CH3CH2SiH2Cl






 








 








Chlorine


Nuclear Quadrupole Coupling Constants


in Ethylchlorosilane



 


















Chlorine nqcc's in both gauche and trans conformers of ethylchlorosilane were determined by Typke et al. [1]. 












gauche


trans


































At the MP2/6-311+G(d,p) level of theory, Egauche <  Etrans by 1.3 kJ/mole.


 








Calculation of the chlorine nqcc tensors in gauche and trans conformers was made here on molecular ro structure (structure II in Table 5 of ref. [1]), and on a structure given by MP2/6-311+G(d,p) optimization.  Calculated and experimental nqcc's are compared in Tables 1and 2.  Structure parameters are given in Z-matrix format 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, subscripts x,y,z to the principal axes of the nqcc tensor.   ETA = (Xxx - Xyy)/Xzz.  Ø (degrees) is the angle between its subscripted parameters.  RMS is the root measn square difference between calculated and experimental diagonal nqcc's.  RSD is the residual standard deviation of calibration of the B1LYP/TZV(3df,2p)  model for calculation of the efg's/nqcc's.

 








 








   








Table 1.  Chlorine nqcc's in gauche Ethylchlorosilane (MHz).  Calculation was made on experimental ro and MP2/6-311+G(d,p) optimized molecular structures.

   










Calc /ro

Calc /MP2

  Expt. [1] *

 








Xaa (35Cl) -
10.25

- 9.01

- 8.989(82)


Xbb
- 8.20

- 9.69

- 9.150(54)


Xcc
18.45

18.70

18.139(54)


Xab
27.67

28.32




Xac
  4.20

  4.55




Xbc
- 4.72

- 5.05




 








RMS

0.93 (7.7 %)

0.45 (3.7 %)




RSD
0.49 (1.1 %)
0.49 (1.1 %)


 







Xxx
18.22

18.82




Xyy
19.41

19.65




Xzz -
37.63
-
38.47




ETA
0.0315

0.0217




Øz,SiCl
0.55

0.73




 







Xaa (37Cl)
- 8.59

- 7.63

- 7.08(60)

Xbb
- 5.97

- 7.12

- 6.55(36)

Xcc
14.56

14.76

13.63(36)

Xab
21.80

22.33




Xac
  3.30

  3.58




Xbc
- 3.63

- 3.89













RMS

1.08 (11.9 %)

0.80 (8.8 %)




RSD

0.44 (1.1 %)
0.44 (1.1 %)













 








* Calculated here from experimental Xaa + Xbb = 8.989(82) and Xaa - Xbb = -27.289(71) MHz for 35Cl; and Xaa + Xbb = 7.08(60) and Xaa - Xbb = -20.17(39) MHz for 37Cl.

 









 









   








Table 2.  Chlorine nqcc's in trans Ethylchlorosilane (MHz).  Calculation was made on experimental ro and MP2/6-311+G(d,p) optimized molecular structures.

   










Calc /ro

Calc /MP2

Expt. [1] *

 








Xaa (35Cl) -
28.04
-
27.69
-
26.94(39)


Xbb
  8.63

  8.00

  7.9(17)


Xcc
19.41

19.69

19.1(17)


|Xab|
21.37

22.69




 








RMS

0.80 (4.4 %)

0.56 (3.1 %)




RSD
0.49 (1.1 %)
0.49 (1.1 %)


 







Xxx
18.45

19.02




Xyy
19.41

19.69




Xzz -
37.86
-
38.71




ETA
0.0251

0.0173




Øz,a
24.68

25.91




Øa,SiCl
25.15

25.30




Øz,SiCl
  0.47

  0.60




 







Xaa (37Cl) -
22.22
-
21.95
-
17.35(84)


Xbb
  6.93

  6.43

11.6(54)


Xcc
15.29

15.52

  5.8(54)


|Xab|
16.73

17.77













RMS

6.73 (58. %)

6.76 (58. %)




RSD

0.44 (1.1 %)
0.44 (1.1 %)













 









 * Calculated here from experimental Xaa + Xbb = 26.94(39) and Xaa - Xbb = -11.2(34) MHz for 35Cl; and Xaa + Xbb = 17.35(84) and Xaa - Xbb = 5.8(108) MHz for 37Cl.

