NH2CH2CN































 









Nitrogen


Nuclear Quadrupole Coupling Constants

in Aminoacetonitrile

 








 








 

 





Calculation of the nitrogen nuclear quadrupole coupling constant tensors in aminoacetonitrile was made here on ropt molecular structures given by MP2/aug-cc-pVTZ optimization with corrected CN bond length and MP2/6-311+G(3df,3pd) optimization also with corrected CN bond length.

 








Calculated and experimental [1] nqcc's are compared in Tables 1 and 2, structure parameters in Table 3, rotational constants and electric dipole moments in Table 4.  Calculated and experimental [3] quartic centrifugal distortion constants are compared in Table 5.

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.  14Namine nqcc's in NH2CH2CN (MHz).  Calculation was made on the (1) MP2/aug-cc-pVTZ and (2) MP2/6-311+G(3df,3pd) ropt structure, each with corrected CN bond length.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa -
 2.964
 -
 2.980
 -
 2.77(4)

Xbb
1.259
1.271
1.20(9)

Xcc
1.705
1.709
1.57

Xab
3.416
3.403



 







RMS
0.141 (7.6 %)
0.151 (8.2 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
3.163
3.158



Xyy
1.705
1.709



Xzz -
 4.868
 -
 4.967



ETA
 -
 0.300
 -
 0.298



Øz,CN
104.88
104.94



 








 








 








   







Table 1.  14Ncyano nqcc's in NH2CH2CN (MHz).  Calculation was made on the (1) MP2/aug-cc-pVTZ and (2) MP2/6-311+G(3df,3pd) ropt structure, each with corrected CN bond length.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa -
 3.412
 -
 3.413
 -
 3.48(3)

Xbb
1.411
1.409
1.50(6)

Xcc
2.001
2.004
1.98

Xab
2.245
2.242



 







RMS
0.066 (2.8 %)
0.067 (2.9 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
2.294
2.290



Xyy
2.001
2.004



Xzz -
 4.295
 -
 4.294



ETA
 -
 0.068
 -
 0.067



Øz,a
21.48
21.46



Øa,CN
21.82
21.69



Øz,CN
  0.34
  0.24



 








 








 












Table 3.  NH2CH2CN  MP2/aug-cc-pVTZ and MP2/6-311+G(3df,3pd) optimized structure parameters (Å and degrees).  Approximate equilibrium CN bond lengths are given in parentheses.





 C
 H,1,B1
 H,1,B2,2,A1
 N,1,B3,3,A2,2,D1,0
 H,4,B4,1,A3,3,D2,0
 H,4,B5,1,A4,3,D3,0
 C,1,B6,4,A5,5,D4,0
 N,7,B7,4,A6,1,D5,0


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




 B1=1.08888199
 B2=1.08888199
 B3=1.45636444
 B4=1.01262322
 B5=1.01262322
 B6=1.4736004
 B7=1.17130892  (1.1564)
 A1=107.06343265
 A2=109.07369859
 A3=110.25234117
 A4=110.25234117
 A5=114.80284388
 A6=145.00555099
 D1=117.89279675
 D2=62.86715933
 D3=-179.48683459
 D4=-58.82300304
 D5=180.
  B1=1.0883125
 B2=1.0883125
 B3=1.45487745
 B4=1.01212781
 B5=1.01212781
 B6=1.47373967
 B7=1.17010271  (1.1565)
 A1=107.10736205
 A2=109.06696765
 A3=110.25600945
 A4=110.25600945
 A5=114.68785819
 A6=145.14725342
 D1=117.90558855
 D2=62.85390114
 D3=-179.51862816
 D4=-58.81373535
 D5=180.







 







 






Table 4.  NH2CH2CN.  Rotational Constants (MHz) and Dipole Moments * (D).  ropt(1) = MP2/aug-cc-pVTZ and ropt(2) = MP2/6-311+G(3df,3pd), each with corrected CN bond length.

 





 ropt(1)  ropt(2)   Expt [2,3]
Ref.

 




 A
 30196.4
 30231.8
 30246.48715(90)
 [3]

 B
   4793.4
   4797.3
   4761.061966(146)
 [3]

 C
   4341.2
   4345.0
   4310.748772(150)
 [3]

|µa|   2.55
   2.55
   2.577(7)
 [2]

|µb|   0.54
   0.54
   0.5754(10)
 [2]

 




* Calculated by B3PW91/6-311+G(df,pd) method on MP2 ropt structures.



 








 
















Table 5.  NH2CH2CN.  Quartic Centrifugal Distortion Constants (kHz).  Calc(1) = B3LYP/cc-pVTZ and Calc(2) = MP2/cc-pVTZ.











Calc(1)
Calc(2)
Expt [3]









D_J
3.06
3.07
3.066693(136)

D_JK
 -
 55.7
 -
 56.4
 -
 55.29480(85)

D_K
699.
699.
714.0098(97)

d_1
 -
 0.663
 -
 0.674
 -
 0.6731843(229)

d_2
 -
 0.0278
 -
 0.0291
 -
 0.0299408(66)



 








 








[1] R.D.Brown, P.D.Godfrey, A.L.Ottrey, and J.W.V.Storey, J.Mol.Spectrosc. 68,359(1977).

[2] H.M.Pickett, J.Mol.Spectrosc. 46,335(1973).

[3] Y.Motoki, Y.Tsunoda, H.Ozeki, and K.Kobayashi, Abstract TH09, 67th International Symposium on Molecular Spectroscopy, 2012.

 








 








 








Table of Contents




Molecules/Nitrogen




 








 













NH2CH2CN.html






Last Modified 1 Jan 2014