5-Cl-C4N2H3




 







 


Nitrogen and Chlorine


Nuclear Quadrupole Coupling Constants


in 5-Chloropyrimidine


 











 




Nitrogen and chlorine nqcc's in 5-chloropyrimidine were calculated on the structure given by B3P86/6-31G(3d,3p) optimization.  The results are shown in Tables 1 and 2.  Structure parameters are given in Table 3, rotational constants in Table 4, atomic coordinates in Table 5.
 
 








 









 







Table 1.  Nitrogen nqcc's in 5-Chloropyrimidine (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) optimized molecular structure.
 










Calc.
Expt. 
 







14N(1,3) Xaa - 0.136


Xbb -
 3.216



Xcc 3.352


Xab ± 2.693


 








RSD 0.030 (1.3 %)
 








Xxx 1.426


Xyy 3.352


Xzz -
 4.779



ETA
0.403



Øz,a
59.88



Øa,bi
58.32



Øz,bi*
  1.56

   







 








* The z-axis makes an angle of 1.56o with the external bisector ( 'bi' ) of the C(6)N(1)C(2) angle, and tilts toward C(6).

 








 








 







Table 2.  Chlorine nqcc's in 5-Chloropyrimidine (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) optimized molecular structure.
 










Calc.
Expt. 
 







35Cl Xaa - 73.73


Xbb
39.55



Xcc 34.18


ETA * - 0.073


 


RSD 0.49 (1.1 %)
 







37Cl Xaa - 58.10


Xbb 31.17


Xcc
26.93








RSD
0.44 (1.1 %)

   






 
* ETA = (Xbb - Xcc)/Xaa = (Xxx - Xyy)/Xzz.
 
 
Table 3.  5-Chloro- and 5-Fluoro-pyrimidine, and Pyrimidine.  Structure parameters ropt (Å and degrees).
 
X = Cl X = F X = H
C(2)N(3) 1.3315 1.3317 1.3320
N(3)C(4) 1.3299 1.3310 1.3328
C(4)C(5) 1.3893 1.3842 1.3877
C(2)H(2) 1.0867 1.0864 1.0876
C(4)H(4) 1.0868 1.0872 1.0879
C(5)X(5) 1.7238 1.3353 1.0835
N(1)C(2)N(3) 127.03 127.12 127.38
C(2)N(3)C(4) 116.34 116.39 115.70
N(3)C(4)C(5) 121.35 120.66 122.40
C(4)C(5)C(6) 117.59 118.78 116.44
C(5)C(4)H(4) 120.86 120.87 121.16
 
Table 4.  Rotational Constants (MHz).  35Cl species.
 
Calc. ropt Expt. 
A 6091.1
B 1631.4
C 1286.8
 
Table 5. Atomic coordinates, ropt   35Cl species.  
(More figures are shown than are significant.)
 
  a (Å)   b (Å)
N(1,3) - 1.608416 ± 1.191747
C(2) - 2.202233 0.0
C(4,6) - 0.278516 ± 1.188303
C(5) 0.441323 0.0
H(2) - 3.288901 0.0
H(4,6) 0.230604 ± 2.148522
Cl(5) 2.165088 0.0

 








 







Pyrimidine 4-Chloropyrimidine
2-Chloropyrimidine 2-Fluoropyrimidine
5-Fluoropyrimidine 2-Cyanopyrimidine
Tetrachloropyrimidine 2-Bromopyrimidine

 







 

Table of Contents




Molecules/Nitrogen




Molecules/Chlorine




 








 













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Last Modified 24 Feb 2004