CH3CH2NC













 








Nitrogen


Nuclear Quadrupole Coupling Constants


in Ethyl Isocyanide


 








 








 








Calculation of the nitrogen nqcc's in ethyl isocyanide was made on a structure obtained by B3P86/6-31G(3d,3p) optimization.  These are compared in Table 1 with the experimental nqcc's of Fliege and Dreizler [1].  Structure parameters are given 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 symmetry plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

 








 








   







Table 1. Nitrogen nqcc's in CH3CH2NC (MHz).  Calculation was made on B3P86/6-31G(3d,3p) optimized structure.
   










Calc.
Expt. [1]
   







14N Xaa
0.290
0.2532(59)


Xbb - 0.114 - 0.106(11)


Xcc - 0.176 - 0.148(11)


|Xab|
0.212



 







RMS
0.027 (16 %)




RSD
0.030 (1.3 %)



 







Xxx - 0.204




Xyy - 0.176




Xzz
0.381




ETA - 0.0735




Øz,a
22.98




Øa,NC
23.19




Øz,NC
  0.20



 







 








 

Table 2.  Molecular structure parameters, B3P86/6-31G(3d,3p) opt (Å and degrees).



H' lies in symmetry plane. CN 1.1709

NC(1) 1.4208

C(1)-C(2) 1.5220

C(1)H 1.0941

C(2)H' 1.0923
Z-Matrix C(2)H 1.0914

CNC(1) 178.69

NC(1)-C(2) 111.79

C(2)-C(1)H 110.86

C(1)-C(2)H' 109.66

C(1)-C(2)H 110.80


 








 








[1] E.Fliege and H.Dreizler, Z.Naturforsch. 40a,43(1985); G.Bestmann and H.Dreizler, Z.Naturforsch. 37a,58(1982).

 








 








CH2CHNC CH3NC CF3NC HCCNC

(CH3)3CNC C6H5NC CNCN HNC

 








 








Table of Contents




Molecules/Nitrogen




 








 













CH3CH2NC.html






Last Modified 3 Oct 2005