C6H11CN
























 






Nitrogen


Nuclear Quadrupole Coupling Constants


in axial Cyclohexyl Cyanide


 








 








 








Calculation of the nitrogen nqcc tensor in axial cyclohexyl cyanide was made on an ropt structure obtained by MP2/6-311+G(3df,3pd) optimization with approximate equilibrium C-Ccyan and CN bond lengths.  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters are given in Table 2, rotational constants in Table 3.

 








In Table 1, 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.  The nqcc y-axis is chosen coincident with the inertia b-axis, these are perpendicular to the molecular symmetry plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

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+(df,pd) model for calculation of the nitrogen nqcc's. 

 








 







 
   






Table 1. Nitrogen nqcc's in axial Cyclohexyl Cyanide (MHz).  Calculation was made on the MP2/6-311+G(3df,3pd) ropt structure with corrected C-Ccyan and CN bond lengths.
   









Calc.
Expt. [1]
   






14N Xaa - 0.969 - 1.0741(23)


Xbb
2.107
2.1336(17)


Xcc - 1.139 - 1.0595(8)


|Xac|
3.133



 







RMS
0.078 (5.4 %)




RSD
0.030 (1.3 %)



 







Xxx
2.107




Xyy
2.080




Xzz - 4.188




ETA - 0.006




Øz,a
45.78




Øa,CN
46.40




Øz,CN
  0.62



 







 








 

Table 2.  axial Cyclohexyl Cyanide.  Selected molecular structure parameters, ropt (Å and degrees).  The complete structure is given here is Z-matrix format.
 

 
  ropt




CN 1.1572
C(3)C 1.4643
C(3)C(2,4) 1.5365
C(3)CN 178.49
C(2)C(3)C(4) 110.48
C(2)C(1) 1.5248
C(1)C(6) 1.5263





 








 












Table 3.  axial Cyclohexyl Cyanide.  Rotational constants (MHz).






  ropt    Expt. [1]





A 3010.5 3004.7137(4)

B 1798.6 1765.1907(3)

C 1598.0 1561.4274(3)


 








 








[1] J.R.Durig, R.M.Ward, A.R.Conrad, M.J.Tubergen, K.G.Nelson, P.Groner, and T.K.Gounev, J.Mol.Struct. 967,99(2010).

 








 








equatorial Cyclohexyl Cyanide






 








 








Table of Contents




Molecules/Nitrogen




 








 













cycC6H11CN_ax.html






Last Modified 21 Jan 2010