t-CH3CH=NH PDF













 








Nitrogen


Nuclear Quadrupole Coupling Constants


in trans-Ethanimine


 








 








 








Nitrogen nqcc's in trans-ethanimine were determined by Krause and Sutter [1].   Earlier measurements had been made by Lovas et al. [2].  Calculation of the nqcc's was made here on B3P86/ and MP2/6-311+G(3d,3p) optimized molecular structures.  These results are compared with the experimental nqcc's in Table 1. Structure parameters are compared in Table 2, rotational constants in Table 3.

 








In Table 1, 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.

 








Subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular symmetry plane.  (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

 








 








   








Table 1.  14N nqcc's in t-CH3CH=NH (MHz).  Calculation was made on the B3P86/ and MP2/6-311+G(3d,3p) optimized structures.
   










Calc/B3P86

Calc/MP2
Expt. [1]
   








Xaa - 3.609 - 3.536 - 3.6066(13)

Xbb
0.541
0.504
0.5488(33)

Xcc
3.068
3.032
3.0578(33)

|Xab|
1.792
1.785



 







RMS
0.008 (0.33 %) 0.050 (2.1 %)


RSD
0.030 (1.3 %) 0.030 (1.3 %)


 







Xxx
1.208
1.179



Xyy
3.068
3.032



Xzz - 4.276 - 4.212



ETA
0.435
0.440



z,b
20.41
20.73



b,bi
26.72
26.14



z,bi *
  6.31

  5.41



 








 








* Angle between the z-axis and the bisector of the CNH angle.

 








 






Table 2.  Molecular structure parameters, B3P86 and MP2/6-311+G(3d,3p) ( and degrees).
 











B3P86
  MP2











NH
1.0221
1.0225



C(1)N
1.2665
1.2791



C(1)C(2)
1.4951
1.5012



C(1)H
1.0936
1.0898



C(2)Hs
1.0900
1.0886



C(2)Ha
1.0925
1.0901



HNC(1)
110.51
109.58



NC(1)C(2)
127.87
127.53



C(2)C(1)H
115.51
116.05



C(1)C(2)Hs
111.58
111.24



C(1)C(2)Ha
110.25
110.13



HaC(2)Ha
106.69
107.18


 








 



Table 3.  Rotational Constants (MHz).
 





B2P86 opt MP2 opt    Expt. [2]






A 50 843 50 386 49 960.6(117)

B   9907.1   9821.6   9828.21(15)

C   8735.3   8656.2   8650.29(15)


 








 








[1] H.Krause and D.H.Sutter, Z.Naturforsch. 46a,785(1991).

[2] F.J.Lovas, R.D.Suenram, D.R.Johnson, F.O.Clark, and E.Tiemann, J.Chem.Phys. 72,4964(1980).

 









L.Marguls, R.A.Motiyenko, J.-C.Guillemin, J.Cernicharo, 70TH International Symposium on Molecular Spectroscopy, JUNE 22-26, 2015 - CHAMPAIGN-URBANA, ILLINOIS

 








CH2NH CF2NH Ethylenimine


cis-Ethanimine (CH3)2NH



trans-syn-Propenimine trans-anti-Propenimine



 








 








Table of Contents




Molecules/Nitrogen




 








 













tEthanimine.html






Last Modified 25 Feb 2005