C6H5-C(=O)NH2









 




 




 





















Nitrogen


Nuclear Quadrupole Coupling Constants

in Benzamide


 








 


 





Calculation of the nitrogen nqcc's in benzamide was made here on molecular structures given by B3LYP/6-311++G(d,p) and B3LYP/6-311++G(3df,3pd) optimization.  These are compared with the experimental nqcc's of Aviles Moreno et al. [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.


 









NOTE:  This C1 conformer, at the B3LYP/6-311++G(d,p) level of theory, is more stable than the planar Cs conformer by 1.5 kJ/mole.


 








 









   








Table 1.  14N nqcc's in Benzamide (MHz).  Calculation was made on the (1) B3LYP/6-311++G(d,p) and (2) B3LYP/6-311++G(3df,3pd) optimized structures.
   










Calc. (1)

Calc. (2)
Expt. [1]
   








Xaa
1.967
1.972
1.89312(94)

Xbb
0.981
1.082
1.29001

Xcc - 2.948 - 3.054 - 3.18313(66)

Xab -
0.155 -
0.130



Xac
0.099

0.071




Xbc
2.948

2.245




 







RMS
0.228 (10.7 %)
0.148 (7.0 %)



RSD
0.030 (1.3 %) 0.030 (1.3 %)


 







Xxx
1.913
1.919



Xyy
2.140
2.122



Xzz - 4.053 - 4.041



ETA
0.0559
0.0504



 








 

















 
 


Table 2.  Benzamide.  ropt = (1) B3LYP/6-311++G(d,p) and (2) B3LYP/6-311++G(3df,3pd) optimized structure ( and degrees).
 








 C
 O,1,B1
 N,1,B2,2,A1
 H,3,B3,1,A2,2,D1,0
 C,1,B4,2,A3,3,D2,0
 C,5,B5,1,A4,2,D3,0
 C,5,B6,1,A5,2,D4,0
 C,6,B7,5,A6,1,D5,0
 H,6,B8,5,A7,1,D6,0
 C,7,B9,5,A8,1,D7,0
 H,7,B10,5,A9,1,D8,0
 C,8,B11,6,A10,5,D9,0
 H,8,B12,6,A11,5,D10,0
 H,10,B13,7,A12,5,D11,0
 H,12,B14,8,A13,6,D12,0
 H,3,B15,1,A14,2,D13,0














      ropt (1)       ropt (2)



 B1=1.22010586
 B2=1.37296355
 B3=1.00656666
 B4=1.50348744
 B5=1.3999567
 B6=1.39902899
 B7=1.39320215
 B8=1.08425222
 B9=1.39086977
 B10=1.0829969
 B11=1.39374053
 B12=1.08410427
 B13=1.08410369
 B14=1.0842341
 B15=1.00884313
 A1=121.67196264
 A2=121.11451427
 A3=121.99036618
 A4=123.14713977
 A5=117.582348
 A6=120.32164324
 A7=120.49666861
 A8=120.36399719
 A9=118.44948102
 A10=120.05477659
 A11=119.82166818
 A12=119.84151879
 A13=120.00737378
 A14=116.19246292
 D1=160.90997777
 D2=-178.97214321
 D3=157.72738001
 D4=-21.13246318
 D5=-179.47272753
 D6=-1.69363514
 D7=-179.96896784
 D8=0.1802869
 D9=-0.23493452
 D10=179.24068519
 D11=179.48589379
 D12=-179.84704858
 D13=7.31531461
 B1=1.21751725
 B2=1.36855485
 B3=1.00397102
 B4=1.5009681
 B5=1.396193
 B6=1.39538584
 B7=1.38952714
 B8=1.08174098
 B9=1.38720042
 B10=1.08048773
 B11=1.38999695
 B12=1.0815577
 B13=1.08156358
 B14=1.08173431
 B15=1.00645383
 A1=121.56793742
 A2=121.29361409
 A3=121.94025277
 A4=123.21998445
 A5=117.5892375
 A6=120.39073434
 A7=120.50627333
 A8=120.41452822
 A9=118.41225691
 A10=120.02392822
 A11=119.82946278
 A12=119.84551405
 A13=120.00303812
 A14=116.35556048
 D1=162.15280347
 D2=-179.02698039
 D3=158.89288957
 D4=-20.10664323
 D5=-179.50463032
 D6=-1.66166562
 D7=-179.94191267
 D8=0.16085249
 D9=-0.27102255
 D10=179.24658097
 D11=179.497947
 D12=-179.83919626
 D13=7.18330612








 








 



Table 3.  Benzamide.  Rotational Constants (MHz).  Calc = (1) B3LYP/6-311++G(d,p) and (2) B3LYP/6-311++G(3df,3pd) optimized structures.
 




  Calc (1)
Calc (2)    Expt. [1]






A   3821.
  3843.
3815.695178(310)

B   1211.
  1217.
1216.517274(88)

C     935.
    938.
  934.408639(77)


 








 








[1] J.R.Aviles Moreno, T.Deleporte, T.R.Huet, C.Puzzarini, and D.Petitprez, Abstract RC12, 60th International Symposium on Molecular Spectroscopy, Ohio State University, Columbus, Ohio, 2005.  Presentation can be found here.


 








 









Benzanilide








Formamide Acetamide N-Ethylformamidetrans-Acetanilide

N-Acetylglycine trans-Formanilide cis-Formanilide

N-Methylacetamide Propionamide Amides


 








 








Table of Contents




Molecules/Nitrogen




 








 













Benzamide.html






Last Modified 24 Feb 2016