⊖ (4), and not the triphosphacyclobutenide ion P3CH2⊖(3) previously assumed [4]. The parameters of the Ρ,Η-coupled 31P NMR spectrum of the tetraphosphacyclopentadienide ion P4CH⊖ (2) have also been calculated.

Beiträge zur Chemie des Phosphors, 234 [1,2] Lithium-tetrahydrogencyclopentaphosphid: Synthese, Struktur und Reaktionen / Contributions to the Chemistry of Phosphorus, 234 [1,2] Lithium Tetrahydrogen Cyclopentaphosphide: Synthesis, Structure and Reactions

1995 ◽  
Vol 50 (5) ◽  
pp. 786-790 ◽  
Author(s):  
Marianne Baudler ◽  
Rudolf Heumüller ◽  
Wolfgang Faber
Keyword(s):  
Low Temperature ◽  
Complete Analysis ◽  
Lemon Yellow ◽  
Compound I ◽  
Polar Solvents ◽  
Open Chain ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Nmr Parameters ◽  
Reaction Compound

Abstract Lithium tetrahydrogen cyclopentaphosphide. LiH4P5 (I). has been obtained by metalation of P2H4 at -78 °C with either n-BuLi or LiPH2 in polar solvents. Upon suitable performance of the reaction, compound I can be isolated at low temperature as a lemon-yellow solvent adduct. The structure as the monolithium salt of (PH)5 was confirmed by a complete analysis of the 31P{1H}-NMR spectrum. On warming above -35 °C, disproportionation occurs yield­ing Li2HP7. P2H4. and PH3. The reaction with n-BuLi produces the open-chain phosphides LiH4P3. LiH3P2, and LiPH2. The NMR parameters of LiH3P2 and LiH4P3 are reported. Reac­tion of 1 with P2H4 gives rise to the bicyclic and polycyclic phosphides LiH4P7, LiH5P8 and Li2H2P14, respectively.

Conformation of ring A in triterpenoid and 4,4-dimethylsteroid 3-ketones. Chemical shifts of methyl protons and lanthanide and benzene induced shifts

1990 ◽  
Vol 55 (3) ◽  
pp. 766-781 ◽  
Author(s):  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jarmil Světlý
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Methyl Groups ◽  
Pentacyclic Triterpene ◽  
H Nmr ◽  
Lanthanide Induced Shifts ◽  
Physical Data

Chemical shifts of signals due to methyl groups in position 10β (in CDCl3) and 4α and 4β (in C6D6) in 1H NMR spectra of pentacyclic triterpene 3-oxo derivatives (V, VIII, IX, and XII) are suitable for estimation of chair-boat equilibrium in the ring A. Benzene and lanthanide induced shifts of 4α and 4β-methyl protons were also used for this purpose. The results obtained with 2α-methyl-3-ketones (III, X) and 2β-methyl-3-ketones (IV, XI) as the respective chair and boat models agree well with those derived from other physical data (about 40% boat). The same methods were applied to 4,4-dimethylsteroid 3-ketones XV-XVII.

29Si, 13C and 31P NMR spectra of silicon-substituted ω-diphenylphosphinoalkyl silanes, (CH3)3-n(OC2H5)nSi(CH2)mP(C6H5)2

1982 ◽  
Vol 47 (3) ◽  
pp. 793-801 ◽  
Author(s):  
Jan Schraml ◽  
Martin Čapka ◽  
Harald Jancke
Keyword(s):  
Nmr Spectra ◽  
31P Nmr ◽  
Chemical Shifts ◽  
Additivity Rule ◽  
Ethoxy Group ◽  
Spectral Parameters ◽  
Nmr Spectrum ◽  
Nmr Parameters ◽  
13C And 31P Nmr ◽  
C Nmr

29Si, 13C, and 31P NMR spectra of a series of compounds of the structure (CH3)3-n(C2H5O)n.Si(CH2)mP(C6H5)2 (m = 1-6, n = )-3) are reported and assigned. Using monodeutero derivative of the compound with m = 3 and n = 0 an earlier assignment of 13C NMR spectrum is confirmed, but the assignment in the compounds with m = 4 is reversed. Introduction of ethoxy groups leads to violation of additivity rule for the 13C chemical shifts in the derivatives with m = 1. In all derivatives presence of one ethoxy group in the molecule has a profound effect on 31P chemical shift which is not changed by any further increase in the number of ethoxy groups in the molecule. The changes in 29Si chemical shifts follow the pattern known from other series of compounds. The observed trends in NMR parameters with changing n and m values can be explained by an interaction between phosphorus and oxygen atoms. Possible connections between the spectral parameters and catalysis employing the studied compounds are discussed.

Addition of the nitroxyl radical TEMPO to 1-naphthylketene: formation of an unusual adduct

1999 ◽  
Vol 77 (5-6) ◽  
pp. 806-809 ◽  
Author(s):  
Jennifer Carter ◽  
Michael H Fenwick ◽  
Wen-wei Huang ◽  
Vladimir V Popik ◽  
Thomas T Tidwell
Keyword(s):  
Nitroxyl Radical ◽  
Chemical Shifts ◽  
Wolff Rearrangement ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Naphthyl Ring ◽  
Nmr Signals ◽  
Very High

1-Naphthylketene (2), generated by thermal Wolff-rearrangement, is trapped in situ by 2,2,6,6-tetramethylpiridinyloxy radical (TEMPO, TO·) to form the adduct 1-naphthCH(OT)CO2T (4), whose structure is confirmed by an X-ray determination. The 1H NMR spectrum of 4 displays three CH3 groups with very high field chemical shifts (δ 0.10-0.47), and this is attributed to the location of these groups in the shielding region above the π system of the naphthyl ring. At -40°C, doubling of most of the 1H NMR signals occurs, and this is attributed to a freezing out of two conformations differing by rotation around the naphthyl—CH bond.Key words: ketene, TEMPO, restricted rotation, 1H NMR, conformational analysis, free radicals.

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