CH3-SiF2N=C=O
























 





 









Nitrogen


Nuclear Quadrupole Coupling Constants

in Methyldifluoroisocyanate Silane


 








 








 


 





Nitrogen nuclear quadrupole coupling constants in CH3SiF2NCO were determined by Guirgis et al. [1].

 








Calculation of the nqcc's was made here on molecular structures given by HF/6-31G(3d,3p) and HF/6-311G(3d,3p) optimization. These calculated nqcc's are compared with the experimental values in Table 1.  Structure parameters are given in Table 2, rotational constants in Table 3.


 








In Table 1, 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.  (degrees) is the angle between its subscript parameters.

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 efg's/nqcc's.

 








 








   








Table 1.  14N nqcc's in CH3SiF2NCO (MHz).  Calculation was made on the (1) HF/6-31G(3d,3p) and (2) HF/6-311G(3d,3p) structures.
   










Calc (1)

Calc (2)

Expt [1]
   








Xaa
1.885
1.855
1.896(7)

Xbb - 0.900 - 0.868 - 0.920(17)

Xcc - 0.985 - 0.987 - 0.977(10)

|Xab|
0.195
0.203



 







RMS
0.014 (1.1 %)
0.039 (3.0 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx - 0.913 - 0.883



Xyy - 0.985 - 0.987



Xzz
1.899
1.870



ETA
0.0379
0.0557



a,z
  3.98
  4.23



a,N=C
10.67

12.20




z,N=C
  6.69

  7.97




 








 








 








 
 



Table 2.  CH3SiF2NCO.  Molecular structure parameters ( and degrees): HF/6-31G(3d,3p) and HF/6-311G(3d,3p)
 




 C
 Si,1,B1
 N,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 O,4,B4,3,A3,2,D2,0
 F,2,B5,3,A4,4,D3,0
 F,2,B6,3,A5,4,D4,0
 H,1,B7,2,A6,3,D5,0
 H,1,B8,2,A7,3,D6,0
 H,1,B9,2,A8,3,D7,0







HF/6-31G(3d,3p) HF/6-311G(3d,3p)







 B1=1.83379219
 B2=1.68421839
 B3=1.1851452
 B4=1.14146129
 B5=1.57134125
 B6=1.57134125
 B7=1.08570327
 B8=1.08576031
 B9=1.08576031
 A1=112.08545025
 A2=156.94422095
 A3=177.68233815
 A4=108.36680033
 A5=108.36680033
 A6=110.74708713
 A7=110.66011968
 A8=110.66011968
 D1=180.
 D2=180.
 D3=-57.31017771
 D4=57.31017771
 D5=180.
 D6=59.93349503
 D7=-59.93349503
 B1=1.83308562
 B2=1.68670505
 B3=1.18339045
 B4=1.13749735
 B5=1.56968595
 B6=1.56968595
 B7=1.08334425
 B8=1.08341591
 B9=1.08341591
 A1=111.84097826
 A2=153.67292321
 A3=177.45870116
 A4=108.43130945
 A5=108.43130945
 A6=110.7989559
 A7=110.39215803
 A8=110.39215803
 D1=180.
 D2=180.
 D3=-57.44748122
 D4=57.44748122
 D5=180.
 D6=59.82666754
 D7=-59.82666754










 













Table 3.  CH3SiF2NCO.  Rotational Constants (MHz).







HF/6-31G(3d,3p) HF/6-311G(3d,3p)   Expt [1]






A
      3837.5
      3848.4
3827.347(7)

B
      1275.4
      1286.6 1264.5067(14)

C
      1247.4
      1259.4
1240.6182(11)



 









 








[1] G.A.Guirgis, J.S.Overby, M.H.Palmer, R.A.Peebles, S.A.Peebles, L.F.Elmuti, D.A.Obenchain, B.H.Pate, and N.A.Seifert, J.Phys.Chem. A 116,7822(2012).


 








 








HNCO ClNCO BrNCO INCO

CH3-CH2NCO CH3SiHF-NCO HF2SiNCO




1-Isocyanato-1-silacyclohexane, eq.






 








 









Table of Contents




Molecules/Nitrogen




 








 













CH3SiFNCO.html






Last Modified 9 Dec 2016