Details
| Original language | English |
|---|---|
| Pages (from-to) | 8684-8692 |
| Number of pages | 9 |
| Journal | Journal of Physical Chemistry A |
| Volume | 116 |
| Issue number | 34 |
| Publication status | Published - 30 Aug 2012 |
Abstract
N-Methylpiperidone (MPIP) and tropinone, which contain a structural motif found in numerous alkaloids, are too large to determine an accurate equilibrium structure either by ab initio methods or by experiment. However, the ground state rotational constants of the parent species and of all isotopologues with a substituted heavy atom ( 13C, 15N, 18O) are known from microwave spectroscopy. These constants have been corrected for the rovibrational contribution calculated from an ab initio cubic force field. These semiexperimental equilibrium rotational constants have been supplemented by carefully chosen structural parameters from medium level ab initio calculations. The two sets of data have been used in a weighted least-squares fit to determine reliable equilibrium structures for both molecules. This work shows that it is possible to determine reliable equilibrium structures for large molecules (34 degrees of freedom in the case of tropinone) at a detailed level of accuracy, and the method could be applied without too much difficulty to still larger molecules.
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
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In: Journal of Physical Chemistry A, Vol. 116, No. 34, 30.08.2012, p. 8684-8692.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Semiexperimental equilibrium structures for the equatorial conformers of N-methylpiperidone and tropinone by the mixed estimation method
AU - Demaison, Jean
AU - Craig, Norman C.
AU - Cocinero, Emilio J.
AU - Grabow, Jens Uwe
AU - Lesarri, Alberto
AU - Rudolph, Heinz Dieter
PY - 2012/8/30
Y1 - 2012/8/30
N2 - N-Methylpiperidone (MPIP) and tropinone, which contain a structural motif found in numerous alkaloids, are too large to determine an accurate equilibrium structure either by ab initio methods or by experiment. However, the ground state rotational constants of the parent species and of all isotopologues with a substituted heavy atom ( 13C, 15N, 18O) are known from microwave spectroscopy. These constants have been corrected for the rovibrational contribution calculated from an ab initio cubic force field. These semiexperimental equilibrium rotational constants have been supplemented by carefully chosen structural parameters from medium level ab initio calculations. The two sets of data have been used in a weighted least-squares fit to determine reliable equilibrium structures for both molecules. This work shows that it is possible to determine reliable equilibrium structures for large molecules (34 degrees of freedom in the case of tropinone) at a detailed level of accuracy, and the method could be applied without too much difficulty to still larger molecules.
AB - N-Methylpiperidone (MPIP) and tropinone, which contain a structural motif found in numerous alkaloids, are too large to determine an accurate equilibrium structure either by ab initio methods or by experiment. However, the ground state rotational constants of the parent species and of all isotopologues with a substituted heavy atom ( 13C, 15N, 18O) are known from microwave spectroscopy. These constants have been corrected for the rovibrational contribution calculated from an ab initio cubic force field. These semiexperimental equilibrium rotational constants have been supplemented by carefully chosen structural parameters from medium level ab initio calculations. The two sets of data have been used in a weighted least-squares fit to determine reliable equilibrium structures for both molecules. This work shows that it is possible to determine reliable equilibrium structures for large molecules (34 degrees of freedom in the case of tropinone) at a detailed level of accuracy, and the method could be applied without too much difficulty to still larger molecules.
UR - http://www.scopus.com/inward/record.url?scp=84865682928&partnerID=8YFLogxK
U2 - 10.1021/jp304178n
DO - 10.1021/jp304178n
M3 - Article
AN - SCOPUS:84865682928
VL - 116
SP - 8684
EP - 8692
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 34
ER -