c-NCHC-CHCN




 








Nitrogen


Nuclear Quadrupole Coupling Constants


in Maleonitrile


 







 
 
Calculation of the nitrogen nqcc's in maleonitrile was made on the re molecular structure of Halter et al. [1].  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters are compared in Table 2.
 
In Table 1, 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 of the B3PW91/6-311+G(df,pd) model for calculation of the nitrogen nqcc's.
 
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.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
 
 
   







Table 1. Nitrogen nqcc's in Maleonitrile (MHz).  Calculation was made on the re structure of Halter et al. [1].
   










Calc.
Expt. [1]
   






14N Xaa 0.024 0.0579(15)
Xbb - 2.425 - 2.3730 *
Xcc 2.401 2.3150 *
|Xab| 3.070
 
RMS 0.064 (4.1 %)
RSD 0.030 (1.3 %)
 
Xxx 2.105
Xyy 2.401
Xzz - 4.506
ETA 0.065
Øz,a 55.87
Øa,CN 55.20
Øz,CN   0.67
 
 
* Calculated here from Xaa and Xbb - Xcc = - 4.688(2) MHz [1].
 
 
Table 2.  Maleonitrile.  Molecular structure parameters, re [1] (Å and degrees).
 
C=C 1.341
C-C 1.429
CN 1.157
CH 1.075
C=C-C 123.2
C-CN * 178.4
C=CH 119.4
   * N's tilt outward.
 
 
[1] R.J.Halter, R.L.Fimmen, R.J.McMahon, S.A.Peebles, R.L.Kuczkowski, and J.F.Stanton, J.Am.Chem.Soc 123,12353(2001). 
 

 







(Z)-pent-2-en-4-ynenitrile
CH2CHCN Methacrylonitrile
c-Crotononitrile t-Crotononitrile
 

 








Table of Contents



Molecules/Nitrogen
 

 













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Last Modified 23 Oct 2007