CH3-NC4H8



 


























 








 









Nitrogen


Nuclear Quadrupole Coupling Constants

in equatorial N-Methylpyrrolidine

 








 








 








Calculation was made here of the N nqcc tensor in N-Methylpyrrolidine on molecular structures given by B3P86/6-31G(d,p) and B3P86/6-31G(3d,3p) optimization.  These nqcc's are compared with experimental values [1] in Table 1.  Structure parameters are given in Table 2, rotational constants and dipole moments 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 (percent of average absolute experimental nqcc).  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 N-Methylpyrrolidine (MHz).  Calculation was made on (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3p) optimized molecular structures.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa
2.584
2.593
2.729(119)

Xbb
2.670
2.688
2.494(80)

Xcc - 5.255 - 5.281 -
 5.223

|Xac|
0.593
0.565



 







RMS
0.133 (3.8 %)
0.141 (4.0 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
2.629
2.633



Xyy
2.670
2.688



Xzz - 5.299 - 5.322



ETA
0.0078
0.0103



Øz,a
  94.30
  94.08



Øa,N-Me
  13.58
  13.74



Øz,N-Me
107.88
107.83



 








 








 








 


Table 2.  N-Methylpyrrolidine.  Selected structure parameters (Å and degrees).  ropt(1) = B3P86/6-31G(d,p) and ropt(2) = B3P86/6-31G(3d,3p) optimized molecular structures.  Complete structures are given here in Z-matrix format.
 




ropt(1) ropt(2)



NC(14) 1.4418 1.4414
NC(1,4) 1.4542 1.4543
C(14)NC(1,4) 114.04 114.04
C(1)NC(4) 104.40 104.59















 








 













Table 3.  N-Methylpyrrolidine.  Rotational constants (MHz)and dipole moments (D).  ropt(1) = B3P86/6-31G(d,p) and ropt(2) = B3P86/6-31G(3d,3p) optimized molecular structures.
 





ropt(1) ropt(2)   Expt [1]






A 6672.8 6674.5 6636.726(1)

B 3168.0 3172.3 3154.4941(5)

C 2358.3 2359.0 2351.6616(4)

 



|µa|  0.12  0.13  0.08(1)

|µb|  0 (sym)  0 (sym)  0.0

|µc|  0.56  0.56  0.566(3)


 








 








[1] W.Caminati and F.Scappini, J.Mol.Spectrosc. 117,184(1986).

 








 








Pyrrolidine Nicotine



 








 








Table of Contents




Molecules/Nitrogen




 








 













NMePRL.html






Last Modified 29 June 2010