NCH2CH




 








Nitrogen

Nuclear Quadrupole Coupling Constants


in 2H-Azirine


 








 








 








Calculation of the nitrogen nqcc's was made here on a ropt molecular structure derived by B3LYP/6-31G(3d,3p) optimization, and on an reSE structure derived by Császár et al. [1].  These are compared with the experimental nqcc's [2] in Table 1.  Structure parameters are given in Z-matrix format in Table 2, ropt rotational constants in Tables 3.

 








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.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the symmetry plane of the molecule.  Ø (degrees) is the angle between its subscripted parameters. ETA = (Xxx - Xyy)/Xzz.

 








RMS is the root mean square difference between calculated and experimental nqcc's (percentage of average experimental nqcc).  RSD is the residual stand deviation of calibration of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.

 








 








   







Table 1.  14N nqcc's in NCH2CH (MHz).  Calculation was made on ropt and reSE  structures.

   









Calc/ropt
Calc/reSE
Expt. [2]
   







Xaa
1.036
1.003
1.056(10)

Xbb - 3.446 -
 3.405
 - 3.431(10)

Xcc
2.410
2.402
2.375(11)

|Xab|
0.196
0.202



 







RMS
0.025 (1.1 %)
0.038 (1.6 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
1.045
1.012



Xyy
2.410
2.402



Xzz - 3.454 -
 3.414



ETA
0.395
0.407



Øz,b
2.50
2.62



Øb,N=C
2.07
2.18



Øz,N=C
4.57
4.80



 







   








 











Table 2. Molecular structure parameters, ropt and reSE (Å and degrees).




 N
 C,1,B1
 C,1,B2,2,A1
 H,3,B4,2,A3,1,D4,0
 H,2,B6,1,A5,3,180.,0
 H,3,B4,2,A3,1,-D4,0

      ropt       reSE

 B1=1.25174807
 B2=1.54563064
 B4=1.08682274
 B6=1.08403052
 A1=61.28963585
 A3=120.73892064
 A5=138.94984143
 D4=99.75331035
  B1=1.2546
 B2=1.5463
 B4=1.0809
 B6=1.0778
 A1=61.20925
 A3=120.42
 A5=139.06
 D4=99.38022






 












Table 3.  Rotational Constants (MHz)






  ropt     Expt. [1]





A 35 888. 35 615.5986(10)

B 22 375. 22 224.02407(62)

C 15 198. 15 064.61324(54)


 








 








[1] A.G.Császár, J.Demaison, and H.D.Rudolph, J.Phys.Chem. A, 119(9),1731(2015).   


[2] M.Bogey, J.-L.Destombes, J.-M.Denis, and J.-C.Guillemin, J.Mol.Spectrosc. 115,1(1986).

 








 








Ethylenimine Pyrazole
 Imidazole
 Piperidine

 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 7 Feb 2015