CH3-N=CH2
































 









Nitrogen


Nuclear Quadrupole Coupling Constants

in N-Methylmethanimine


 








 


















14N nqcc's in N-methylmethanimine were determined by Sastry and Curl [1] in 1964, and in the perdeuterated species by Demaison et al. [2] in 1984.


 


 





Calculation of the nitrogen nqcc's was made here on ropt molecular structures given by MP2/6-311+G(3df,3pd) and MP2/aug-cc-pVTZ optimization.


 








Calculated and experimental [1] nqcc's are compared in Tables 1 and 2, structure parameters in Table 3.


In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  ETA = (Xxx - Xyy)/Xzz.  Ø (degrees) is the angle between its subscripted parameters.  RMS is the root mean square difference between calculated and experimental diagonal nqcc's.  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's. 


 








 








   








Table 1.  14N nqcc's in CH3-N=CH2 (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures.

   










Calc (1)
Calc (2)

Expt [1]

   








Xaa
1.248

1.248

1.9(3)


Xbb -
4.923
-
4.908
-
5.1(2)


Xcc
3.674

3.660

3.2(2)


Xab -
0.495
-
0.492




 







RMS

0.48 (14.0 %)

0.47 (13.9 %)



RSD
0.030 (1.3 %)

0.030 (1.3 %)



 









 








 









   








Table 2.  14N nqcc's in CD3-N=CD2 (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures.

   










Calc (1)
Calc (2)

Expt [2]

   








Xaa
1.246

1.245

1.28(37)


Xbb -
4.920
-
4.906
-
4.87(19)


Xcc
3.674

3.660

3.59(18)


Xab -
0.512
-
0.509




 







RMS

0.060 (1.8 %)

0.049 (1.5 %)




RSD
0.030 (1.3 %)

0.030 (1.3 %)



 








Xxx
1.288

1.287




Xyy
3.674
3.660



Xzz -
4.962
-
4.947




ETA
-
0.481
-
0.480




Øz,a

85.29

85.30




Øa,bi*
93.55

93.57




Øz,bi
  8.27

  8.27




 









 









* "bi" is bisector of CNC angle.


 













Table 3.  CH3-N=CH2  MP2/6-311+G(3df,3pd) and MP2/aug-cc-pVTZ optimized structure parameters (Å and degrees).





 C
 N,1,B1
 C,2,B2,1,A1
 H,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 H,1,B5,2,A4,3,D3,0
 H,3,B6,2,A5,1,D4,0
 H,3,B7,2,A6,1,D5,0


6-311+G(3df,3pd) aug-cc-pVTZ




 B1=1.45045368
 B2=1.27050843
 B3=1.09559474
 B4=1.0882495
 B5=1.0882495
 B6=1.09479038
 B7=1.08431364
 A1=116.71043757
 A2=113.15306838
 A3=108.7683087
 A4=108.7683087
 A5=122.90735164
 A6=119.10506967
 D1=0.
 D2=-121.65684202
 D3=121.65684202
 D4=0.
 D5=180.
 B1=1.45254809
 B2=1.27235627
 B3=1.09617643
 B4=1.08900721
 B5=1.08900721
 B6=1.09520078
 B7=1.08463103
 A1=116.47690775
 A2=113.0845688
 A3=108.78391738
 A4=108.78391738
 A5=122.91442925
 A6=119.08927572
 D1=0.
 D2=-121.63488962
 D3=121.63488962
 D4=0.
 D5=180.
 






 








[1] K.V.L.N.Sastry and R.F.Curl, J.Chem.Phys. 41,77(1964).


[2] J.Demaison, J.Burie, J.M.Denis, and B.P.Van Eijck, J.Mol.Spectrosc. 107,250(1984).


 









 









Table of Contents




Molecules/Nitrogen




 








 













CH3NCH2.html






Last Modified 29 Dec 2013