2-Cl-4-F-C5H3N



 

 








Nitrogen and Chlorine


Nuclear Quadrupole Coupling Constants

in 2-Chloro-4-Fluoropyridine


 







 
 
Calculation was made of the nitrogen and chlorine nqcc tensors in 2-chloro-4-fluoropyridine on a molecular structure giveen by B3P86/6-31G(3d,3p) optimization.  These are shown in Tables 1 - 3.  Structure parameters are given in Table 4, atomic coordinates in Table 5, and rotational constants in Table 6.
 
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.  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 model for calculation of the nqcc's.
 

 







   







Table 1. Nitrogen nqcc's in 2-35Cl-4-Fluoropyridine (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
 




Calc.
Expt.
   






14N Xaa - 1.940
Xbb - 0.772
Xcc 2.712
|Xab| 3.159
 
RSD 0.030 (1.3 %)
 
  Xxx 1.857
Xyy 2.712
Xzz - 4.568
ETA 0.187
Øz,a 39.76
Øa,bi 39.64
Øz,bi *   0.12
 
 
* The z-axis makes an angle of 0.12o with the external bisector ( 'bi' ) of the C(6)N(1)C(2) angle, and tilts toward C(2).
 
 
   







Table 2.  Chlorine nqcc's in 2-35Cl-4-Fluoropyridine (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
   










Calc.
Expt.
   






35Cl Xaa - 60.50
Xbb 30.14
Xcc 30.36
|Xab| 33.73
 
RSD 0.49 (1.1 %)
   
  Xxx 41.31
Xyy 30.36
Xzz - 71.67
ETA - 0.153
Øz,a 18.33
Øa,CCl 18.58
Øz,CCl   0.25
 
 
 
   







Table 3.  Nitrogen and Chlorine nqcc's in 2-37Cl-4-Fluoropyridine (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
   










Calc.
Expt.
   






14N Xaa - 1.890
Xbb - 0.821
Xcc 2.712
|Xab| 3.168
   
RSD 0.030 (1.3 %)
   
37Cl Xaa - 48.09
Xbb 24.17
Xcc 23.92
|Xab| 26.02
   
RSD 0.44 (1.1 %)
 
 
 
 
Table 4.  2-Chloro-4-Fluoropyridine.  Molecular structure parameters, ropt (Å and degrees).
 
N(1)C(2) 1.3180
C(2)C(3) 1.3919
C(3)C(4) 1.3817
C(4)C(5) 1.3856
C(5)C(6) 1.3870
C(6)N(1) 1.3352
C(2)Cl(2) 1.7350
C(3)H(3) 1.0818
C(4)F(4) 1.3332
C(5)H(5) 1.0822
C(6)H(6) 1.0865
C(6)N(1)C(2) 116.91
N(1)C(2)C(3) 125.22
C(2)C(3)C(4) 115.80
C(3)C(4)C(5) 121.40
C(4)C(5)C(6) 116.53
C(5)C(6)N(1) 124.14
N(1)C(2)Cl(2) 116.67
C(2)C(3)H(3) 122.52
C(3)C(4)F(4) 119.05
C(4)C(5)H(5) 121.15
C(5)C(6)H(6) 120.10


 
 
Table 5.  2-35Cl-4-Fluoropyridine.  Atomic coordinates, ropt.  Normal species.
 
 a (Å)  b (Å)
N(1)
0.5940 1.3769
C(2) 0.7795 0.0720
C(3) - 0.2332 - 0.8829
C(4) - 1.5242 - 0.3903
C(5) - 1.7770 0.9720
C(6) - 0.6698 1.8075
Cl(2) 2.4241 - 0.4808
H(3) - 0.0307 - 1.9455
F(4) - 2.5445 - 1.2485
H(5) - 2.7897 1.3535
H(6) - 0.8011 2.8861
 
 

Table 6.  2-35Cl-4-Fluoropyridine.  Rotational Constants (MHz).   Normal species.
 
Calc ropt        Expt.
A  3607.6
B  1200.4
C    900.7


 
 

Pyridine 2-Chloropyridine 2,4-Dichloropyridine

2-Chloro-3-Fluoropyridine 2-Chloro-5-Fluoropyridine 2-Chloro-6-Fluoropyridine
 
 

Table of Contents





Molecules/Nitrogen




Molecules/Chlorine



 

 













24CFP.html






Last Modified 15 Nov 2003