Other
Scientific paper
Jun 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010mss..confewh06g&link_type=abstract
"International Symposium On Molecular Spectroscopy, 65th Meeting, Held 21-25 June, 2010 at Ohio State University. http://molspec
Other
Microwave (Rotational)
Scientific paper
Nicotinoid alkaloids consist of two ring systems connected via a C-C σ-bond: Joining pyridine either with a (substituted) pyrrolidine or piperidine ring system, pyrrolidinic or piperidinic nicotinoids are formed. Nicotine itself, consisting of pyridine and N-methylpyrrolidine, is the prototype pyrrolidinic nicotinoid. Its coupled heteoaromatic and heteroaliphatic ring systems exhibit three sites that allow for conformational flexibility: (I) puckering of the pyrrolidine ring (Eq./Ax. positions of the pyridine), (II) inversion of the N-methyl group (Eq./Ax. positions of the hydrogen), and (III) relative orientation of the two rings (Syn-Anti). Two conformations of nicotine have been observed using the In-phase/quadrature-phase-Modulation Passage-Acquired-Coherence Technique (IMPACT) Fourier Transform Microwave (FTMW) spectrometer in Valladolid. The preferred conformations are characterized by an equatorial (Eq.) pyridine moiety and equatorial (Eq.) N-CH_3 stereochemistry. The planes of two rings are almost perpendicular with respect to each other while exhibiting two low energy conformations, Syn and Anti, that differ by a 180° rotation about the C-C σ-bond. The Eq.-Eq. conformational preference is likely due to a weak hydrogen bond interaction between the nitrogen lone pair at the N-methylpyrroline and the closest hydrogen in pyridine. Supporting quantum-chemical calculations are also provided.
Lavrich, R. J.; Suenram, R. D.; Plusquellic, D. F.; Davis, S. 58th International Symposium on Molecular Spectroscopy, Columbus, OH 2003, RH13.
Alonso Jose L.
Blanco Susana
Cabezas C.
Grabow Jens-Uwe
Lopez José C.
No associations
LandOfFree
Microwave Spectroscopy of Alkaloids: the Conformational Shapes of Nicotine does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Microwave Spectroscopy of Alkaloids: the Conformational Shapes of Nicotine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microwave Spectroscopy of Alkaloids: the Conformational Shapes of Nicotine will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1594402