Analysis of complex NMR spectra for the organic chemist: III. Four spin systems of the ABC2, ABX2, ABK2, AA'BB', and AA'XX' types

1968 ◽  
Vol 45 (7) ◽  
pp. 480 ◽  
Author(s):  
Edgar W. Garbisch
Keyword(s):  
Nmr Spectra ◽  
Spin Systems ◽  
Organic Chemist

scholarly journals The NMR Spin Systems of Scutellaria 8β,13-Epoxy-neo-clerod-3-en-15,16-olides and Revision of 1H and 13C NMR Spectra Reported Data

2020 ◽  
Vol 15 (10) ◽  
pp. 1934578X2093378
Author(s):  
Josep Coll Toledano
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Spin Systems ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Nmr Data ◽  
Reported Data ◽  
New Compounds ◽  
C Nmr ◽  
Shielding Effects

The present review of NMR spectroscopic structural elucidation data of new compounds isolated from Scutellaria species is focused on the title compounds, displaying a peculiar 13-spiro feature. It contains a compilation of 1H and 13C NMR data of these diterpenoids grouped by similar substitution patterns. Comparing shielding effects pointed out not only the identity of some compounds (already reported) but also potential misassignments and convenient revisions to get unambiguous structural proposals.

scholarly journals Identification of glycine spin systems in 1 H NMR spectra of proteins using multiple quantum coherences

FEBS Letters ◽  
1985 ◽  
Vol 186 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Jonathan Boyd ◽  
Christopher M. Dobson ◽  
Christina Redfield
Keyword(s):  
Nmr Spectra ◽  
Spin Systems ◽  
Multiple Quantum ◽  
H Nmr

1,2-Bis(2,6-diisopropylphenyl)diphosphane: a structural, spectroscopic, and computational investigation

2016 ◽  
Vol 94 (4) ◽  
pp. 392-400 ◽  
Author(s):  
Leila Mokhtabad Amrei ◽  
Peter W. Dibble ◽  
René T. Boeré
Keyword(s):  
Raman Spectrum ◽  
Nmr Spectra ◽  
Computational Analysis ◽  
Spin Systems ◽  
Solution Nmr ◽  
Computational Investigation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Peaks ◽  
Resolution Single

The title compound Dipp(H)P–P(H)Dipp where Dipp = 2,6-diisopropylyphenyl has been prepared starting from DippPH2 via DippPHLi reacting 2:1 with BrCH2CH2Br. A high-resolution single-crystal X-ray diffraction study at 153 ± 2 K provides an accurate description of the structure in the solid state, only the fourth dihydro diorganophosphane to have been so characterized. The Raman spectrum of the solid shows an intense, broad peak for P–H stretching at 2314 cm−1 and two peaks at 460 and 450 cm−1 for P–P stretching, assignments confirmed by RHF/6-31G+(3d,2p) frequency calculations undertaken on the anti conformers. 31P, 31P{1H }, 1H{31P}, and 13C{1H } solution NMR spectra in CDCl3 are consistent with the presence of 58% meso and 42% rac diastereomers. Analysis of their AA′XX′ spin systems enabled calculation of 1JPP′ values of (–)189 and (–)205 Hz, respectively. A B3LYP/6-31G(d,p) computational analysis of the energetics of rotation about the P–P bond in both diastereomers shows that the anti and two gauche conformers are likely to be populated approximately equally in each. The resulting average ϕ angles (torsions of the phosphorus lone pairs) are 110° for meso and 103° for rac; the smaller ϕ angle fits with the larger 1JPP′ value for the rac isomer.

Two Dimensional Double-Quantum and COSY Spectra of Porcine Adenylate Kinase

1984 ◽  
Vol 39 (7-8) ◽  
pp. 738-741 ◽  
Author(s):  
Paul Rösch ◽  
Karl-Heinz Gross
Keyword(s):  
Simple Form ◽  
Adenylate Kinase ◽  
Nmr Spectra ◽  
Spin Systems ◽  
Double Quantum ◽  
Two Dimensional ◽  
Aromatic Residues ◽  
Aromatic Region ◽  
Cosy Nmr ◽  
Cosy Spectra

Abstract1H double-quantum and COSY NMR-spectra of the porcine protein adenylate kinase have been obtained in order to assign aromatic spin systems within this protein, which contains seven tyrosyl, five phenylalanyl, and two histidyl residues. Double-quantum spectroscopy in its simple form allowed the assignment of five connectivities in the aromatic region and therefore proved inferior to COSY, which allowed the assignment of connectivities within nine aromatic residues.

Assignments of the1H and13C NMR spectra of pseudo-symmetric heterocyles using the HMQC-TOCSY experiment to differentiate overlapping spin systems

1992 ◽  
Vol 29 (7) ◽  
pp. 1805-1815 ◽  
Author(s):  
Lyle W. Castle ◽  
Milton D. Johnston ◽  
Charalampos L. Camoutsis ◽  
Raymond N. Castle
Keyword(s):  
Nmr Spectra ◽  
Spin Systems
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