ChemInform Abstract: Benzocyclynes Adhere to Hueckel′s Rule by the Ring Current Criterion in Experiment (1H NMR) and Theory (NICS)

ChemInform ◽  
2010 ◽  
Vol 29 (48) ◽  
pp. no-no
Author(s):  
A. J. MATZGER ◽  
K. P. C. VOLLHARDT
1998 ◽  
Vol 9 (6) ◽  
pp. 955-965 ◽  
Author(s):  
Cirilo Garcı́a-Martı́nez ◽  
Yoichi Taguchi ◽  
Akihiro Oishi ◽  
Kikuko Hayamizu

1979 ◽  
Vol 20 (5) ◽  
pp. 437-440 ◽  
Author(s):  
Alexandru T. Balaban ◽  
Antonie Dinculescu ◽  
Hristos N. Koutrakis ◽  
Filip Chiraleu

1993 ◽  
Vol 58 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Gustavo Marin-Puga ◽  
Václav Horák ◽  
Paris Svornos

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.


1978 ◽  
Vol 33 (9) ◽  
pp. 1026-1032 ◽  
Author(s):  
Hans-Dieter Eßwein ◽  
Günter Häfelinger

The 1,4-Dimenthyl-9-antliracenyl group is useful as a ring current probe for a 9-phenyl substituent. The splitting between the 1- and 4-methyl group signals due to the diamagnetic ring current anisotropy of the 9-phenylring is 0.84 ppm (0.85 ppm in 9-mesityl- 1,4-dimethylanthracene and 0.86 ppm in 9-phenyl-l,4,6,7-tetramethylanthracene), much larger than in phenylmesitylene (0.32 ppm). In 9-phenyl-1,4-dimethyltriptycene the splitting is reduced to 0.55 ppm due to the change in geometry. By use of an assumed geometric model for all four compounds the magnitude of the splitting could be predicted with a maximum deviation of 0.09 ppm using the tables of Haigh and Mallion. As effective magnetic location for the methyl group the midpoint of the basis of the CH3 cone was chosen. In 9-phenyl-1,4,5,8-tetramethyltriptycene the 9-phenyl ring is not orientated perpendicular but parallel to the 1,8-methyl groups and as the analysis of the ABCX-spin-spin system of the unsubstituted phenyl ring shows tilted by about 24 ° away from the 1,8- methylgroups.


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