(CH3)2C2H2S


 
 

Sulfur


Nuclear Quadrupole Coupling Constants


in 2,2-Dimethylthiirane


 







 
 
The diagonal components of the nqcc tensor for 33S in 2,2-dimethylthiirane were determined by Grabow et al. [1].  Heavy atom rs and ro structures were determined by Hartwig and Dreizler [2].  Calculation of the nqcc tensor was made here on these structures, each with CH parameters determined by MP2/6-31G(d,p) and MP2/6-311+G(d,p) partial optimization.
Calculated and experimental nqcc tensors are compared in Tables 1 - 4.  Structure parameters are given in Table 5.
 
In Tables 1 - 4, 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.  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 standard deviation of calibration of the model for calculation of the nqcc's.
 
 
   







Table 1.  33S nqcc's in 2,2-Dimethylthiirane (MHz).  Calculation was made on the ro structure with CH parameters given by MP2/6-31G(d,p) partial optimization.
   






Calc [a] B3LYP/6-311G(3df,3p) model.
Calc [b] B3LYP/TZV+(3df,3p) model.
 


Calc. [a]
Calc. [b]
Expt. [1]
   






Xaa - 23.08 - 23.20 - 22.6390(23)
Xbb 47.85 47.95 47.1830(50)
Xcc - 24.76 - 24.75 - 24.5440(50)
|Xac|   8.38   8.35
 
RMS 0.49 (1.5 %) 0.56 (1.8 %)
RSD 0.39 (1.7 %) 0.35 (1.5 %)
 
Xxx - 15.50 - 15.59
Xyy - 32.34 - 32.36
Xzz 47.85 47.95
ETA 0.352 0.350
Øy,a 47.86 47.66
Øa,SC(2) 14.3 14.3
Øy,SC(2) 33.5 33.3
Øy,bi*   9.1   8.9
 
 
* The z-principal axis of the nqcc tensor is normal to the plane of the ring.  The y-principal axis makes an angle of 9.6o/9.4o with the bisector ( bi ) of the CSC angle.
 
 
   







Table 2.  33S nqcc's in 2,2-Dimethylthiirane (MHz).  Calculation was made on the ro structure with CH parameters given by MP2/6-311+G(d,p) partial optimization.
   






Calc [a] B3LYP/6-311G(3df,3p) model.
Calc [b] B3LYP/TZV+(3df,3p) model.
 


Calc. [a]
Calc. [b]
Expt. [1]
   






Xaa - 23.16 - 23.27 - 22.6390(23)
Xbb 47.85 47.95 47.1830(50)
Xcc - 24.69 - 24.68 - 24.5440(50)
|Xac|   8.39   8.36
 
RMS 0.49 (1.6 %) 0.56 (1.8 %)
RSD 0.39 (1.7 %) 0.35 (1.5 %)
 
Xxx - 15.50 - 15.59
Xyy - 32.34 - 32.36
Xzz 47.85 47.95
ETA 0.352 0.350
Øy,a 47.61 47.41
Øa,SC(2) 14.3 14.3
Øy,SC(2) 33.3 33.1
Øy,bi*   8.9   8.7
 
 
 
   







Table 3.  33S nqcc's in 2,2-Dimethylthiirane (MHz).  Calculation was made on the rs structure with CH parameters given by MP2/6-31G(d,p) partial optimization.
   






Calc [a] B3LYP/6-311G(3df,3p) model.
Calc [b] B3LYP/TZV+(3df,3p) model.
 


Calc. [a]
Calc. [b]
Expt. [1]
   






Xaa - 22.50 - 22.59 - 22.6390(23)
Xbb 47.50 47.60 47.1830(50)
Xcc - 25.00 - 25.00 - 24.5440(50)
|Xac|   9.55   9.52
 
RMS 0.33 (1.0 %) 0.36 (1.1 %)
RSD 0.39 (1.7 %) 0.35 (1.5 %)
 
Xxx - 14.12 - 14.20
Xyy - 33.39 - 33.40
Xzz 47.50 47.60
ETA 0.406 0.403
Øy,a 48.73 48.61
Øa,SC(2) 15.0 15.0
Øy,SC(2) 33.7 33.6
Øy,bi*   9.7   9.6
 
 
 
   







Table 4.  33S nqcc's in 2,2-Dimethylthiirane (MHz).  Calculation was made on the rs structure with CH parameters given by MP2/6-311+G(d,p) partial optimization.
   






Calc [a] B3LYP/6-311G(3df,3p) model.
Calc [b] B3LYP/TZV+(3df,3p) model.
 


Calc. [a]
Calc. [b]
Expt. [1]
   






Xaa - 22.60 - 22.69 - 22.6390(23)
Xbb 47.50 47.59 47.1830(50)
Xcc - 24.89 - 24.90 - 24.5440(50)
|Xac|   9.58   9.55
 
RMS 0.27 (0.87 %) 0.31 (0.99 %)
RSD 0.39 (1.7 %) 0.35 (1.5 %)
 
Xxx - 14.10 - 14.18
Xyy - 33.40 - 33.41
Xzz 47.50 47.59
ETA 0.406 0.404
Øy,a 48.41 48.29
Øa,SC(2) 15.05 15.05
Øy,SC(2) 33.4 33.2
Øy,bi*   9.4   9.3
 
 
 
Table 5.  2,2-Dimethylthiirane.  Heavy atom structure parameters, ro and rs [2] (Å and degrees).  Complete structures are given here in Z-matrix format.
 
    ro     rs

C(4)C(2) 1.509(4) 1.518
C(2)C(3) 1.513(10) 1.478
SC(2) 1.838(16) 1.820
SC(3) 1.821(7) 1.822
C(4)C(2)C(3) 116.8(5) 117.8
C(4)C(2)S 116.0(4) 116.2
C(2)C(3)S   66.2(4)   66.0
SC(2)C(3)   65.0(3)   66.1
C(2)SC(3)   48.8   47.9
 
 
[1] J.-U.Grabow, M.Onda, and H.Dreizler, Z.Naturforsch. 51a,1110(1996).
[2] H.Hartwig and H.Dreizler, Z.Naturforsch. 48a,1102(1993).
Related ...
B.Kirchner, H.Huber, G.Steinebrunner, H.Dreizler, J.-U.Grabow, and I.Merke, Z.Naturforsch. 52a,297(1997).

 







 
Thiirane Methylthiirane t-2,3-Dimethylthiirane
Ethylene Oxide
 

 








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Last Modified 11 April 2006