CH3NH2

















 





 





 









Nitrogen


Nuclear Quadrupole Coupling Constants

in Methylamine


 








 








 


 





Calculation of the nitrogen nqcc's in methylamine was made here on a ropt molecular structure derived by all electron CCSD(T)/cc-pVQZ optimization [1].  These are compared with the experimental nqcc's [2,3] in Table 1.  Structure parameters are given in Table 2.


 








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 (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 nitrogen nqcc's.

 








 








   








Table 1.  14N nqcc's in Methylamine (MHz).  Calculation was made on the ropt structure [1].
   










Calc.

Expt. [2]
Expt. [3]
   








Xaa
2.475
2.4136(12)
2.4136(27)

Xbb - Xcc
6.200
6.0646(24)
6.3746(81)

Xbb
1.862
1.8255
1.9805

Xcc - 4.337 - 4.2391 - 4.3941

|Xac|
1.794





 







RMS

0.070 (2.4 %) 0.084 (2.8 %)

RSD

0.030 (1.3 %) 0.030 (1.3 %)

 







Xxx
2.919





Xyy
1.862





Xzz - 4.781





ETA - 0.221





Øz,a
76.11





Øa,NC
  3.29





Øz,NC
72.82





 








 








 







 



Table 2. Methylamine.  Molecular structure parameters, ropt = all electron  CCSD(T)/cc-pVQZ optimization [1]  (Å and degrees).  Z-Matrix.
 

Point Group: Cs
  ropt




NH 1.0096
CN 1.4609
CHa 1.0873
CHs 1.0932
HNH 106.08
HNC 109.95

NCHa 109.14

NCHs 114.95

HaCHa 107.21

HaCHs 108.06



 








 








[1] J.Demaison, A.G.Császár, I.Kleiner, and H.Møllendal, J.Chem.Phys.A 111,2574(2007).


[2] V.V.Ilyushin, E.A.Alekseev, S.F.Dyubko, R.A.Motiyenko, and J.T.Hougen, J.Mol.Spectrosc. 229,170(2005).

[3] M.Kreglewski, W.Stahl, J.-U.Grabow, and G.Wlodarczak, Chem.Phys.Lett. 196,155(1992).

 








M.Kreglewski, W.Jäger, and H.Dreizler, J.Mol.Spectrosc. 144,334(1990): CD3NH2

M.Kreglewski, D.Stryjewski, and H.Dreizler, J.Mol.Spectrosc. 139,182(1990): CD3ND2


M.Kreglewski, J.Mol.Spectrosc. 133,10(1989).

T.Iijima, Bull.Chem.Soc.Jpn. 59,853(1986).


K.Takagi and T.Kohma, J.Phys.Soc. Japan 30,1145(1971).

D.R.Lide, Jr. J.Chem.Phys. 27,343(1957).

 








 








Formamide Cyanamide Acetamide Urea


 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 19 Jan 2008