2-CHO-C5H4N



 








Nitrogen

Nuclear Quadrupole Coupling Constants


in 2-Pyridine Carbaldehyde


 







 

 

 




The molecular structure of 2-pyridine carbaldehyde was optimized at the B3P86/6-31G(3d,3p) level of theory. Cs symmetry was assumed.  On this structure calculation was made of the nitrogen nqcc's.  These are given in Table 1. Structure parameters are given in Table 2, atomic coordinates in Table 3, rotational constants in Table 4.
 
In Table 1, 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.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's.
 

 







   






Table 1.  Nitrogen nqcc's in 2-Pyridine Carbaldehyde (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
 




Calc.
Expt.
   





14N Xaa 0.381
Xbb - 3.961
Xcc 3.580
|Xab| 2.245
 
RSD 0.030 (1.3 %)
 
  Xxx 1.333
Xyy 3.580
Xzz - 4.913
ETA 0.456
Øz,a 67.02
Øa,bi 67.99
Øz,bi *   0.97
 
 
* The z-axis makes an angle of 0.97o with the external bisector ( 'bi' ) of the C(6)N(1)C(2) angle, and tilts toward C(2).
 
 
 
Table 2.  2-Pyridine Carbaldehyde and Pyridine.  Molecular structure parameters, ropt (Å and degrees).
 
2-CHO-Pyridine Pyridine
N(1)C(2) 1.3380 1.3336
C(2)C(3) 1.3931 1.3904
C(3)C(4) 1.3860 1.3885
C(4)C(5) 1.3897 1.3885
C(5)C(6) 1.3928 1.3904
C(6)N(1) 1.3294 1.3336
C(3)H(3) 1.0841 1.0845
C(4)H(4) 1.0848 1.0851
C(5)H(5) 1.0843 1.0845
C(6)H(6) 1.0874 1.0880
C(6)N(1)C(2) 117.20 117.03
N(1)C(2)C(3) 123.91 123.80
C(2)C(3)C(4) 118.17 118.44
C(3)C(4)C(5) 118.52 118.50
C(4)C(5)C(6) 118.83 118.44
C(5)C(6)N(1) 123.37 123.80
C(2)C(3)H(3) 119.12 120.21
C(3)C(4)H(4) 120.82 120.75
C(6)C(5)H(5) 120.05 120.21
N(1)C(6)H(6) 116.24 115.94
 
C(2)C 1.4860
CO 1.2079
CH 1.1082
N(1)C(2)C 115.26
C(2)C=O 123.87
C(2)CH 113.69


 
 
Table 3.  2-Pyridine Carbaldehyde.  Atomic coordinates, ropt.
 
 a (Å)  b (Å)
N(1) - 0.3442 1.2723
C(2) 0.4534 0.1981
C(3) - 0.0115 - 1.1151
C(4) - 1.3816 - 1.3242
C(5) - 2.2218 - 0.2172
C(6) - 1.6558 1.0553
H(3) 0.7052 - 1.9285
H(4) - 1.7906 - 2.3290
H(5) - 3.3000 - 0.3319
H(6) - 2.2893 1.9391
C 1.9104 0.4901
O 2.7675 - 0.3610
H 2.1474 1.5726
 
 

Table 4.  2-Pyridine Carbaldehyde.  Rotational Constants (MHz).
 
Calc ropt   Expt. [1]
A 5398.7 5362.52(219)
B 1629.7 1620.07(3)
C 1251.8 1244.42(3)


 
 
[1] Y.Kawashima, M.Suzuki, and K.Kozima, Bull.Chem.Soc.Jpn 48,2009(1975).
 
 

Pyridine 3-Pyridine Carbaldehyde 4-Pyridine Carbaldehyde

2-Fluoropyridine 2-Chloropyridine 2-Bromopyridine
2-Methylpyridine 2-Cyanopyridine
 
 

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Molecules/Nitrogen



 

 













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Last Modified 12 Dec 2003