(CH3)2-N-C6H5






















 




 









Nitrogen


Nuclear Quadrupole Coupling Constants


in (N-Dimethyl)aniline (DMA)


 








 








 








Calculation was made of the N nqcc tensor in DMA (CS) on an ropt structure given by B3P86/6-31G(3d,3p) optimization.  These are compared with experimental nqcc's [1] below in Table 1.  Structure parameters are given in Table 2.  Rotational constants are given in Table 3.

 








In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to principal axes of the nqcc tensor.

RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation for the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's, which may be taken as an estimate of the uncertainty in the calculated nqcc's (notwithstanding inaccuracies in the optimized structure).

 








  








   






Table 1.  Nitrogen nqcc tensors in DMA (MHz).  Calculation was made of the ropt structure.

 









Calc.
Expt. [1]
   






14N Xaa
2.587
2.58(4)


Xbb
2.924
2.80(6)


Xcc - 5.511 - 5.39(6)


|Xac|
0.478



 







RMS
0.10 (2.8 %)




RSD
0.030 (1.3 %)



 







Xxx
2.615




Xyy
2.924




Xzz - 5.539



  ETA
0.0557



 






   








 








 

Table 2.  (N-Dimethyl)aniline, CS.  Selected structure parameters, ropt (Å and degrees).  Complete structure is given here in Z-matrix (G03 input file) format.
 



Parameter   ropt
 
C(7)N 1.3816
NC(13,17) 1.4419
C(7)NC(13,17) 119.46
C(13)NC(17) 118.82
Inversion Angle *   14.86
 
* Angle between the C(7)N direction and the bisector of the C(13)NC(17) angle.


Click on image to enlarge.



 








 













Table 3.  (N-Dimethyl)aniline.  Rotational constants (MHz).  
 



 

 Calc.  Expt., 0+ [1]







A 3510.4 3500.315(103)


B 1235.7 1226.667(4)


C   925.6   923.345(3)


 








 








N-(Dimethylamino)benzonitrile (CH3)3N Aniline



 








 








[1]  R.G.Bird, J.L.Neill, V.J.Alstadt, J.W.Young, B.H.Pate, and D.W.Pratt, J.Phys.Chem. A 115,9392(2011);    R.G.Bird, V.J.Alstadt, D.W.Pratt, J.L.Neill, and B.H.Pate, Abstract RH05, 65th OSU International Symposium on Molecular Spectroscopy, 2010.

 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 12 Sept 2011