HCC-CH2CH2CH2CN


 








Nitrogen


Nuclear Quadrupole Coupling Constants


in 5-Hexynenitrile anti-gauche


 







 
 
Calculation of the nitrogen nqcc's in the anti-gauche conformer of 5-hexynenitrile was made on an approximate equilibrium molecular structure (~ re) derived ab initio as described here. These nqcc's are compared in Table 1 with the experimental values of Utzat et al. [1].  Structure parameters are given in Table 2, rotational constants in Table 3.
 
Subscripts a,b,c refer to the principal axes of the inertia tensor, subscripts x,y,z to the principal axes of the nqcc tensor.  Øz,CN (degrees) is the angle between the z-principal axis and the CN bond axis.  ETA = (Xxx - Xyy)/Xzz.
 
RMS is the root mean square difference between calculated and experimental nqcc's (percentage of average experimental nqcc).  RSD is the residual standard deviation of calibration of 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.
 
 
   







Table 1. Nitrogen nqcc's in 5-Hexynenitrile, anti-gauche (MHz).  Calcculation was made on the ~ re structure.
   










Calc.
Expt. [1]
   






14N Xaa 0.514 0.502(5)
Xbb - 2.503 - 2.493(3)
Xcc 1.990 1.991
|Xab| 2.782 *
|Xac| 0.392
|Xbc| 0.577
 
RMS 0.009 (0.55 %)
RSD 0.030 (1.3 %)
 
Xxx 2.185
Xyy 2.053
Xzz - 4.238
ETA - 0.031
Øz,CN   0.25
 
   
* The algebraic sign of the product XabXacXbc is negative.
 
   
Table 2.  5-Hexynenitrile, anti-gauche.  Heavy atom molecular structure parameters (Å and degrees).  ~ re with interatomic angles given by MP2/6-311+G(2d,p) optimization.  Complete structure is given here in Z-matrix format.
   

NC(2) 1.1564
C(2)C(3) 1.4622
C(3)C(4) 1.5282
C(4)C(5) 1.5274
C(5)C(12) 1.4594
C(12)C(13) 1.203 (assumed)
NC(2)C(3) 178.58
C(2)C(3)C(4) 111.82
C(3)C(4)C(5) 112.11
C(4)C(5)C(12) 111.66
C(5)C(12)C(13) 178.42
Click on image to enlarge.
 
 
Table 3.  Rotational Constants (MHz).
Calc. ~ re    Expt. [1]
A 7 384.8 7 372.7740(6)
B 1 201.8 1 191.17918(15)
C 1 088.3 1 078.87035(9)
 
 
[1]  K.A.Utzat, Ph.D Dissertation, University of Connecticut, 2004.  Advisor:  R.K.Bohn.

 








 







5-Hexynenitrile, anti-anti n-Butyl Cyanide, anti-anti

5-Hexynenitrile, gauche-anti n-Butyl Cyanide, anti-gauche
n-Butyl Cyanide, gauche-anti
 

 








Table of Contents



Molecules/Nitrogen
 

 













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Last Modified 24 April 2008