CH3CH2-NH-CH2CH3
 

 








Nitrogen


Nuclear Quadrupole Coupling Constants

in Diethylamine


 







 
 
Nitrogen nqcc's in diethylamine were determined by Nguyen and Stahl [1].  
 
Calculation of the 14N nqcc tensors was made here on molecular structures derived by MP2/6-311+G(d,p), MP2/6-311+G(df,pd), and MP2/6-311+G(3df,3pd) optimizations.  Calculated and experimental nqcc's are compared in Table 1.  Structure parameters are given in Table 2, rotational constants and dipole moment components 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.  Ø (degrees) is the angle between its subscripted parameters.  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 nitrogen nqcc's.
 
 
   







Table 1.  14N nqcc's in Diethylamine (MHz).  Calculation was made on (1) MP2/6-311+G(d,p), (2) MP2/6-311+G(df,pd), and (3) MP2/6-311+G(3df,3pd) optimized molecular structures.
   








Calc. (1)

Calc. (2) Calc. (3)
Expt. [1]
   






Xaa 2.689 2.675 2.669 2.67576(37)
Xbb 0.769 0.806 0.861 0.83284 *
Xcc - 3.458 - 3.481 - 3.530 - 3.50860 *
|Xbc| 3.041 3.041 2.990 2.9199(92)
 
RMS 0.047 (2.0 %) 0.022 (0.96 %) 0.020 (0.88 %)
RSD 0.030 (1.3 %) 0.030 (1.3 %) 0.030 (1.3 %)
 
Xxx 2.359 2.383 2.375 2.30050
Xyy 2.689 2.675 2.669 2.67576
Xzz - 5.048 - 5.058 - 5.044 - 4.97626
ETA 0.0652 0.0577 0.0583 0.075
Øz,c 152.40 152.59 153.14
Øc,NH   41.64   42.18   42.53
Øz,NH 110.76 110.41 110.61
 
 
* Calculated here from Xaa and Xbb - Xcc = 4.34144(65) MHz [1].
 
 
Table 2.  Diethylamine.  Selected structure parameters (Å and degrees).  Complete structures are given here in Z-matrix format.
 
ropt (1) = MP2/6-311+G(d,p) optimization.
ropt (2) = MP2/6-311+G(df,pd) optimization.
ropt (3) = MP2/6-311+G(3df,3pd optimization.
 
ropt (1) ropt (2) ropt (3)
NC(3) 1.4606 1.4549 1.4558
C(3)C(9) 1.5232 1.5183 1.5172
NC(3)C(9) 110.67 110.78 110.61
NH 1.0183 1.0166 1.0150
C(3)NH 108.56 108.81 108.76
C(9)C(3)NH   56.43   55.91   55.65
 
 
Table 3.  Diethylamine.  Rotational constants (GHz) and dipole moment components (D). 
 
ropt (1) = MP2/6-311+G(d,p) optimization.
ropt (2) = MP2/6-311+G(df,pd) optimization.
ropt (3) = MP2/6-311+G(3df,3pd) optimization.
 
  Calc. ropt (1) Calc. ropt (2) Calc. ropt (3)    Expt. [1]
A 17.710 17.823 17.829 17.61499170(11)
B   2.105   2.118   2.123   2.103650248(49)
C   1.983   1.995   1.999   1.98133250(47)
 
b|   0.41   0.39   0.40
c|   0.90   0.89   0.90
 
 
[1] H.V.L.Nguyen and W.Stahl, J.Chem.Phys. 135,024310(2011)

 








 







NH3 CH3NH2 CH3CH2NH2
Dimethylamine Trimethylamine Quinuclidine
 

 








Table of Contents



Molecules/Nitrogen
 

 













Diethylamine.html






Last Modified 14 July 2011