C7H12N2O2











 


























 









Nitrogen


Nuclear Quadrupole Coupling Constants

in N-Acetyl-Prolinamide

 








 








 

 





Calculation of the 14N nuclear quadrupole coupling constant tensors in N-acetyl-prolinamide was made here on ropt molecular structures given by MP2/6-311++G(d,p) and B3P86/6-31G(3d,3p) optimization.

 








Calculated and experimental [1] nitrogen nqcc's are compared in Tables 1 and 2.  Structure parameters are given here in Z-Matrix format.  Rotational constants are given in Table 2.

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.  RMS is the root mean square difference between calculated and experiment diagonal nqcc's (percent of average magnitude of experimental 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.  14Npro nqcc's in N-Acetyl-Prolinamide (MHz).  Calculation was made on (1) MP2/6-311++G(d,p) and (2) B3P86/6-31G(3d,3p) ropt structures.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa
1.452
1.449
1.5087(89)

Xbb
1.312
1.232
1.1955(94)

Xcc -
 2.764
 -
 2.681
 -
 2.7041(94)

Xab -
 0.381
 -
 0.377



Xac -
 1.775
 -
 1.742



Xbc -
 2.184
-
 2.220


 







RMS
0.083 (4.6 %)
0.042 (2.3 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
1.769
1.732



Xyy
2.499
2.489



Xzz -
 4.269
 -
 4.221



ETA
0.171
0.179



 








 








 








   







Table 2.  14Nam nqcc's in N-Acetyl-Prolinamide (MHz).  Calculation was made on (1) MP2/6-311++G(d,p) and (2) B3P86/6-31G(3d,3p) ropt structures.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa
0.255
0.384
0.3593(99)

Xbb
1.397
1.409
1.4453(99)

Xcc -
 1.652
 -
 1.794
 -
 1.8047(99)

Xab -
 0.884
 -
 0.766



Xac
1.776
1.670



Xbc
1.753

 1.784


 







RMS
0.110 (9.2 %)
0.026 (2.2 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
1.298
1.260



Xyy
2.200
2.205



Xzz -
 3.498
 -
 3.465



ETA
0.258
0.273



 








 








 







 





Table 3.  N-Acetyl-Prolinamide. Rotational Constants (MHz).  ropt(1) = MP2/6-311++G(d,p), ropt(2) = B3P86/6-31G(3d,3p).

 




ropt(1) ropt(2)      Expt [1]

 



A
 1493.3
 1509.5
 1511.25246(49)

B
 1070.5
 1071.6
 1060.22862(81)

C
   718.5
   716.2
   714.486762(81)



 








 








[1] C.Cabezas, M.Varela, J.L.Alonso, ChemPhysChem 14,2539(2013).

 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 29 Oct 2013