3,4-Cl2-C5H3N



 

 








Nitrogen and Chlorine


Nuclear Quadrupole Coupling Constants


in 3,4-Dichloropyridine


 







 
 
Calculation was made of the nitrogen and chlorine nqcc tensors in 3,4-dichloropyridine on a molecular structure given 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 3,4-Dichloropyridine, normal species (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
 




Calc.
Expt.
   






14N Xaa - 3.323
Xbb 0.004
Xcc 3.319
|Xab| 2.712
 
RSD 0.030 (1.3 %)
 
  Xxx 1.522
Xyy 3.319
Xzz - 4.841
ETA 0.371
Øz,a 29.24
Øa,bi 28.24
Øz,bi *   1.00
 
 
* The z-axis makes an angle of 1.00o with the external bisector ( 'bi' ) of the C(6)N(1)C(2) angle, and tilts toward C(2).
 
 
   







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










Calc.
Expt.
   






35Cl(3) Xaa - 35.59
Xbb   2.37
Xcc 33.22
|Xab| 55.02
 
RSD 0.49 (1.1 %)
   
  Xxx 41.60
Xyy 33.22
Xzz - 74.81
ETA - 0.112
Øz,a 35.48
Øa,CCl 34.59
Øz,CCl   0.89
 
 
 
   







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










Calc.
Expt.
   






35Cl(4) Xaa - 44.35
Xbb 12.93
Xcc 31.41
|Xab| 50.89
 
RSD 0.49 (1.1 %)
   
  Xxx 42.69
Xyy 31.41
Xzz - 74.10
ETA - 0.152
Øz,a 30.31
Øa,CCl 29.23
Øz,CCl   1.08
 
 
 
 
Table 4.  3,4-Dichloropyridine.  Molecular structure parameters, ropt (Å and degrees).
 
N(1)C(2) 1.3276
C(2)C(3) 1.3945
C(3)C(4) 1.3946
C(4)C(5) 1.3897
C(5)C(6) 1.3872
C(6)N(1) 1.3330
C(2)H(2) 1.0865
C(3)Cl(3) 1.7187
C(4)Cl(4) 1.7169
C(5)H(5) 1.0829
C(6)H(6) 1.0867
C(6)N(1)C(2) 117.38
N(1)C(2)C(3) 123.69
C(2)C(3)C(4) 118.30
C(3)C(4)C(5) 118.30
C(4)C(5)C(6) 118.57
C(5)C(6)N(1) 123.76
N(1)C(2)H(2) 117.36
C(2)C(3)Cl(3) 119.55
C(3)C(4)Cl(4) 121.67
C(4)C(5)H(5) 120.16
C(5)C(6)H(6) 119.88


 
 
Table 5.  3,4-Dichloropyridine.  Atomic coordinates, ropt.  Normal species.
 
 a (Å)  b (Å)
N(1) 2.4585 0.6138
C(2) 1.3139 1.2866
C(3) 0.0591 0.6783
C(4) - 0.0003 - 0.7150
C(5) 1.1942 - 1.4253
C(6) 2.3871 - 0.7173
H(2) 1.3725 2.3716
Cl(3) - 1.3558 1.6541
Cl(4) - 1.4985 - 1.5535
H(5) 1.1832 - 2.5082
H(6) 3.3336 - 1.2513
 
 

Table 6.  3,4-Dichloropyridine.  Rotational Constants (MHz).   Normal species.
 
Calc ropt        Expt.
A  1936.3
B  1451.4
C    829.6


 
 

Pyridine 2-Chloropyridine 3-Chloropyridine

1,2-Dichlorobenzene 2,3-Dichloropyridine 2,4-Dichloropyridine
2,5-Dichloropyridine 2,6-Dichloropyridine 3,5-Dichloropyridine
 
 

Table of Contents





Molecules/Nitrogen




Molecules/Chlorine



 

 













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Last Modified 15 Nov 2003