Cotinine

 








 








Nitrogen

Nuclear Quadrupole Coupling Constants


in Cotinine


[1-Methyl-5-(3-pyridyl)(2-piperidyl)pyrrolidin-2-one]

 








 








Rotational spectra of two conformers of cotinine have been investigated by Uriarte et al. [1].

 








Calculation of the N nqcc tensors was made here on molecular structures optimized at the  B3P86/6-31G(3d,3p) level of theory.  These structures are shown below.  Calculated nqcc's are given in Tables 1 and 2.  Rotational constants and dipole moments are given in Table 3.

 









Conformer I    
     Conformer II




































 








Optimized structures of these conformers are given here in Z-matrix format.

 








In Tables 1 and 2, 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 (percent of the average of the magnitudes of experimental nqcc's).  RSD is the residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.

 








 








 
 





Table 1. 14N nqcc's in Cotinine I (MHz).  N(5) is pyrrolidinic nitrogen, N(19) is pyridinic.  Calculation was made on B3P86/6-31G(3d,3p) ropt structure.
 
 








Calc
  Expt [1]
 
 





14N(5) Xaa
0.963
1.09(11)


Xbb
1.984
2.09(25)


Xcc -
 2.947
 -
 3.17(25)


Xab -
 0.752




Xac
2.064




Xbc
1.259




 






RSD
0.030 (1.3 %)




 






Xxx
1.786




Xyy
2.392




Xzz -
 4.178




ETA
0.145




 






         ----------------------------------------------------------------------------


 





14N(19) Xaa - 1.824 -
 1.76(11)


Xbb
2.706
2.31(25)


Xcc -
 0.881 -
 0.55(25)


Xab
1.004




Xac -
 3.034




Xbc
1.826




 






RSD
0.030 (1.3 %)




 






Xxx
1.437




Xyy
3.490




Xzz - 4.927




ETA
0.416




 





   








 








 
 





Table 2. 14N nqcc's in Cotinine II (MHz).  N(5) is pyrrolidinic nitrogen, N(19) is pyridinic.  Calculation was made on B3P86/6-31G(3d,3p) ropt structure.
 
 








Calc
  Expt [1]
 
 





14N(5) Xaa
0.890
0.747(73)


Xbb
1.894
1.45(28)


Xcc -
 2.784
 -
 2.19(28)


Xab
0.861




Xac
2.110




Xbc -
 1.425




 






RSD
0.030 (1.3 %)




 






Xxx
1.788




Xyy
2.406




Xzz -
 4.194




ETA
0.147




 






         ----------------------------------------------------------------------------


 





14N(19) Xaa
1.217
1.215(65)


Xbb
1.344




Xcc -
 2.561




Xab
0.731




Xac
0.994




Xbc -
 2.561




 






RSD
0.030 (1.3 %)




 






Xxx
1.435




Xyy
3.525




Xzz -
 4.960




ETA
0.421




 






 








 












Table 3.  Cotinine.  Rotational constants (MHz) and dipole moments (D).  Calc is on the B3P86/6-31G(3d,3p) opt structure.

 


              ______________Conformer I_______________

 



Calc   Expt [1]

 


A 1909.8
 1911.19(12)

B   481.1
   478.56272(41)

C   452.2
   449.43077(45)

 


|µa|   1.64

|µb|   1.16

|µc|   0.51

 


              ______________Conformer II_______________

 


A 1891.5
 1893.66(11)

B   485.6
   482.65540(38)

C   454.9
   452.49336(39)

 


|µa|   2.78

|µb|   2.93

|µc|   2.83






 








 








Pyridine
 Anabasine Nicotine N-Methylpyrrolidine

 








 








[1] I.Uriarte, C.Perez, E.Caballero-Mancebo, F.J.Basterretxea, A.Lesarri, J.A.Fernández, and E.J.Cocinero, Chem.Eur.J. 23(30),7238(2017).

 








I.Uriarte, P.Ecija, E.J.Cocinero, C.Perez, E.Caballero-Mancebo, and A.Lesarri, Abstract TD05, 70th International Symposium on Molecular Spectroscopy, Champaign-Urbana, 2015.

 

 








Table of Contents




Molecules/Nitrogen




 








 













Cotinine.html






Last Modified 20 July 2015