CH2CH3N(H)C(=O)H






















 








Nitrogen


Nuclear Quadrupole Coupling Constants


in N-Ethylformamide cis-anticlinal



 








 








 








Nitrogen nqcc's in N-ethylformamide were determined by Vaquero-Vara et al. [1].  Calculation of the nqcc's was made here on an optimized structure (ropt) given by HF/aug-cc-pVTZ optimization.  Calculated and experimental nqcc's are compared 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; 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 N-Ethylformamide (MHz).  Calculation was made on an ropt structure given by HF/aug-cc-pVTZ optimization.
 










Calc ropt
Expt. [1]
 







14N Xaa
1.813

1.843(3)


Xbb -
2.609
-
3.368(12)


Xcc
0.796

1.525(11)


Xab
-
1.318





Xac

0.387





Xbc

2.245













RMS

0.608 (27. %)





RSD
0.030 (1.3 %)












Xxx
1.761





Xyy
2.276





Xzz -
4.037





ETA
0.127













 








 








 

Table 2.  Molecular structure parameters, ropt = HF/aug-cc-pVTZ optimization. ( and degrees).






 C
 O,1,B1
 N,1,B2,2,A1
 C,3,B3,1,A2,2,D1,0
 C,4,B4,3,A3,1,D2,0
 H,3,B5,1,A4,2,D3,0
 H,1,B6,2,A5,3,D4,0
 H,4,B7,3,A6,1,D5,0
 H,4,B8,3,A7,1,D6,0
 H,5,B9,4,A8,3,D7,0
 H,5,B10,4,A9,3,D8,0
 H,5,B11,4,A10,3,D9,0


 B1=1.19103994
 B2=1.34256512
 B3=1.4450348
 B4=1.52221478
 B5=0.99392822
 B6=1.09163344
 B7=1.08416096
 B8=1.08215884
 B9=1.08307324
 B10=1.0838261
 B11=1.08423668
 A1=125.08032824
 A2=125.21388642
 A3=113.02453609
 A4=115.74950027
 A5=121.8119924
 A6=109.37629213
 A7=107.71735278
 A8=110.92224141
 A9=110.34028025
 A10=110.92515092
 D1=179.115137
 D2=-114.58715983
 D3=0.48325282
 D4=-179.87859817
 D5=122.6987187
 D6=7.15339199
 D7=60.89039397
 D8=-178.75013658
 D9=-59.21239225






 








 












Table 3. N-Ethylformamide.  Rotational constants (MHz):  ropt = HF/aug-cc-pVTZ.  Quantity in square brackets is held fixed in fit.
 




  ropt     Expt. [1]





A 19814.
[192221]

B   2376.
2378.124(1)

C   2324.
2320.822(9)


 








 








[1] V.Vaquero-Vara, V.Alstadt, T.P.Sewatsky, J.L.Claughton, I.A.Finneran, S.T.Shipman, B.H.Pate, and D.W.Pratt, J.Mol.Spectros. 335,102(2017).


 









 









Formamide Acetamide Dimethylamine


N-Methylacetamide N-Ethylformamide trans-sc




 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 6 July 2017