C3H5NO









 





 





 













Nitrogen


Nuclear Quadrupole Coupling Constants

in 2-Oxazoline

 








 








Nitrogen nqcc's in 2-oxazoline were determined by Durig et al. [1].  Calculation of the nitrogen nqcc's was made here on a molecular structure of C1 symmetry given by MP2/cc-pV5Z optimization derived by Samdal et al. [2]; and on a molecular structure of Cs symmetry given by B3P86/aug-cc-pVTZ optimization.  These calculated nqcc's are compared with the experimental values in Table 1.  Structure parameters are given in Table 2.  Calculated and experimental rotational constants and centrifugal distortion constants are given 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.  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 of the B3PW91/6-311+G(df,pd) model for calculation of the nitrogen efg's/nqcc's.

 








 








   







Table 1.  14N nqcc's in 2-Oxazoline (MHz).  Calculation was made on the C1 and Cs optimized structures.

   









Calc. C1
Calc. Cs
Expt. [1]
   







Xaa -
 3.371 -
 3.496 -
 3.54

Xbb
1.971
2.051
2.03

Xcc
1.400
1.445
1.51

Xab -
 0.989
0.859



Xac -
 0.190
  ----



Xbc
0.052
  ----



 







RMS
0.121 (5.1 %)
0.047 (2.0 %)



RSD
0.030 (1.3 %) 0.030 (1.3 %)


 







Xxx
2.157
2.181



Xyy
1.397
1.445



Xzz - 3.554 - 3.626



ETA -
 0.214 -
 0.203



 








 







 
 


Table 2.  2-Oxazoline.  Structure parameters (Å and degrees).
 



C1 = MP2/cc-pV5Z optimization.

Cs = B3P86/aug-cc-pVTZ optimization.





 C
 O,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 N,1,B4,2,A3,3,D2,0
 H,1,B5,5,A4,4,D3,0
 H,3,B6,2,A5,1,D4,0
 H,3,B7,2,A6,1,D5,0
 H,4,B8,3,A7,2,D6,0
 H,4,B9,3,A8,2,D7,0









     C1      Cs




B1=1.354
B2=1.448
B3=1.535
B4=1.472
B5=1.079
B6=1.087
B7=1.084
B8=1.086
B9=1.084
A1=104.8
A2=104.0
A3=104.8
A4=125.3
A5=107.6
A6=107.9
A7=112.6
A8=112.6
D1=8.9
D2=-9.9
D3=177.9
D4=-111.0
D5=130.5
D6=-129.3
D7=108.0
  B1=1.34986267
 B2=1.44530626
 B3=1.53991491
 B4=1.26032942
 B5=1.08207032
 B6=1.08888141
 B7=1.08888141
 B8=1.09066379
 B9=1.09066379
 A1=105.37177065
 A2=103.86435901
 A3=119.96470603
 A4=125.44825138
 A5=107.94037378
 A6=107.94037378
 A7=112.67994337
 A8=112.67994337
 D1=0.
 D2=0.
 D3=180.
 D4=-121.0476441
 D5=121.0476441
 D6=-119.08384728
 D7=119.08384728







 








 






Table 3.  2-Oxazoline.  Rotational Constants (MHz), and Centrifugal Distortion Constants (kHz).
 







C1 = MP2/cc-pV5Z optimization.

Cs = B3P86/aug-cc-pVTZ optimization.
 







 
C1 [2]
  Cs *
   Expt. [2]









A
8565.5
8570.6
8473.4432(37)

B
8187.3
8221.1
8122.1705(37)

C
4428.5
4427.5
4384.0958(37)









Delta_J
2.81
2.74
2.664(45)

Delta_JK
 -
 1.47
 -
 2.56
 -
 1.9352(12)

Delta_K
 -
 0.491
 +
 0.205
 -
 0.035(23)

delta_J
0.0147
0.0287
0.019883(25)

delta_k
10.63
10.72
10.9754(10)

 






* This work, B3LYP/cc-pVTZ.


 








 








[1] J.R.Durig, S.Riethmiller, and Y.S.Li, J.Chem.Phys. 61,253(1974).

[2] S.Samdal, H.Møllendal, S.Reine, and J.-C.Guillemin, J.Phys.Chem. A 119,4875(2015).

 














Oxazole



 








 








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Molecules/Nitrogen




 








 













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Last Modified 17 April 2015