C5H11NO











 






 






 







Nitrogen



Nuclear Quadrupole Coupling Constants


in equatorial N-Methyl-Morpholine



 









 









 


 






Calculation of the nitrogen nqcc tensor in N-methyl-morpholine was made here on molecular structures given by PBE1PBE/6-311G(3d,3p) and mPW1PW91/6-311G(3d,3p) optimizations.  These are compared with the experimental nqcc's of Dass and Kewley [1] in Table 1.  Structure parameters in Z-matrix format are given here.  Rotational constants and dipole moments are given in Table 2.



 









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. Øc,z is the angle between the c and z-principal axes.  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 nqcc's.



 









 









   








Table 1.  14N nqcc's in N-methyl-morpholine (MHz).  Calculation was made on the (1) PBE1PBE/6-311G(3d,3p) and (2) mPW1PW91/6-311G(3d,3p) optimized structures.
   










Calc. (1)

Calc. (2)
 Expt. [1]
   








Xaa
2.690
2.699
2.4(1)


Xbb
2.614
2.624
2.6(3)


Xcc - 5.304 - 5.323 -
5.0(2)


|Xac|
0.636
0.649



 







RMS
0.24 (7.3 %)

0.25 (7.6 %)



RSD
0.030 (1.3 %) 0.030 (1.3 %)


 







Xxx
2.740
2.751



Xyy
2.614
2.624



Xzz - 5.354 - 5.375



ETA - 0.0235 - 0.0236



Øa,z
85.48

85.40




Øc,z
  4.52
  4.60




 









 









 









 



Table 2.  N-Methyl-Morpholine.  Rotational constants (MHz) and B3PW91/6-311+G(df,pd) calculated dipole moments (D).
 




ropt (1) = PBE1PBE/6-311G(3d,3p) optimization.

ropt (2) = mPW1PW91/6-311G(3d,3p) optimization.
 




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






A 4879.62 4874.07
4821.235(77)

B 2363.88 2362.59
2342.579(4)

C 1734.62 1732.74
1719.452(3)

 



a|   1.36
  1.37
  1.21(2)

b|   0 (sym)   0 (sym)   0 (sym)

c|   0.15   0.15
  0.10(3)








 









 









[1] S.C.Dass and R.Kewley, Can.J.Chem. 52,434(1974).



 









 









1-Methyl-4-Piperidone, eq.
Tropinone 1-Asabicyclo[2.2.2.]octane


Trimethylamine Tropane
(N-dimethyl)aniline



 









 









Table of Contents





Molecules/Nitrogen





 









 














NMeMorpholine.html






Last Modified 11 Dec 2011