4-Methylisothiazole




 
 
 
 


Nitrogen


Nuclear Quadrupole Coupling Constants


in 4-Methylisothiazole


 







 

 

 




Nitrogen nqcc's in 4-methylisothiazole were calculated on a structure given by mPW1PW91/aug-cc-pVTZ optimization (assuming Cs symmetry).  These are compared in Table 1 with the experimental nqcc's of Nicolaisen et al. [1].  Structure parameters are given here in Z-matrix (G03 input) format.  Rotational constants are given below in Table 2.
 
In Table 1, 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 4-Methylisothiazole (MHz).  Calculation was made on the mPW1PW91/aug-cc-pVTZ optimized structure, ropt.
   









Calc.
Expt. [1]
   





14N Xaa - 1.575 - 1.4822(14)
Xbb 0.205 0.0234 *
Xcc 1.370 1.4588 *
|Xab| 3.281 3.16(12)
 
RMS 0.128 (13.0 %)  
RSD 0.030 (1.3 %)
 


 







* Derived here from experimental Xaa and Xbb - Xcc = -1.4353(25) MHz.
 
 
Table 2.  4-Methylisothiazole.  Rotational Constants (MHz).
 
   ropt   Expt. [1]
A 7435.73 7370.642(31)
B 2535.16 2515.8461(30)
C 1912.85 1897.2863(33)
 
 

[1] H.-W.Nicolaisen, J.-U.Grabow, N.Heineking, and W.Stahl, Z.Naturforsch. 46a,635(1991).

 








 








Oxazole Isoxazole Thiazole Isothiazole
 

 








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Last Modified 19 Nov 2008