CH3C(=O)-N(H)-C6H5









 





 





 




















Nitrogen


Nuclear Quadrupole Coupling Constants

in trans-Acetanilide

(N-Phenylacetamide)

 








 

 





Calculation of the nitrogen nqcc's in acetanilide was made here on molecular structures given by HF/6-311+G(d,p) and HF/6-311++G(3df,3pd) optimizations, with Cs symmetry assumed.  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters are given in Table 2, rotational constants 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 Acetanilide (MHz).  Calculation was made on the (1) HF/6-311+G(d,p) and (2) HF/6-311++G(3df,3pd) optimized structures.
   









Calc. (1)
Calc. (2)
Expt. [1]
   







Xaa
2.083
2.065
2.0851(27)

Xbb
1.746
1.736
1.7338(38)

Xcc - 3.829 - 3.801 - 3.8189(38)

|Xab|
0.216
0.220



 







RMS
0.009 (0.38 %)
0.016 (0.62 %)



RSD
0.030 (1.3 %) 0.030 (1.3 %)


 







Xxx
1.640
1.626



Xyy
2.189
2.175



Xzz - 3.829 - 3.801



ETA
0.143
0.144



 








 







 
 


Table 2.  Acetanilide.  Structure parameters (Ĺ and degrees).
 



ropt (1) = HF/6-311+G(d,p) optimization.

ropt (2) = HF/6-311++G(3df,3pd) optimization.





 N
 C,1,B1
 O,2,B2,1,A1
 C,2,B3,1,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 H,4,B5,2,A4,1,D3,0
 H,4,B6,2,A5,1,D4,0
 H,4,B7,2,A6,1,D5,0
 C,1,B8,2,A7,3,D6,0
 C,9,B9,1,A8,2,D7,0
 C,9,B10,1,A9,2,D8,0
 C,10,B11,9,A10,1,D9,0
 H,10,B12,9,A11,1,D10,0
 C,11,B13,9,A12,1,D11,0
 H,11,B14,9,A13,1,D12,0
 C,14,B15,11,A14,9,D13,0
 H,12,B16,10,A15,9,D14,0
 H,14,B17,11,A16,9,D15,0
 H,16,B18,14,A17,11,D16,0















     ropt (1)      ropt (2)




 B1=1.36525997
 B2=1.19264516
 B3=1.51441203
 B4=0.99277855
 B5=1.07970096
 B6=1.08582905
 B7=1.08582905
 B8=1.40912719
 B9=1.38968931
 B10=1.39299231
 B11=1.3870695
 B12=1.0686616
 B13=1.38101153
 B14=1.07708392
 B15=1.38574257
 B16=1.07565629
 B17=1.0755183
 B18=1.07477692
 A1=124.22677931
 A2=113.60176467
 A3=115.84616791
 A4=108.67743428
 A5=110.53750606
 A6=110.53750606
 A7=129.39635062
 A8=123.8154982
 A9=116.86553858
 A10=119.32153931
 A11=120.22237736
 A12=120.6417535
 A13=119.79358525
 A14=120.32388988
 A15=118.6339602
 A16=119.37942342
 A17=120.52177375
 D1=180.
 D2=180.
 D3=180.
 D4=-59.94428519
 D5=59.94428519
 D6=0.
 D7=0.
 D8=180.
 D9=180.
 D10=0.
 D11=180.
 D12=0.
 D13=0.
 D14=180.
 D15=180.
 D16=180.
  B1=1.36151038
 B2=1.19025929
 B3=1.5129455
 B4=0.9904733
 B5=1.07710392
 B6=1.08347705
 B7=1.08347705
 B8=1.40511397
 B9=1.38661287
 B10=1.38981353
 B11=1.38354786
 B12=1.06606494
 B13=1.37745006
 B14=1.07471283
 B15=1.38226635
 B16=1.07327003
 B17=1.0731319
 B18=1.0722807
 A1=124.28886368
 A2=113.60653196
 A3=115.68547705
 A4=108.73332872
 A5=110.49802357
 A6=110.49802357
 A7=129.56135608
 A8=123.85240915
 A9=116.87531082
 A10=119.31739792
 A11=120.19669192
 A12=120.66770516
 A13=119.74302142
 A14=120.35026675
 A15=118.61137419
 A16=119.37256531
 A17=120.54845804
 D1=180.
 D2=180.
 D3=180.
 D4=-59.86329779
 D5=59.86329779
 D6=0.
 D7=0.
 D8=180.
 D9=180.
 D10=0.
 D11=180.
 D12=0.
 D13=0.
 D14=180.
 D15=180.
 D16=180.







 








 



Table 3.  Acetanilide.  Rotational Constants (MHz).
 




ropt (1) = HF/6-311+G(d,p) optimization.

ropt (2) = HF/6-311++G(3df,3pd) optimization.
 




  Calc. ropt (1) Calc. ropt (2)    Expt. [1]






A 3784.9 3802.6 3776.6016(12)

B   786.8
   789.8
   783.52386(18)

C   654.1
   656.6
   649.66235(20)


 








 








[1] C.Cabezas, M.Varela, W.Caminati, S.Mata, J.C.López, and J.L.Alonso, J.Mol.Specxtrosc. 268,42(2011).

 








W.Caminati, A.Maris, A.Millemaggi, New J.Chem. 24,821(2000).

 








 








Formamide Acetamide N-Ethylformamide


N-Acetylglycine trans-Formanilide cis-Formanilide

N-Methylacetamide Propionamide Amides

 








 








Table of Contents




Molecules/Nitrogen




 








 













Acetanilide.html






Last Modified 29 March 2015