13C-NMR chemische Verschiebung phenylsubstituierter polycyclischer Kohlenwasserstoffe / 13C-NMR Chemical Shift of Phenylsubstituted Polycyclic Hydrocarbons

13C-NMR spectra of tetracene, rubrene, 1,3,5-tri-, penta-, and hexaphenylbenzene are reported. The discussion also includes the already known 13C-NMR data for diphenyl, 9,10-diphenyl-, 9,10-dibenzyl-, and 9,10-dimethyl-anthracene [1] as well as toluene. On the basis of CNDO/2 calculations different influences (diamagnetic and paramagnetic term, anisotropic contribution, ring current effect, geometry) on the chemical shift are analyzed for diphenyl and within the row benzene through tetracene

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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

Natural Product Communications ◽

10.1177/1934578x20933785 ◽

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.

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Effect of the π-Electron Ring Current on the 1H NMR Spectra of 1,1'-Binaphthol Derivatives

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19930077 ◽

1993 ◽

Vol 58 (1) ◽

pp. 77-81 ◽

Cited By ~ 3

Author(s):

Gustavo Marin-Puga ◽

Václav Horák ◽

Paris Svornos

Keyword(s):

High Resolution ◽

1H Nmr ◽

Nmr Spectra ◽

Close Agreement ◽

Ring Current ◽

Chemical Shifts ◽

Current Effect ◽

H Nmr ◽

Ring Current Effect ◽

Cosy Nmr

High resolution 1H NMR spectra of two 1,1'-binaphthols (I, II), two 1,1'-binaphthalenediols (III, IV) and four 1,1'- binaphthalenediols acetates (IIIa - IVa) were obtained and analyzed. The effect of the ring current was evaluated by comparing the chemical shifts of the compounds, assigned through H-H COSY NMR experiments, to those of the corresponding monomers. All experimental chemicals shifts are in close agreement with the theoretical values obtained via the Bovey model for the ring current effect of a benzene moiety.

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The 1H and 13C NMR Chemical Shift Assignments for Thirteen Bufadienolides Isolated from the Traditional Chinese Drug Ch'an Su

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20011841 ◽

2001 ◽

Vol 66 (12) ◽

pp. 1841-1848 ◽

Cited By ~ 12

Author(s):

Yoshiaki Kamano ◽

Toshihiko Nogawa ◽

Ayano Yamashita ◽

George R. Pettit

Keyword(s):

Chemical Shift ◽

13C Nmr ◽

Nmr Spectra ◽

2D Nmr ◽

Chinese Drug ◽

Chemical Shift Assignments ◽

1H And 13C Nmr ◽

Nmr Chemical Shift Assignments ◽

2D Nmr Spectra ◽

C Nmr

The 1H and 13C NMR spectra of thirteen natural bufadienolides, which were isolated from the Chinese drug Ch'an Su, were assigned using a combination of 2D NMR spectra that included 1H-1H COSY, NOESY, HMQC, and HMBC techniques.

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(Anti)aromaticity of dehydroannulenes of various ring size proved by the ring current effect in 1H NMR spectra

Tetrahedron ◽

10.1016/j.tet.2012.12.019 ◽

2013 ◽

Vol 69 (5) ◽

pp. 1481-1488 ◽

Cited By ~ 9

Author(s):

Erich Kleinpeter ◽

Andreas Koch

Keyword(s):

1H Nmr ◽

Nmr Spectra ◽

Ring Current ◽

1H Nmr Spectra ◽

Ring Size ◽

Current Effect ◽

Ring Current Effect

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Identification of substituted furyltetrazolyl acetates by means of 13C NMR spectrometry

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19841895 ◽

1984 ◽

Vol 49 (8) ◽

pp. 1895-1899 ◽

Cited By ~ 1

Author(s):

Jan Světlík ◽

Igor Goljer ◽

Ľubomír Janda

Keyword(s):

Chemical Shift ◽

13C Nmr ◽

Ring System ◽

Tetrazole Ring ◽

Nmr Data ◽

Nmr Spectrometry ◽

C Nmr

13C NMR data of a series of 5-[5-(substituted phenyl)-2-furyl]-1- and -2-tetrazolyl acetates are presented. Examination of diagnostic resonances emphasizing particularly those arising from the tetrazole ring system enabled both isomers to be easily distinguished. The chemical shift increment for 5-(2-furyl)-1- and -2-tetrazolyl acetate unit has been deduced.

