CH2Cl-SiH2F
























 









Chlorine


Nuclear Quadrupole Coupling Constants


in Chloromethylfluorosilane


 








 








 








Calculation was made of the Cl nqcc tensors in CH2ClSiH2F on a molecular structure given by MP2/aug-cc-pVTZ optimization (ropt), and on this same structure but with an empirically corrected CCl bond length (ropt*).  These calculated nqcc's are compared with the experimental values of Guirgis et al. [1] in Tables 1 and 2.  Structure parameters are given in Table 3, rotational constants in Table 4.

 








In Tables 1 and 2, 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.  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 for the B1LYP/TZV(3df,2p) model for calculation of the chlorine efg's/nqcc's.

 








 







 
   







Table 1.  35Cl nqcc's in CH2ClSiH2F (MHz).  Calculation was made on ropt and ropt* molecular structures.
   









Calc / ropt
Calc / ropt*
Expt.  [1] *
   







Xaa - 46.05 - 45.93 -
 45.719(7)

Xbb
  6.90
  6.84
  7.130(8)

Xcc
39.15
39.09
38.589(8)

|Xab|
48.06
48.00
47.36(80)

 







RMS
0.40 (1.3 %)
0.36 (1.2 %)



RSD
0.49 (1.1 %)
0.49 (1.1 %)



 







Xxx
35.30
35.23
34.94(70)

Xyy
39.15
39.09
38.589(8)

Xzz - 74.45 - 74.32 -
 73.53(70)

ETA
0.0517
0.0520
0.0496(95)

Øz,a
30.57
30.60
30.42(21)

Øa,CCl
31.49
31.52



Øz,CCl
  0.91
  0.92



 








 








* Derived here from experimental 3/2(Xaa) = -68.578(11) and 1/4(Xbb - Xcc) = -7.8649(36) MHz using Kisiel's QDIAG program.

 








 








   







Table 2.  37Cl nqcc's in CH2ClSiH2F (MHz).  Calculation was made on ropt and ropt* molecular structures.
   









Calc / ropt
Calc / ropt*
Expt.  [1] *
   







Xaa - 36.40 - 36.31 -
 36.1420(59)

Xbb
  5.55
  5.50
  5.7226(63)

Xcc
30.85
30.81
30.4194(63)

|Xab|
37.82
37.77
36.76(70)

 







RMS
0.31 (1.2 %)
0.28 (1.1 %)



RSD
0.44 (1.1 %)
0.44 (1.1 %)



 







Xxx
27.82
27.76
27.09(61)

Xyy
30.85
30.81
30.4194(63)

Xzz - 58.67 - 58.57 -
 57.51(61)

ETA
0.0517
0.0520
0.0578(11)

Øz,a
30.49
30.52
30.17(23)

Øa,CCl
31.40
31.43



Øz,CCl
  0.91
  0.92



 








 








* Derived here from experimental 3/2(Xaa) = -68.578(11) and 1/4(Xbb - Xcc) = -7.8649(36) MHz using Kisiel's QDIAG program.

 












Table 3.  CH2ClSiH2F .  MP2/aug-cc-pVTZ structure parameters, ropt.  Approximate re CCl bond length is given in parentheses.  (Å and degrees)
 



 Cl
 C,1,R1
 Si,2,R2,1,A1
 F,3,R3,2,A2,1,D1,0
 H,3,R4,2,A3,1,D2,0
 H,3,R4,2,A3,1,D3,0
 H,2,R5,3,A4,4,D4,0
 H,2,R5,3,A4,4,D5,0





 R1=1.79628226    (1.7930)
 R2=1.87859873
 R3=1.61652231
 R4=1.47239195
 R5=1.08676262
 A1=104.81532975
 A2=108.85492055
 A3=109.56998201
 A4=113.49628553
 D1=180.
 D2=61.60193928
 D3=-61.60193928
 D4=62.74557721
 D5=-62.74557721



 













Table 4.  CH2ClSiH2F.  Rotational Constants,   ropt,   ropt*,  and experimental (MHz).
 





 ropt  ropt*     Expt [1]






A
 17752.
 17759.
17794.2740(20)

B
   1801.
   1803.
  1867.72449(64)

C
   1685.
   1687.
  1743.66072(51)


 








 








[1] G.A.Guirgis, D.K.Sawant, R.E.Brenner, B.S.Deodhar, N.A.Seifert, Y.Geboes, B.H.Pate, W.A.Herrebout, D.V.Hickman, and J.R.Durig, J.Phys.Chem. A 119,11532(2015).











 








CH2ClSiH3 CHCl2SiF3 CHCl2SiH3


CH2ClSiF3
 CH2ClCH3
 SiH2ClCH3



 







 









Table of Contents




Molecules/Chlorine




 








 













CH2ClSiH2F.html






Last Modified 11 March 2017