|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Anabasine
3-(2-piperidyl)pyridine
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Nitrogen
|
|
|
Nuclear
Quadrupole Coupling Constants |
|
|
|
in
Anabasine |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rotational spectra of two conformers
of anabasine, syn
and anti, have been
investigated by
Lesarri et al. [1]. Diagonal components of the 14N
inertial axes nqcc tensors were determined.
|
|
|
|
|
|
|
|
|
|
|
|
|
Calculation of the N nqcc tensors was
made here on molecular structures optimized at the
B3P86/6-31G(3d,3p) level of theory. These structures are
shown below. Calculation of
the molecular PE at the B3PW91/6-311+G(df,pd) level of theory on these
optimized
structures gives Esyn < Eanti by about 2.5 kJ/mol.
Calculated and
experimental nqcc's are compared in Tables 1 and 2. Rotational
constants and dipole moments are given in Table 3. |
|
|
|
|
|
|
|
|
|
|
|
|
|
syn |
|
|
anti |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
In Tables 1 and 2, subscripts a,b,c
refer to
the principal axes of the inertia tensor, subscripts x,y,z to the
principal axes of the nqcc tensor. ETA = (Xxx - Xyy)/Xzz. |
|
|
RMS is the root mean square
difference between calculated and experimental diagonal nqcc's (percent
of the average of the magnitudes of experimental nqcc's). RSD is
the residual standard deviation of the model for calculation of the
nqcc's, which may be taken as an estimate of uncertainty in the
calculated nqcc's (not taking into account inaccuracies in the
structure parameters). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
Table 1. 14N nqcc's in syn Anabasine
(MHz). N(6) is piperidinic nitrogen, N(20) is pyridinic.
Calculation was made
on the B3P86/6-31G(3d,3p) opt structure. |
|
| |
|
|
|
|
|
|
|
|
|
|
|
Calc |
|
Expt [1] |
|
| |
|
|
|
|
|
|
|
|
14N(6) |
Xaa |
|
2.489 |
|
2.46198(43) |
|
|
|
Xbb |
|
0.467 |
|
0.403(24) |
|
|
|
Xcc |
- |
2.957 |
- |
2.865(24) |
|
|
|
Xab |
|
0.560 |
|
|
|
|
|
Xac |
- |
0.425 |
|
|
|
|
|
Xbc |
|
3.298 |
|
|
|
|
|
|
|
|
|
|
|
|
|
RMS |
|
0.067 (3.5 %) |
|
|
|
|
|
RSD |
|
0.030 (1.3 %) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Xxx |
|
2.249 |
|
|
|
|
|
Xyy |
|
2.769 |
|
|
|
|
|
Xzz |
- |
5.018 |
|
|
|
|
|
ETA |
|
0.104 |
|
|
|
|
|
|
|
|
|
|
|
|
|
---------------------------------------------------------------------------- |
|
|
|
|
|
|
|
|
|
|
14N(20) |
Xaa |
- |
0.982 |
- |
0.9731(48) |
|
|
|
Xbb |
- |
0.462 |
- |
0.331(26) |
|
|
|
Xcc |
|
1.444 |
|
1.305(26) |
|
|
|
Xab |
- |
2.593 |
|
|
|
|
|
Xac |
|
1.662 |
|
|
|
|
|
Xbc |
|
2.796 |
|
|
|
|
|
|
|
|
|
|
|
|
|
RMS |
|
0.110 (12.7 %) |
|
|
|
|
|
RSD |
|
0.030 (1.3 %) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Xxx |
|
1.435 |
|
|
|
|
|
Xyy |
|
3.456 |
|
|
|
|
|
Xzz |
- |
4.891 |
|
|
|
|
|
ETA |
|
0.413 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
Table 2. 14N nqcc's in anti Anabasine
(MHz). N(6) is piperidinic nitrogen, N(20) is pyridinic.
Calculation was made
on the B3P86/6-31G(3d,3p) opt structure. |
|
| |
|
|
|
|
|
|
|
|
|
|
|
Calc |
|
Expt [1] |
|
| |
|
|
|
|
|
|
|
|
14N(6) |
Xaa |
|
2.475 |
|
2.4920(93) |
|
|
|
Xbb |
|
0.485 |
|
0.254(31) |
|
|
|
Xcc |
- |
2.960 |
- |
2.746(31) |
|
|
|
Xab |
- |
0.630 |
|
|
|
|
|
Xac |
- |
0.529 |
|
|
|
|
|
Xbc |
- |
3.312 |
|
|
|
|
|
|
|
|
|
|
|
|
|
RMS |
|
0.182 (9.9 %) |
|
|
|
|
|
RSD |
|
0.030 (1.3 %) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Xxx |
|
2.261 |
|
|
|
|
|
Xyy |
|
2.789 |
|
|
|
|
|
Xzz |
- |
5.051 |
|
|
|
|
|
ETA |
|
0.104 |
|
|
|
|
|
|
|
|
|
|
|
|
|
-------------------------------------------------------------------------- |
|
|
|
|
|
|
|
|
|
|
14N(20) |
Xaa |
|
0.746 |
|
0.764(10) |
|
|
|
Xbb |
- |
1.531 |
- |
1.552(33) |
|
|
|
Xcc |
|
0.785 |
|
0.788(33) |
|
|
|
Xab |
- |
1.510 |
|
|
|
|
|
Xac |
- |
1.271 |
|
|
|
|
|
Xbc |
- |
3.693 |
|
|
|
|
|
|
|
|
|
|
|
|
|
RMS |
|
0.016 (1.5 %) |
|
|
|
|
|
RSD |
|
0.030 (1.3 %) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Xxx |
|
1.422 |
|
|
|
|
|
Xyy |
|
3.505 |
|
|
|
|
|
Xzz |
- |
4.927 |
|
|
|
|
|
ETA |
|
0.422 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The B3P86/6-31G(3d,3p) optimized
structures of these conformers are given in Z-matrix format here: syn
and anti.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Table 3. Anabasine.
Rotational constants (MHz) and dipole moments (D). Calc is
on the
B3P86/6-31G(3d,3p) opt structure. |
|
|
|
|
|
________________syn__________________ |
|
|
|
|
|
|
Calc |
Expt. [1] |
|
|
|
|
|
A |
2541.4 |
2523.91921(18) |
|
B |
508.8 |
505.16717(16) |
|
C |
486.1 |
485.22787(12) |
|
|
|
|
|
|µa| |
2.20 |
|
|
|µb| |
1.12 |
|
|
|µc| |
0.33 |
|
|
|
|
|
|
________________anti_________________ |
|
|
|
|
|
A |
2524.2 |
2505.84766(32) |
|
B |
512.0 |
509.00907(15) |
|
C |
487.7 |
486.45464(14) |
|
|
|
|
|
|µa| |
1.55 |
|
|
|µb| |
2.01 |
|
|
|µc| |
1.92 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Pyridine
|
Piperidine |
Nicotine |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
[1] A.Lesarri, E.J.Cocinero,
L.Evangelisti, R.D.Suenram, W.Caminati, and J.-U.Grabow, Chem.Euro.J.
16,10214(2010). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Table of Contents |
|
|
|
|
|
Molecules/Nitrogen |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
anabasine.html |
|
|
|
|
|
|
Last
Modified 1 Aug 2010 |
|
|
|
|
|
|
|
|
|
|