C6H3-(CN)3























 





 








Nitrogen


Nuclear Quadrupole Coupling Constants


in 1,2,3-Tricyanobenzene


 








 








 


 





Calculation of the nitrogen nqcc's in 1,2,3-tricyanobenzene was made here on a molecular structure (C2V)  given by B3P86/6-31G(3d,3p) optimization.  These are compared with the experimental nqcc's of Hopf et al. [1] in Tables 1 and 2.  Structure parameters are given in Table 3, rotational constants and dipole moments in Table 4.

 








In Tables 1 - 2, 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.  (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.


RMS is the root mean square differene between calculated and experimental nqcc's (percent of average experimental nqcc).  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's.

 








 








   







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

 









Calc.
Expt. [1]
   







14N(1,3) Xaa - 3.021 - 2.93716(20)


Xbb
0.858
0.80706(57)


Xcc
2.164
2.13010(37)


|Xab|
2.756
2.79(12)

 







RMS
0.060 (3.1 %)




RSD
0.030 (1.3 %)



 






  Xxx
2.288
2.29(10)


Xyy
2.164
2.13010(37)


Xzz - 4.452 - 4.42(10)


ETA - 0.0280 - 0.037(23)


z,b
62.57
61.94(60)


b,CN
62.87




z,CN
  0.30



 







 








 








   







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

 









Calc.
Expt. [1]
   







14N(2) Xaa
2.286
2.28913(31)


Xbb - 4.523 - 4.47658(90)


Xcc
2.237
2.18745(59)

 







RMS
0.039 (1.3 %)




RSD
0.030 (1.3 %)



 






  Xxx
2.286
2.28913(31)


Xyy
2.237
2.18745(59)


Xzz - 4.523 - 4.47658(90)


ETA - 0.0109 - 0.02271(20)

 







 








 







 
 



Table 3.  1,2,3-Tricyanobenzene.  Selected structure parameters, ropt ( and degrees).  Complete structure is given here in Z-matrix format.
 



C(6)C(10) 1.4279
C(10)N 1.1588
C(6)C(10)N 178.17
 
C(5)C(12) 1.4255
C(12)N 1.1587
C(5)C(12)N 180.00
 
C(4)C(14) 1.4279
C(14)N 1.1588
C(4)C(14)N 178.17
 






 








 












Table 4.  1,2,3-Tricyanobenzene.  Rotational Constants (MHz) and Dipole Moments (D).
 




   ropt     Expt [1]





A 1423.49 1413.898772(14)

B   892.50   893.252893(12)

C   548.56   547.3164030(58)

 


|b|   7.77


 








 









[1] H.Hopf, C.Mlynek, R.J.McMahon, J.L.Menke, A.Lesarri, M.Rosemeyer, and J.-U.Grabow, Chem.Eur.J. 16,14115(2010).

 









 








Benzonitrile 1,2,4-Tricyanobenzene

Chlorobenzonitrile Tolunitrile

Fluorobenzonitrile Cyanophenol

 








 








Table of Contents





Molecules/Nitrogen




 








 













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Last Modified 14 Nov 2010