 









 









 




Table 3. Ethylchlorosilane.  Experimental ro and MP2/6-311+G(d,p) optimized structure parameters (Å and degrees).
 





gauche Ethylchlorosilane









 C
 C,1,B1
 Si,2,B2,1,A1
 Cl,3,B3,2,A2,1,D1,0
 H,1,B4,2,A3,3,D2,0
 H,1,B5,2,A4,3,D3,0
 H,1,B6,2,A5,3,D4,0
 H,2,B7,1,A6,3,D5,0
 H,2,B8,1,A7,3,D6,0
 H,3,B9,2,A8,1,D7,0
 H,3,B10,2,A9,1,D8,0









      ro      MP2









B1=1.5318
B2=1.8694
B3=2.0601
B4=1.0823
B5=1.0823
B6=1.0823
B7=1.1071
B8=1.1071
B9=1.4780
B10=1.4780
A1=112.99
A2=109.89
A3=111.89
A4=111.89
A5=111.89
A6=112.08666953
A7=112.08666953
A8=113.82
A9=113.82
D1=59.63
D2=180.0
D3=60.0
D4=-60.0
D5=-117.95194779
D6=117.95194779
D7=-58.05
D8=177.31
 B1=1.53693569
 B2=1.86672263
 B3=2.06778962
 B4=1.09331176
 B5=1.09447426
 B6=1.09323248
 B7=1.09824099
 B8=1.09633512
 B9=1.47355417
 B10=1.47258133
 A1=113.90893516
 A2=109.17154389
 A3=111.08786329
 A4=111.1774821
 A5=111.11977662
 A6=110.02052054
 A7=110.26696279
 A8=110.90070391
 A9=111.78231871
 D1=60.23536391
 D2=178.61620057
 D3=58.65585532
 D4=-61.31150595
 D5=-120.51067997
 D6=122.57749789
 D7=-57.45779768
 D8=178.80814306


 





 





trans Ethylchlorosilane








 C
 C,1,B1
 Si,2,B2,1,A1
 Cl,3,B3,2,A2,1,D1,0
 H,1,B4,2,A3,3,D2,0
 H,1,B5,2,A4,3,D3,0
 H,1,B6,2,A5,3,D4,0
 H,2,B7,1,A6,3,D5,0
 H,2,B8,1,A7,3,D6,0
 H,3,B9,2,A8,1,D7,0
 H,3,B10,2,A9,1,D8,0









      ro      MP2









B1=1.5318
B2=1.8694
B3=2.0601
B4=1.0823
B5=1.0823
B6=1.0823
B7=1.1071
B8=1.1071
B9=1.4780
B10=1.4780
A1=111.30
A2=109.89
A3=111.89
A4=111.89
A5=111.89
A6=112.08666953
A7=112.08666953
A8=113.82
A9=113.82
D1=180.0
D2=180.0
D3=60.0
D4=-60.0
D5=121.83
D6=-121.83
D7=62.32
D8=-62.32
 B1=1.53870443
 B2=1.86693258
 B3=2.06616457
 B4=1.09328458
 B5=1.09439534
 B6=1.09439534
 B7=1.0959093
 B8=1.0959093
 B9=1.47319951
 B10=1.47319951
 A1=112.36148493
 A2=109.9516565
 A3=111.03306368
 A4=111.39550922
 A5=111.39550922
 A6=108.72466019
 A7=108.72466019
 A8=110.92623349
 A9=110.92623349
 D1=180.
 D2=180.
 D3=60.16666489
 D4=-60.16666489
 D5=122.22089491
 D6=-122.22089491
 D7=61.33378521
 D8=-61.33378521


 






 









 




Table 4.  Ethylchlorosilane, 35Cl species.  Rotational Constants (MHz).  Calc = ro [1] and MP2/6-311+G(d,p) optimized molecular structures.







    Calc /ro Calc /MP2     Expt. [1]





   gauche A
     7189.
    7133.
  7191.8752(59)

B
     2587.
    2577.
  2585.1897(33)

C
     2085.
    2075.
  2083.6754(33)





   trans A
   14740.
  14710.
14742.5(21)

B
     1876.
    1861.
  1876.7444(37)

C
     1734.
    1720.
  1733.8894(33)



  








[1] V.Typke, M.Dakkouri, and W.Zeil, Z.Naturforsch. 29a,1081(1974).


 









 








SiH3Cl
(CH3)3SiCl
CH3SiF2Cl


SiF3ClCH3SiH2Cl











 








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Molecules/Chlorine




 








 













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Last Modified 15 Jan 2016