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