2-Hydroxypyridine


















 




 








Nitrogen and Deuterium


Nuclear Quadrupole Coupling Constants

in 2-Hydroxypyridine


 








 








 








Nitrogen and Deuterium (O-D) nqcc's in 2-hydroxypyridine were determined by Tanjaroon et al. [1].

 








Calculation of the nqcc's was made here on molecular structures derived by B3P86/6-31G(d,p) and B3P86/6-31G(3d,3p) optimizations.  Calculated and experimental nqcc's are compared in Tables 1 - 3.  Structure parameters are given in Table 4, rotational constants in Table 5.

 








In Tables 1 - 3, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

 








RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of nitrogen nqcc's; and of the B3LYP/6-31G(df,3p) model for calculation of the deuterium nqcc's.

 








 








   








Table 1.   14N nqcc's in 2-Hydroxypyridine (MHz).  Calculation was made on (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3p) optimized structures.
   










Calc. (1)

Calc. (2)
Expt. [1]
   








Xaa - 0.086 - 0.094 - 0.076(11)

Xbb - 2.161 - 2.174 - 2.283(6)

Xcc
2.246
2.268
2.359(6)

|Xab|
2.733
2.729



 







RMS
0.096 (6.1 %)
0.082 (5.2 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
1.800
1.787



Xyy
2.246
2.268



Xzz - 4.047 - 4.055



ETA
0.110
0.119



z,a
55.39
55.43



a,bi a 
56.54
56.56



z,bi 
  1.15
  1.12



 








 








a "bi" is the bisector of the CNC angle.

 








  








   








Table 2.   14N nqcc's in 2-Deuteriohydroxypyridine (MHz).  Calculation was made on (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3p) optimized structures.
   










Calc. (1)

Calc. (2)
Expt. [1]
   








Xaa - 0.200 - 0.208 - 0.1465(4)

Xbb - 2.046 - 2.060 - 2.2045(4)

Xcc
2.246
2.268
2.3510(4)

|Xab|
2.774
2.770



 







RMS
0.114 (7.2 %)
0.102 (6.5 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 








 








 








   








Table 3.   2H nqcc's in 2-Deuteriohydroxypyridine (kHz).  Calculation was made on (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3p) optimized structures.
   










Calc. (1)

Calc. (2)
Expt. [1]
   








Xaa
- 70.3
- 70.5
- 25.0(9)

Xbb
221.4
223.8
169.9(4)

Xcc
151.1 - 153.3 - 144.9(4)

|Xab|
126.1
129.4



 







RMS
39.8 (35 %)
40.1 (36 %)



RSD
1.1 (0.86 %)
1.1 (0.86 %)



 







Xxx - 117.3 - 119.3



Xyy - 151.1 - 153.3



Xzz
268.4
272.6



ETA
0.126
0.124



z,a
69.58
69.33



a,OH
71.44
71.11



z,OH
  1.86
  1.78



 








 








 



Table 4.   2-Hydroxypyridine.  Selected structure parameters ( and degrees).  Complete structures are given here in Z-matrix format.
 



Click on image ropt (1)  B3P86/6-31G(d,p)
to enlarge. ropt (2)  B3P86/6-31G(3d,3p)
 





ropt (1) ropt (2)

 
 

C(1)N 1.3380 1.3360
NC(5) 1.3272 1.3249
C(1)NC(5) 117.45 117.40
CO 1.3465 1.3464
OH 0.9691 0.9670
NC(5)C(4) 124.11 124.12
COH 105.49 105.79
 



The "tautomeric" hydrogen atom is rs = 2.653(2) from the center of mass of the molecule [1].  On the B3P86/6-31G(d,p) structure, it is 2.6450 ; and on the B3P86/6-31G(3d,3p) structure, 2.6460 .



 








 



Table 5.   2-Hydroxypyridine.  Rotational Constants (MHz).  Normal Species.
 




ropt (1) = B3P86/6-31G(d,p) optimization.

ropt (2) = B3P86/6-31G(3d,3p) optimization.






  Calc. ropt (1) Calc. ropt (2)    Expt. [1]






A     5848.7     5868.2

B     2780.0     2787.3

C     1884.3     1889.7


 








 








[1] C.Tanjaroon, R.Subramanian, C.Karunatilaka, and S.G.Kukolich, J.Phys.Chem. A 108,9531(2004).

 








L.D.Hatherley, R.D.Brown, P.D.Godfrey, A.P.Pierlot, W.Caminati, D.Damiani, S.Melendri, and L.B.Favero, J.Phys.Chem. 47,46(1993).


 









 








3-Hydroxypyridine 4-Hydroxypyridine



Pyridine 2-Pyridone Quinoline

Formic Acid 2-Methylpyridine
Isoquinoline

 








 








Table of Contents




Molecules/Nitrogen




 








 













2OHPyridine.html






Last Modified 1 Oct 2007