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13C NMR spectra of 1-aryl-ferrocenylethylenes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19860670 ◽

1986 ◽

Vol 51 (3) ◽

pp. 670-676 ◽

Cited By ~ 5

Author(s):

Eva Solčániová ◽

Štefan Toma ◽

Tibor Liptaj

Keyword(s):

13C Nmr ◽

Nmr Spectra ◽

Substituent Effects ◽

13C Nmr Spectra ◽

Bridge Group ◽

C Nmr ◽

Electron Effects

13C NMR spectra of 18 ferrocene analogues of trans stilbenes (1-aryl-2-ferrocenylethylenes) were measured. It was found that bridge group weakens the transfer of the substituent electron effects into ferrocene nucleus, especially distinctly into 3',4'positions of cyclopentadienyl ring. The transfer of substituent effects into β-position of the bridge -CH=CH- is greater in derivatives studied by us than in stilbenes. Synthesis of 1-(4-dimethylaminophenyl)-2-ferrocenylethylene is described.

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17O and 13C NMR spectra of some geminal diacetates

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19880588 ◽

1988 ◽

Vol 53 (3) ◽

pp. 588-592 ◽

Cited By ~ 10

Author(s):

Antonín Lyčka ◽

Josef Jirman ◽

Jaroslav Holeček

Keyword(s):

13C Nmr ◽

Nmr Spectra ◽

Chemical Shifts ◽

The Other ◽

13C Nmr Spectra ◽

Other Hand ◽

Carboxylic Esters ◽

C Nmr ◽

Oxygen Atoms

The 17O and 13C NMR spectra of eight geminal diacetates RCH(O(CO)CH3)2 derived from simple aldehydes have been measured. In contrast to the dicarboxylates R1R2E(O(CO)R3)2, where E = Si, Ge, or Sn, whose 17O NMR spectra only contain a single signal, and, on the other hand, in accordance with organic carboxylic esters, the 17O NMR spectra of the compound group studied always exhibit two well-resolved signals with the chemical shifts δ(17O) in the regions of 183-219 ppm and 369-381 ppm for the oxygen atoms in the groups C-O and C=O, respectively.

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Proximity and conformation effects in 29Si and 13C NMR spectra of di-ortho substituted trimethylsiloxybenzenes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19902027 ◽

1990 ◽

Vol 55 (8) ◽

pp. 2027-2032 ◽

Cited By ~ 1

Author(s):

Jan Schraml ◽

Robert Brežný ◽

Jan Čermák

Keyword(s):

Benzene Ring ◽

13C Nmr ◽

Proximity Effect ◽

Nmr Spectra ◽

Methoxy Group ◽

Chemical Shifts ◽

Proximity Effects ◽

13C Nmr Spectra ◽

Methoxy Groups ◽

C Nmr

29Si and 13C NMR spectra of five 4-substituted 2,6-dimethoxytrimethylsiloxybenzenes were studied with the aim to elucidate the nature of the deshielding proximity effects observed in the spectra of ortho substituted trimethylsiloxybenzenes. The sensitivity of 29Si chemical shifts to para substitution is in the studied compounds essentially the same as in mono ortho methoxytrimethylsiloxybenzenes. The deshielding proximity effect of the ìsecondî methoxy group is somewhat smaller than that of the ìfirstî group. The present results indicate that the two methoxy groups assume coplanar conformations with the benzene ring and are turned away from the trimethylsiloxy group which is not in the benzene plane. It is argued that in mono ortho methoxytrimethylsiloxybenzenes the two substituent groups adopt the same conformations as in the compounds studied here.

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Structural Investigations of C-Nitrosobenzenes. Part 3.1 Solid-state and Solution 13C NMR Studies, and Crystal Structure of E-(4-CIC6H4NO)2

Journal of Chemical Research ◽

10.1177/174751989902300316 ◽

1999 ◽

Vol 23 (3) ◽

pp. 202-203

Author(s):

Daniel A. Fletcher ◽

Brian G. Gowenlock ◽

Keith G. Orrell ◽

David C. Apperley ◽

Michael B. Hursthouse ◽

...

Keyword(s):

Crystal Structure ◽

Solid State ◽

13C Nmr ◽

Nmr Studies ◽

Structural Investigations ◽

Nmr Data ◽

C Nmr

Solid-state and solution 13C NMR data for the monomers and dimers of 3- and 4-substituted nitrosobenzenes, and the crystal structure of E-(4-CIC6H4NO)2 are reported.

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