Isoxazole




 
 


Nitrogen


Nuclear Quadrupole Coupling Constants


in Isoxazole


 







 

 


 




Nitrogen nqcc's in isoxazole and isoxazole-4D were calculated on the substitution structure of Stiefvater [1].  These are compared, for isoxazole, in Table 1 with the experimental nqcc's of Spoerel et al. [2]; and for isoxazole-4D in Table 2 with the experimental nqcc's of Sheridan et al. [3,4].  Structure parameters are given in Table 3.
 
In Tables 1 and 2, RMS is the root mean square difference between calculated and experimental 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.
 

 








   







Table 1.  Nitrogen nqcc's in Isoxazole (MHz).  Calculation was made on the rs structure of Stiefvater [1].
   










Calc.
Expt. [2]
   






14N Xaa 0.566 0.509(2)
Xbb - 0.433 - 0.512(2)
Xcc - 0.133 0.0022(10)
|Xab| 5.349 5.40(10)
 
RMS 0.096 (28 %)  
RSD 0.030 (1.3 %)
 


 







 
   







Table 2.  Nitrogen nqcc's in Isoxazole-4D (MHz).  Calculation was made on the rs structure of Stiefvater [1].
   










Calc.
Expt. [3]
   






14N Xaa - 5.243 - 5.33(4)
Xbb 5.376 5.31(7)
Xcc - 0.133 0.02(11)
|Xab| 0.821
 
RMS 0.11 (3.0 %)  
RSD 0.030 (1.3 %)
 
 
 
 
 
Table 3. Molecular structure parameters, rs [1] (Å and degrees).
 
O(1)N(2) 1.3995
N(2)C(3) 1.3132

C(3)C(4) 1.4260
C(4)C(5) 1.3598
C(5)O(1) 1.3457
C(3)H(3) 1.0751
C(4)H(4) 1.0720
C(5)H(5) 1.0728
C(5)O(1)N(2) 108.82
O(1)N(2)C(3) 105.36
N(2)C(3)C(4) 112.22
C(3)C(4)C(5) 103.06
C(4)C(5)O(1) 110.54
C(4)C(3)H(3) 129.09
C(3)C(4)H(4) 128.46
C(4)C(5)H(5) 133.40


 
 

[1] O.L.Stiefvater, J.Chem.Phys. 63,2560(1975).
[2] U.Spoerel, H.Dreizler, W.Stahl, E.Kraka, and D.Cremer, J.Phys.Chem. 100,14298(1996).
[3] S.E.Lowe and J.Sheridan, Chem.Phys.Lett. 58,79(1978).
[4] O.L.Stiefvater, P.Nösberger, and J.Sheridan, Chem.Phys. 9,435(1975).

 








 








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Last Modified 3 July 2008