ISSN:
1573-1111
Keywords:
π-π interaction
;
tripod hydrogen bonding
;
NOESY
;
relaxation time
;
chemical shift
;
molecular mechanics calculation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Significant π-π interaction is found in the complexes of (S, S)-dimethylpyridino-18-crown-6 with (R)- and (S)-[α-(1-naphthyl)ethyl]ammonium perchlorate. This finding is supported by the1H NOESY NMR spectral technique, greater chemical shift changes of aromatic protons in both host and guest molecules upon complexation, and by molecular mechanics calculations. Because of the flexibility of the ligand, the tripod hydrogen bonding causes13C relaxation times of all periphery carbons to decrease without significant selectivity. Rotational energy barrier calculations of the methyl groups of the complexed ligand also show that the (S, S)-host-(R)-guest is the more stable complex.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00709146
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